McGhee v National Coal Board [1972] UKHL 11

UKHL

McGhee v National Coal Board

[1972] UKHL 11 · 1972-11-15

LORD KISSEN'S OPINION.—[His Lordship gave the narrative quoted supra , and continued]—The first question which I have to decide is whether the pursuer has established that the dermatitis from which he was admittedly suffering on 4th and 5th April 1967 was caused by "exposure to dust and ashes" in the course of his said work in the brick kiln. The defenders' case was that the pursuer did not contract the dermatitis because of the work in the kiln, and that this condition was constitutional and a "follicular seborrhoeic eczema."

The medical evidence for the pursuer was given by Dr Kerr, his general practitioner, and by Dr Hannay, a consultant dermatologist. Evidence for the defence was given by Dr Girdwood Ferguson, a consultant dermatologist. The pursuer described his symptoms at various times. I was not satisfied that the recollections of the pursuer in regard to the extent of his skin condition in early April 1967 were completely reliable. In his evidence, he stressed the dermatitic condition of his back at that time but, according to Dr Hannay, this back condition was not mentioned to him in the symptoms which the pursuer described to him in October 1967. Dr Hannay, who saw him not only in October 1967, when he was referred to him for treatment, but again in May 1968, when he examined him for national insurance purposes, said that it was on the latter occasion that the pursuer drew attention to his back condition for the first time. Dr Hannay thought that this condition was of no significance in regard to the cause of the disease. Dr Kerr, who also relied on his recollections, did refer to a back condition of acne which was non-active. I was not particularly impressed by the reliability of all of Dr Kerr's recollections of what he saw and was told early in April 1967. He did not have any written records to assist his memory. He said that the pursuer had told him that he had been having skin trouble for about two weeks prior to his examination on 4th or 5th April 1967, but Dr Kerr's letter, of October/November 1967, to the Edinburgh Royal Infirmary is inconsistent with that. In that letter, No. 17 of process, he said, inter alia :

"This man has had persistent dermatitis of arms and legs for 6/12 months—originally following temporary change of work."

The reference to "temporary change of work" is, I think, of importance in this connection.

In my opinion, the pursuer has established that he contracted the dermatitis in the course of his work in the brick kiln and as a result of the exposure to dust and ashes, when working there in the conditions which I have described. Dr Kerr thought so in April 1967 and has continued to be of the same view. Dr Hannay was of the same opinion on his two examinations and he gave cogent reasons for that opinion. Dr Ferguson did not see the pursuer until November 1968 and he saw him again in April 1971 in order to prepare for the proof. His opinion was based on what he saw then, including a condition of the scalp, which had not been seen by Dr Kerr or by Dr Hannay at any time. It is, I think, important that he agreed with the other two doctors that the conditions under which the pursuer worked in the brick kiln exposed him to the risk of occupational dermatitis. (See Gardiner v. Motherwell Machinery Co. , 1961 S.C. (H.L.) 1, at p. 17, per Lord Reid). He, furthermore, agreed with the other doctors that the exacerbation of the dermatitis when the pursuer returned to brick work with the defenders for a short period in March 1968 was of some significance in regard to ascertaining the cause of the disease. He did not dispute that the type and distribution of the lesions as found by Dr Hannay in November 1967 were consistent with an occupational dermatitis. It is, I think, important that there was no acceptable evidence that the pursuer had suffered from dermatitis prior to April 1967. Dr Ferguson and defenders' counsel placed great reliance on the pursuer's back condition. I do not think that such evidence as there was on this matter could indicate that the pursuer was, as Dr Ferguson suggested, a "strong seborrhoeic subject." This aspect was not really explored in the cross-examination of Dr Hannay. Dr Ferguson stressed that his view was based on what he saw in November 1968 and he agreed that Dr Hannay was "theoretically" in a better position to speak to the cause because of his earlier examinations. In all the circumstances I prefer Dr Hannay's evidence, supported by Dr Kerr, to that of Dr Ferguson and, as I have said, the pursuer succeeds on this aspect of his case.

The next question is whether the pursuer has established any fault or negligence by the defenders which caused or materially contributed to his contraction of dermatitis. In his written pleadings, the pursuer founds on the defenders' common law fault and negligence and on their breach of statutory duty. His counsel, in his closing address, conceded that the case on breach of statutory duty could not succeed. I agree and I say no more about that. He also conceded that the common law case, in so far as it was based on a failure in duty "to take reasonable care to ventilate the kiln effectively by drawing in cool air," could not succeed. I agree and I say no more about that. He maintained that the pursuer had established breaches of the two other particular duties averred in the common law case and that these breaches caused the pursuer to contract dermatitis or materially contributed to his contracting it. The first of these is in these terms, viz.:

"It was their duty to take reasonable care to see that the kiln had cooled sufficiently before sending men to work therein."

The other is in these terms, viz.:

"It was their duty to take reasonable care to provide adequate washing facilities including showers, soap and towels to enable men to remove dust from their bodies."

I consider the submissions by counsel on these two alleged breaches separately and in the order stated. I add that the inquiry was by a proof before answer and that the defenders' first plea-in-law is in these terms, viz.:

"The pursuer's averments being irrelevant et separatim being lacking in specification, the action should be dismissed."

This has some bearing on the averments relating to the said first alleged breach.

The basis of the submission by pursuer's counsel in regard to the first alleged breach was that, in the absence of averments or evidence by the defenders about their system, the court should draw favourable inferences from the evidence led for the pursuer ( O'Donnell v. Murdoch Mackenzie & Co. , 1967 S.C. (H.L.) 63, at p. 73, per Lord Wilberforce). There was, it was said, clear evidence, even from Dr Ferguson, that the conditions of heat and dust in which the pursuer had to work in the kiln at the material times exposed him to the risk of occupational dermatitis. The consequence of cooling by the fan was the blowing of dangerous dust on to skin which was softened by the heat sweat, with the resulting risk of dermatitis. Prior cooling, with or without the use of the fan, would have removed the risk in that the fan would not have been necessary when men were inside. There was evidence from the pursuer that there was nothing to stop the defenders leaving the bricks for a day or two longer, after being baked, and that rapid cooling would not affect the bricks. As I understood this submission, the words "cooled sufficiently" were meant to indicate that the inside of the chamber should have been so cooled, before men went in to remove bricks, that the use of the fan, which blew dangerous dust about, would not have been required when men were in the chamber and removing baked bricks. I am doubtful whether the averment gives that meaning with proper specification but I proceed on the basis that it does. The inference which I was asked to draw was that the defenders were at fault in sending men into a hot chamber to remove bricks at a time when the fan was required to be in operation to cool the inside of the chamber.

I do not think that I could draw that inference from the evidence which was led for the pursuer. Neither he nor John Herron suggested that it was practicable to reduce the heat in a chamber, from which bricks were being removed, so that a fan would not be required to blow cool air into that chamber. Neither of these witnesses suggested the length of time it would require to cool the inside of the chamber and the bricks there sufficiently to dispense with the fan, or even that it was possible to dispense with the fan altogether. Apart from the heat from the bricks, it was clear from the uncontradicted evidence that the fires heating other chambers contributed materially to the heat in the chamber from which the bricks were being removed. Whatever inferences I might draw from the uncontradicted evidence led for the pursuer, it seems to me to be going too far to draw the inference of fault which I was asked to draw. There was no evidence regarding the extent of cooling required and whether it was possible to reduce the heat in a chamber so that a fan was not required. There was, furthermore, no evidence about the consequences of the suggested extended cooling, especially if other chambers could not be used when one chamber was being emptied. The absence of any evidence as to practice in brick works did not assist the pursuer.

There was a suggestion in the submissions by pursuer's counsel that "cooled sufficiently" could mean, alternatively, a reduction in heat which would reduce the risk of dermatitis because a workman would sweat less and be less liable to have his skin injured by the dust or grit. There was medical evidence that a reduction in heat would lessen the risk but I do not think that this would assist the pursuer. The pursuer must establish, on a balance of probabilities, that "the breach of duty caused or materially contributed to his injury." ( Wardlaw v. Bonnington Castings , 1956 S.C. (H.L.) 26, at p. 31, per Lord Reid). The fact that the risk of contracting the disease might have been lessened to some unknown and unspecified extent, cannot mean that, on the probabilities, he would have escaped the disease. I refer to this again later in my comments on the second alleged breach of common law duty.

The submission by pursuer's counsel in regard to the second alleged breach was confined to the absence of shower baths. There were some differences between the pursuer and John Herron in regard to the number of basins and towels provided and there was some unsatisfactory evidence about the occasional absence of soap from the wash rooms. Pursuer's counsel did not rely on this unsatisfactory evidence. There was, it was agreed, a supply of hot and cold water.

There was no dispute that men employed at the brickworks had been able to use shower baths at the Prestongrange Colliery until the closing of the Colliery in 1963. The question is whether the defenders were at fault in failing to provide shower baths for men employed in the brick kilns thereafter. I think that, on the evidence, the defenders were at fault in this respect. Dr Hannay and Dr Ferguson both said that showers would reduce the risk of contracting the disease, the former using the word "materially." Dr Hannay went so far as to say that it was a usual precaution and that, from a medical point of view, he would advise it. There was no evidence from the defenders to counteract that evidence. It was said by defenders' counsel that Dr Hannay's evidence that the grit would come on exposed areas meant that the washing facilities provided by the defenders were enough, as exposed areas could be washed. I have two comments on that. Firstly, Dr Hannay was not cross-examined on his evidence that shower baths would reduce the risk and it was not suggested to him that only washing of exposed areas of the body was required for protection. Secondly, it seems clear that the pursuer's legs were affected by dermatitis at an early stage and it is not clear how a roller towel, which was described, could be used to wash legs. That aspect was not explored in the evidence. It was further said, by defenders' counsel, that there was no evidence about complaints regarding the absence of shower baths or about other men having contracted dermatitis. The fact that the pursuer, on return from work, had a bath in his own home, which was 10 or 15 minutes away from the brickworks, was said to be in the defenders' favour in failing to provide shower baths. I do not think that these matters can affect the conclusion which I have reached in regard to this ground of fault, on the evidence.

As I have maintained earlier, the pursuer, in order to succeed, must also establish, on a balance of probabilities, that this fault on the part of the defenders "caused or materially contributed to his injury," that is to his contracting dermatitis. Dr Hannay's evidence was that he could not say that the provision of showers would probably have prevented the disease. He said that it would have reduced the risk materially but he would not go further than that. Dr Ferguson said that washing reduces the risk. Pursuer's counsel maintained that a material increase in the risk of contracting a disease was the same as a material contribution to contracting the disease and that Dr Hannay established this by his evidence. I think that defenders' counsel was correct when he said that the distinction drawn by Dr Hannay was correct and that an increase in risk did not necessarily mean a material contribution to the contracting of the disease. The two concepts are entirely different. A material increase in risk may refer only to possibilities and may not make a possibility into a probability. It may strengthen the possibility but that cannot mean that in all such cases the possibility has become a probability. What the pursuer has to show is that, as he avers, he would not have contracted the disease but for the defenders' breach of duty. He has to show that this was probable and the degrees of risk have no relevance unless they make the contraction of the disease more probable than not contracting the disease. He cannot succeed if the only inference from the evidence is that lack of shower baths is a possibility as a cause of his having contracted the disease and that the provision of shower baths would have increased the possibility but not made it a probability. That is the only inference which I can draw from Dr Hannay's evidence and that was the best evidence for the pursuer. Causal connection between fault and the contraction of the disease has not been established.

For the reasons which I have given, the pursuer's case fails.

The pursuer reclaimed. On 17th March 1972 the First Division adhered to the interlocutor of the Lord Ordinary and refused the reclaiming motion.

LORD PRESIDENT (Clyde) .—This is a reclaiming motion by the pursuer in an action of damages at common law brought against his employers, the National Coal Board. He was employed by them at their brick works at Prestongrange where his duties involved him in helping other employees to remove bricks from the brick kilns there after they had been baked. It is not now disputed that while engaged in this work he contracted dermatitis. The issue in the case is whether or not he has established that his disease was caused by the fault and negligence of the defenders.

In view of the doubtful relevancy of the pursuer's averments of such fault as the cause of his disease, a proof before answer was allowed, and after hearing the evidence the Lord Ordinary reached the conclusion that the pursuer had not established a causal connection between the faults of the defenders which he averred and the dermatitis from which he suffered and the Lord Ordinary therefore assoilzied the defenders. Against his interlocutor so doing the pursuer has reclaimed. We have now heard the parties on the issue arising between them, which falls into a narrow compass.

As the facts surrounding the working of the kiln and the removal there-from of the baked bricks are clearly and succinctly set out by the Lord Ordinary—and no challenge of his findings on this matter was raised by either party before us—I do not find it necessary to rehearse the details of this aspect of the case. I turn therefore at once to the question in dispute between the parties—namely whether the Lord Ordinary was correct in holding on the evidence that the pursuer had not established that the breaches of duty alleged by him did cause the onset of the pursuer's dermatitis. The pursuer's case on this matter is that "the defenders failed in these duties and so caused his disease. Had the defenders fulfilled said duties incumbent on them the pursuer would not have contracted the said disease." (See condescendence 3.) This matter must be determined according to our law on a balance of probabilities as established by the evidence—a straightforward test which is very common in actions of damages at common law.

The breaches of duty alleged are two in number, and I shall deal with each in turn. The first breach alleged was a failure to provide adequate washing facilities, including showers, soap and towels, to enable men to remove sweat from their bodies, immediately after leaving the hot kiln. When this matter is put to the medical witnesses, although repeated opportunities are given to them, none of them will say that this breach of duty caused the disease. As Dr Hannay said (at p. 38) "even with the best possible procedure for removal of grit and sweat you would still have sufficient exposure (in working in the kiln) to create a liability for trouble. Q.—Are you in a position to say that if for example showers had been available at the place where Mr McGhee was working the skin condition which he developed would probably have been avoided? A.—I don't think anyone could positively say that that would have avoided the onset of the condition.…Nobody could say that that would prevent that man developing the condition."

There was no evidence to a contrary effect from any medical witness affirming a causal connection between the fault alleged and the onset of dermatitis. In these circumstances, in my opinion, the Lord Ordinary was well entitled to draw the conclusion on what was essentially a medical question that a breach of this duty was not proved to be the cause of the onset of the pursuer's dermatitis. He got it because he was working in a hot and dusty kiln, and there was nothing to show that it resulted from what he did or did not do when he left the heat inside the kiln and left the dust which he had encountered in the kiln. Indeed when he left the hot kiln and came outside he left behind the causes which made him liable to develop dermatitis.

Apart from the medical evidence which is destructive of any causal relation between the fault alleged and the injury sustained, it appears that there was, in any event, a very short space of time before he left the works and cycled home (a very short distance) where he could wash and change. It is difficult to accept the hypothesis that in that short space of time his skin could be affected, and there is no warrant at all in the evidence for inferring that this short interval before he washed off the dust could or did make any difference. In my opinion, therefore, there was ample warrant for the Lord Ordinary's conclusion on this first ground of fault alleged against the defenders. No-where in the evidence is there any suggestion that washing facilities were commonly or usually available for men immediately after leaving their work in unloading a kiln.

An analogy was sought to be made between a dermatitis case such as the present and the decisions of the court in pneumoconiosis cases. But this analogy is in my opinion a false one, and does not assist the pursuer. The issue between the parties in the present case is whether the pursuer's disease was caused by the defenders' failure to supply washing facilities at the brick works. This was not the issue in the pneumoconiosis cases. The complication in these latter cases was that the disease was created by the gradual accumulation of silica dust particles in the lung over a long period. Some of that dust was released into the atmosphere which the pursuer breathed owing to faulty machines or faulty ventilation, and some of it from machines which were not faulty. In these cases (e.g., Wardlaw v. Bonnington Castings , 1956 S.C. (H.L.) 26, see especially Lord Keith, at p. 36; Nicholson v. Atlas Steel Foundry and Engineering Co. , 1957 S.C. (H.L.) 44) there were two causes operating, one of which was an innocent one, and the other a guilty one. As the workman in fact developed pneumoconiosis from inhaling both the innocently produced silica dust and guiltily produced silica, dust, he was held entitled to recover damages unless it was shown that the contribution from the innocently caused dust was purely minimal. These cases are not, therefore concerned with whether the defenders' faulty equipment was a cause of the disease at all. That was established, and the issue in the cases arose on that basis. But in contrast to the pneumoconiosis cases, the present case is essentially concerned with proof of the causal connection between the fault alleged (i.e. inadequate washing facilities) and the development of dermatitis. Even if the pursuer had established (as he did not) that the absence of washing facilities increased the risk of the pursuer getting dermatitis, that would clearly not prove that the absence of these facilities caused the disease, nor indeed would it go any distance towards proving it. For risk of dermatitis and causation of dermatitis are two quite separate matters.

In the result, therefore, in my opinion, the Lord Ordinary reached the correct conclusion in regard to the question of washing facilities.

The only other ground of fault alleged is that the defenders failed to take reasonable care to see that the kiln had cooled sufficiently before sending men to work therein.

In the first place, however, there is no specification of what the word "sufficiently" means, and no evidence was led to cast any light on its meaning. In argument it was suggested that it means such a reduction in heat as to supersede the need for a fan to cool the air in the kiln when the men were removing the baked bricks, or that it means so cool that no one would sweat, or even that it means that the kiln should have been opened and left open till all the heat had gone. There is no warrant in my opinion for any of these interpretations. None of them are supported in evidence. The fact is that no one appears to have complained of the heat in the kiln when the workman went to empty it. There is no suggestion that any workman there had ever contracted dermatitis at this kiln or that a hot atmosphere caused dermatitis. In my opinion, upon this branch of the case the pursuer also fails. On the whole matter, in my opinion, the Lord Ordinary reached a sound conclusion and his interlocutor should be affirmed.

LORD MIGDALE .—This is a reclaiming motion from an interlocutor of the Lord Ordinary which assoilzied employers from a claim for damages by a workman based on alleged breaches of their duty to take reasonable care for his safety.

The pursuer was employed by the defenders at their Prestongrange Brickworks, Musselburgh, for several years before April 1967, in removing lengths of clay pipes which had been baked in kilns. He made no complaint of dermatitis or skin irritation.

In April 1967 he was put to work on removing newly baked bricks from a kiln. That kiln consisted of a long structure divided into two by a longitudinal central wall. Green bricks were stacked up in rectangular blocks. Each block or stack measured some 30 feet by 20 feet and was 10 feet high. At intervals there were doorways in the long sides. When the stack was assembled the doorway for that stack was bricked up and sealed. The stacks were dried by coal fires inside the kiln. Drying took about a week. At the end of that time an aperture was opened in the doorway and after a day or two the doorway was cleared, the end of a transporter was run in, and a fan was erected in the doorway to blow in cold air. After an interval workmen went inside the kiln, dismantled the stack and put the bricks on the conveyor to be loaded on to a lorry.

The pursuer says that when he went in the inside of the kiln was still very hot, which caused him to sweat profusely; that the kiln was filled with brick dust and coal ashes and that the fan blew the dust and coal ashes about so that he became covered in dust. As a result he developed a rash on his skin which has been diagnosed as post traumatic infective dermatitis. The medical evidence describes this as dermatitis resulting from infection from the skin started by abrasion which damages the outer protective layer. This came about because the heat caused him to sweat profusely and particles of dust stuck to his wet skin. Moreover, the sweat softened the skin and made it more likely to be attacked.

The pursuer originally laid his case on breach of common law and of statutory duty. This latter claim has been abandoned. His claim is now one based on breach of the defenders' common law duty to take reasonable care for his safety. There are two grounds of alleged failure of duty.

The first concerns the heat inside the kiln. The pursuer avers that the defenders "knew or ought to have known that their servants would be liable to develop skin conditions if they had to work in hot and dirty conditions in brick kilns. It was their duty to take reasonable care to see that the kiln had cooled sufficiently before sending him to work therein." The second concerns washing facilities—"It was their duty to take reasonable care to provide washing facilities, including showers, to enable men to remove dust from their bodies. In these duties they failed and so caused said disease. Had the defenders fulfilled said duties incumbent on them the pursuer would not have contracted said disease."

The Lord Ordinary held that the pursuer's averments about temperature and in particular the duty to see that the kiln had cooled sufficiently before sending him to work were vague and of doubtful relevancy. The pursuer asked him to read them as meaning that the kiln should be left to cool down so that a fan would not be needed to blow in air and stir up dust.

Before us counsel for the pursuer contended that these averments meant that workmen should not be allowed to enter the kiln until it was so cool that they would not sweat profusely. The Lord Ordinary has found against the pursuer on this fault and I see no reason to differ from his conclusion. There is no evidence in the case from which the court could determine whether it was reasonably practicable to reduce the temperature so as to avoid sweating or to dispense with the fan. There is no evidence of dermatitis having been contracted in the kilns and no averments about the practice in other brickworks.

The main contention concerned the defenders' failure to provide a shower for use after work. The Lord Ordinary held that they were in fault in this omission. He based his conclusion on the evidence of two dermatologists. Dr Hannay for the pursuer and Dr Ferguson for the defenders said that showers would reduce the risk of contracting the disease. Dr Hannay said a shower was a usual precaution and that from the medical point of view he would advise it.

The pursuer said that at the end of his work in the kiln he rode home on his bicycle and then had a bath and changed his clothes. The journey took 10 to 15 minutes. During that time he was no longer exposed to great heat and would not be sweating. On the other hand, his clothes would be damp with sweat and there would be dust on his skin and clothing. The question is whether the use of a shower at the brickworks and a change of clothing there (although he does not say this) would on a balance of probabilities have avoided dermatitis. This turns upon the evidence of the two doctors, who, on this point, appear to be in agreement.

Dr Hannay explained that the pursuer was suffering from post traumatic infective dermatitis, the result of exposure to a combination of considerable heat, which caused profuse sweating, and gritty dust. The sweating softened the outer layer of the skin and some dust would adhere to it. Friction would then grind the particles of dust on to the skin and cause abrasion of the normally hard outer layer. This would expose the tender cells below, causing irritation and dermatitis. The effect was due to a combination of extreme temperature and grit. "The one works hand in glove with the other." "If you reduce the temperature you reduce the stickiness of the skin and thereby reduce the adhesion of the grit."

In cross-examination he said that even with a shower you might have sufficient exposure in the kiln to cause injury. He was then asked—"Q.—If showers had been available the skin condition which he developed would probably have been avoided? A.—I don't think anybody can positively say that would have avoided the onset of the condition? Q.—Do I understand you to say you are not in a position to say that the provision of showers would probably have prevented his contracting this skin trouble? A.—No one could say that that would prevent that man developing the condition. It would be likely to reduce the chances." The Lord Ordinary then pointed out that the question contained the word "probably" and the doctor replied:

"I can only say it would reduce the chances. Q.—That is as far as you are able to go? A.—Yes."

In re-examination the doctor was asked about causation:

"Q.—Are you indicating that the longer one is exposed to the traumatic agent in such conditions the greater the risk of you suffering the kind of injury which leads to this condition? A.—Yes."

The doctor said that the removal of either the heat or the dust would materially reduce the risk. He agreed that the only practical measure was the provision of adequate washing facilities. The Lord Ordinary asked the doctor whether a shower would reduce the risk materially or to any great extent or something of that kind or only to a minor extent and his answer was "No, I think it fair to say materially. One cannot give a percentage figure for such things."

Dr Girdwood Ferguson for the defenders described the effect of heat, sweating and dust on the skin. He also agreed that risk of dermatitis could be materially reduced by removing the dust or reducing the temperature. He was asked:

"If he was given an opportunity to have a shower would that materially reduce the risk of skin injury?"

The answer was "yes."

As I read the evidence, once the man left the kiln the damaging factors of heat and dust would cease to operate. A shower would clean his skin and get rid of grit sticking to it but it would not repair the damage done. The doctors say a shower taken after work ended would materially reduce the risk of contracting dermatitis but neither will say, on a balance of probabilities, that it would do so.

Counsel for the pursuer contended that as it was now accepted that the failure to provide a shower was a breach of the duty which the defenders owed to the pursuer to take reasonable steps for his well-being, the doctors' evidence that it would have materially reduced the risk of dermatitis is enough to link the failure with the injury. Counsel for the defenders, on the other hand, contended that the test of causal connection between the breach and the injury is whether the provision of a shower would, on a balance of probabilities, have prevented the dermatitis. The Lord Ordinary says that an increase in risk does not mean a material contribution to the contracting of the disease. A material increase in risk may refer only to possibilities and it does not make a possibility into a probability. "What the pursuer has to show is that, as he avers, he would not have contracted the disease but for the breach of duty." He has to show this on a balance of probabilities.

In my opinion this is correct. Unless the pursuer can point to evidence that shows that a shower would more probably have avoided the disease than not, he cannot succeed and I do not find that evidence in this case.

Counsel for the pursuer sought to draw an analogy between the 15 minutes exposure to grit and damp clothes and the pneumoconiosis cases of Wardlaw v. Bonnington Castings , 1956 S.C. (H.L.) 26 and Nicholson v. Atlas Steel Foundry and Engineering Co. , 1957 S.C. (H.L.) 44. In Wardlaw dust inhaled in a dressing shop came from two sources. One was operating in breach of a duty on the employers: the other operated without breach of duty. It was impossible to say what proportion of dust inhaled by the victim came from each source. It was accepted that he inhaled dust from both sources. Both in the Court of Session and in the House of Lords it was held that the dust from the "liability" source materially contributed to the disease. Any contribution which was not minimal was a material contribution and the pursuer succeeded. At p. 31 Lord Reid said the employee must make it appear at least that on a balance of probabilities the breach of duty caused or materially contributed to his injury.

In the case of Nicholson the fault was in not having an adequate system for extracting dust. The pursuer could not avoid inhaling dust but as Viscount Simonds said (at p. 62) "It must be obvious that the sooner the dust … was dispersed the fewer particles he would inhale, and equally obvious that if there is no ventilation and no circulation of air the dispersal of [dust] will be delayed and the workman will remain in the concentration. … The question then is whether the respondents could have improved the ventilation by the method suggested." Lord Cohen (at p. 65) referred to the employer's failure to provide adequate ventilation and said that fact must increase the risk and Lord Keith (at p. 68) said that improved ventilation would have appreciably diminished the amount of dust inhaled.

In both these cases the noxious and illegal dust in the place of work contributed to the dust inhaled which in turn caused pneumoconiosis. In the present case the damage was done by the combination of two factors, excessive heat and dust, neither of which (on the view I take) was produced in breach of duty, and both of which operated only within the kiln. The only time during which the shower (the absence of which is the breach of duty) could have any effect was after the pursuer left the kiln and the source of the damage to his skin. A shower could not make good damage done in the kiln and the journey home would not create more heat or dust. It would no doubt remove particles of dust on his skin and lessen irritation but it could not obviate nor lessen the damage done inside the kiln.

At one time the duty on an employer was described as one to see that the workman was not exposed to any "unnecessary risk." Since the decision in English v. Wilsons and Clyde Coal Company Ltd. , 1937 S.C. (H.L.) 46, it is usually described as a duty "to take reasonable care for the safety of the employee." A practical way to test it is to ask whether, if an employer had used the device he is told he should have used, this would have avoided the injury, and the standard is the balance of probabilities. If an employer was required to use every precaution which might diminish the risk there would be no end to the steps he would have to take.

On the whole matter I think the Lord Ordinary arrived at the right decision and I refuse the reclaiming motion and assoilzie the defenders.

LORD JOHNSTON .—There is little doubt about the facts out of which this claim for damages arises. For about 15 years prior to April 1967 the pursuer and reclaimer, whom I shall refer to as the "workman," was employed by the defenders and respondents, the National Coal Board, at the pipe kilns at Prestongrange Brickworks, Musselburgh. About 30th March 1967 he was sent to work temporarily at a brick kiln and he continued at that work until 4th April 1967 when he gave up work because of a dermatitic condition which he developed. In their pleadings the Board aver that the skin disease from which the workman suffered was of a non-occupational character and led evidence to support that averment. The Lord Ordinary has found that the workman contracted the dermatitis in the course of his work in the brick kilns and as a result of exposure to dust and ashes when working there in very hot conditions. That finding was not challenged before us. The only issue in the case now is, whether the workman has established that the dermatitis was caused by the fault of the Board.

The workman avers that the Board knew or ought to have known that workmen would be liable to develop skin conditions if they had to work in hot and dirty conditions in brick kilns and that in these circumstances it was their duty "to take reasonable care to see that the kiln had cooled sufficiently before sending men to work therein"; and to provide adequate washing facilities including showers, soap and towels to enable men to remove dust from their bodies; and that if the Board had fulfilled their duties the workman would not have contracted the disease.

The evidence relating to the Board's knowledge of the effect of requiring workmen to work in hot and dirty conditions is not entirely satisfactory. There is no evidence that any of the other workmen working in the brick kiln or in similar kilns, ever contracted dermatitis and indeed the only evidence from which the Board's knowledge might be inferred is the evidence of Dr Hannay that occupational dermatitis occurs among miners, bricklayers, and brickmakers and of Dr Ferguson, their expert medical witness, that it is fairly well known that occupational dermatitis arises from exposure to dust and heat. The evidence is, I think, sufficient, but only just sufficient, to establish that the Board knew or ought to have known that the workman's condition of employment was such that he ran the risk of contracting dermatitis.

The first suggested precaution was—"to see that the kilns had cooled sufficiently before sending men to work therein." "Sufficiently" was never defined but, as I understood the submission, what was sought was that the temperature should be such as to render the fan unnecessary to prevent workmen sweating before they were required to enter the kiln. The Lord Ordinary has reviewed the evidence, or rather lack of evidence, relating to this ground of fault. It is sufficient to state that it appears that the only way to achieve the condition suggested was to draw the fires and open up a number of doors in the kiln for an extended period. The absence of evidence that other workmen in the brickmaking kiln had contracted the disease suggests that such a precaution would, or at least might be, out of all proportion to the risk. In these circumstances, I agree that the failure to take such steps did not amount to a neglect to take a reasonable precaution.

The second ground of fault is that the Board had failed to provide showers for brickworkers since 1963 when the showers at Prestongrange Colliery were closed. Dr Hannay and Dr Ferguson agreed that if showers had been provided and the workman had made use of them the risk of the workman contracting dermatitis would have been reduced. They were pressed to express themselves in more definite terms. Dr Hannay said that he did not think that anyone could positively say the provision and use of showers would have avoided the onset of the condition. He was pressed to state whether their provision would "probably" have prevented the contraction of the disease and he replied—"I can only reply that it would reduce the chances." He stated later that he would advise that men should be provided with showers, that the provision of showers is an accepted measure worth using and would have reduced the risk "materially." Dr Ferguson stated that their provision would have reduced the risk "materially."

Your Lordships and the Lord Ordinary have reached the conclusion that the medical evidence to which I have referred does not establish on a balance of probability that the provision of showers would have prevented the workman contracting dermatitis. In my opinion the evidence is on a nice balance, but in view of your Lordships' opinions I do not feel inclined to take the view that the evidence is sufficient to allow me to hold that the test of the balance of probability has been satisfied. Accordingly, I concur in your Lordships' view that the reclaiming motion should be refused.

The pursuer appealed to the House of Lords, and the case was heard on 8th and 9th October 1972.

At delivering judgment on 15th November 1972,—

LORD REID .—My Lords, the appellant was employed for many years by the respondents as a labourer at their Prestongrange Brickworks. His normal work was emptying pipe kilns. On 30th March 1967 (a Thursday), he was sent to empty brick kilns. Working conditions there were much hotter and dustier than in the pipe kilns. On Sunday, 2nd April, he felt extensive irritation of his skin. He continued to work on the Monday and Tuesday and then went to his doctor who put him off work and later sent him to a skin specialist. He was found to be suffering from dermatitis.

He sued the respondents for damages alleging breaches on their part of common law duties to him. After proof before answer the Lord Ordinary assoilzied the respondents. On 17th March 1972 the First Division refused a reclaiming motion.

It is now admitted that the dermatitis was attributable to the work which the appellant did in the brick kilns. The first ground of fault alleged against the respondents is that the kilns ought to have been allowed to cool "sufficiently" before the appellant was sent to remove the bricks from them. I agree with the Scottish Courts that this contention fails; the pleading lacks specification and the evidence is much too vague to prove any breach of duty.

The other ground of fault alleged raises a difficult question of law. It is said in condescendence 3:

"It was their duty to take reasonable care to provide adequate washing facilities including showers, soap and towels to enable men to remove dust from their bodies. In each and all of said duties the defendant failed and so caused said disease. Had the defenders fulfilled said duties incumbent on them the pursuer would not have contracted said disease."

Originally the defence was twofold:(i) a denial of any such duty, and

(ii) an argument that the disease was of a non-occupational character. But the Lord Ordinary decided against the respondents in both of these matters and the respondents accept these findings. So the respondents' defence in the Inner House and before your Lordships has taken the unusual form that breach of duty is admitted, and that it is admitted that the disease is attributable to the work which the appellant performed in the brick kiln, but that it has not been proved that failure to carry out the admitted duty caused the onset of the disease.

The medical witnesses are in substantial agreement. Dermatitis can be caused, and this dermatitis was caused, by repeated minute abrasion of the outer horny layer of the skin followed by some injury to or change in the underlying cells, the precise nature of which has not yet been discovered by medical science. If a man sweats profusely for a considerable time the outer layer of his skin is softened and easily injured. If he is then working in a cloud of abrasive brick dust, as this man was, the particles of dust will adhere to his skin in considerable quantity and exertion will cause them to injure the horny layer and expose to injury or infection the tender cells below. Then in some way not yet understood dermatitis may result.

If the skin is not thoroughly washed as soon as the man ceases work that process can continue at least for some considerable time. This man had to continue exerting himself after work by bicycling home while still caked with sweat and grime, so he would be liable to further injury until he could wash himself thoroughly. Washing is the only practicable method of removing the danger of further injury.

The effect of such abrasion of the skin is cumulative in the sense that the longer a subject is exposed to injury the greater the chance of his developing dermatitis: it is for that reason that immediate washing is well recognised as a proper precaution.

I have said that the man began working in hot and dusty conditions on the Thursday. It appears to be accepted that his work on the Thursday, Friday and Saturday, together with the fact that in these three days he had to go home unwashed, was sufficient to account for his condition on the Sunday, and that this together with what he did on the Monday and Tuesday caused the onset of dermatitis.

It was held in the Court of Session that the appellant had to prove that his additional exposure to injury caused by his having to bicycle home unwashed caused the disease in the sense that it was more probable than not that this additional exposure to injury was the cause of it. I do not think that that is the proper approach. The Court of Session may have been misled by the inadequacy of the appellant's pleadings. But I do not think that it is now too late to re-examine the whole position.

It has always been the law that a pursuer succeeds if he can shew that fault of the defender caused or materially contributed to his injury. There may have been two separate causes but it is enough if one of the causes arose from fault of the defender. The pursuer does not have to prove that this cause would of itself have been enough to cause him injury. That is well illustrated by the decision of this House in Wardlaw v. Bonnington Castings . There the pursuer's disease was caused by an accumulation of noxious dust in his lungs. The dust which he had inhaled over a period came from two sources. The defenders were not responsible for one source but they could and ought to have prevented the other. The dust from the latter source was not in itself sufficient to cause the disease but the pursuer succeeded because it made a material contribution to his injury.

The respondents seek to distinguish Wardlaw's case by arguing that then it was proved that every particle of dust inhaled played its part in causing the onset of the disease whereas in this case it is not proved that every minor abrasion played its part.

In the present case the evidence does not shew—perhaps no one knows—just how dermatitis of this type begins. It suggests to me that there are two possible ways. It may be that an accumulation of minor abrasions of the horny layer of the skin is a necessary precondition for the onset of the disease. Or it may be that the disease starts at one particular abrasion and then spreads, so that multiplication of abrasions merely increase the number of places where the disease can start and in that way increases the risk of its occurrence.

I am inclined to think that the evidence points to the former view. But in a field where so little appears to be known with certainty I could not say that that is proved. If it were then this case would be indistinguishable from Wardlaw's case. But I think that in cases like this we must take a broader view of causation. The medical evidence is to the effect that the fact that the man had to cycle home caked with grime and sweat added materially to the risk that this disease might develop. It does not and could not explain just why that is so. But experience shows that it is so. Plainly that must be because what happens while the man remains unwashed can have a causative effect, though just how the cause operates is uncertain. I cannot accept the view expressed in the Inner House that once the man left the brick kiln he left behind the causes which made him liable to develop dermatitis. That seems to me quite inconsistent with a proper interpretation of the medical evidence. Nor can I accept the distinction drawn by the Lord Ordinary between materially increasing the risk that the disease will occur and making a material contribution to its occurrence.

There may be some logical ground for such a distinction where our knowledge of all the material factors is complete. But it has often been said that the legal concept of causation is not based on logic or philosophy. It is based on the practical way in which the ordinary man's mind works in the every-day affairs of life. From a broad and practical viewpoint I can see no substantial difference between saying that what the defender did materially increased the risk of injury to the pursuer and saying that what the defender did made a material contribution to his injury.

I would therefore allow this appeal.

LORD WILBERFORCE .—My Lords, my noble and learned friend, Lord Reid; has explained the circumstances in which, as the relevant claim in this appeal, the appellant claims damages at common law in respect of his employers' fault in failing to provide adequate washing facilities so as to remove the dust from his body before he left the place of work.

The Lord Ordinary, while finding that the respondents were at fault in not providing shower baths for their men who, like the appellant, worked under hot and dusty conditions in the kilns, yet dismissed the appellant's claim because he was not satisfied that the appellant had shown, on the balance of probabilities, that this breach of duty caused or materially contributed to his injury. This reasoning was approved by the First Division. In order to evaluate it, it is necessary to amplify the findings and inferences.

In the first place, the holding that there was a breach of duty by the respondents was founded upon the evidence of the appellant's medical expert that washing by shower baths is the only method of any practical use by which the risk of dermatitis, in the relevant conditions, can be reduced. Possibly damaging agents, the doctor said, should be removed as soon as possible: washing is standard practice in all industrial medicine. The respondents must, from their experience with occupations involving the production of dust, have been aware of this, and as one would expect, there were showers available at the nearby Prestongrange Colliery which men on the kilns could use until the Colliery was closed in 1963. There was, therefore, a solid basis for a finding that showers ought to have been provided. It was inherent in this finding that the employers should have foreseen that, unless showers were available at the place of work, there would be an increased risk of dermatitis occurring.

But it was not enough for the appellant to establish a duty or a breach of it. To succeed in his claim he had to satisfy the Court that a causal connection existed between the default and the disease complained of, i.e. , according to the formula normally used, that the breach of duty caused or materially contributed to the injury. Here two difficulties arose. In the first place, little is known as to the exact causes of dermatitis. The experts could say that it tends to be caused by a breakdown of the layer of heavy skin covering the nerve ends provoked by friction caused by dust, but had to admit that they knew little of the quantity of dust or the time of exposure necessary to cause a critical change. Secondly, there could be little doubt that the appellant's dermatitis resulted from a combination, or accumulation, of two causes: exposure to dust while working in hot conditions in the kiln and the subsequent omission to wash thoroughly before leaving the place of work; the second of these, but not the first, was, on the findings, attributable to the fault of the respondents. The appellant's expert was unable to attribute the injury to the second of these causes for he could not say that if the appellant had been able to wash off the dust by showers he would not have contracted the disease. He could not do more than say that the failure to provide showers materially increased the chance, or risk, that dermatitis might set in.

My Lords,

I agree with the judge below to the extent that merely to show that a breach of duty increases the risk of harm is not, in abstracto , enough to enable the pursuer to succeed. He might, on this basis, still be met by successful defences. Thus, it was open to the respondents, while admitting, or being unable to contest, that their failure had increased the risk, to prove, if they could, as they tried to do, that the appellant's dermatitis was "non-occupational."

But the question remains whether a pursuer must necessarily fail if, after he has shown a breach of duty, involving an increase of risk of disease, he cannot positively prove that this increase of risk caused or materially contributed to the disease while his employers cannot positively prove the contrary. In this intermediate case there is an appearance of logic in the view that the pursuer, on whom the onus lies, should fail—a logic which dictated the judgments below. The question is whether we should be satisfied in factual situations like the present, with this logical approach. In my opinion, there are further considerations of importance. First, it is a sound principle that where a person has, by breach of a duty of care, created a risk, and injury occurs within the area of that risk, the loss should be borne by him unless he shows that it had some other cause. Secondly, from the evidential point of view, one may ask, why should a man who is able to show that his employer should have taken certain precautions, because without them there is a risk, or an added risk, of injury or disease, and who in fact sustains exactly that injury or disease, have to assume the burden of proving more: namely, that it was the addition to the risk, caused by the breach of duty, which caused or materially contributed to the injury? In many cases, of which the present is typical, this is impossible to prove, just because honest medical opinion cannot segregate the causes of an illness between compound causes. And if one asks which of the parties, the workman or the employers should suffer from this inherent evidential difficulty, the answer as a matter in policy or justice should be that it is the creator of the risk who, ex hypothesi must be taken to have foreseen the possibility of damage, who should bear its consequences.

There are analogies in this field of industrial disease. In cases concerned with pneumoconiosis, the courts faced with a similar, though not identical, evidential gap, have bridged it by having regard to the risk situation of the pursuer. Pneumoconiosis being a disease brought on by cumulative exposure to dust particles, the courts have held that where the exposure was to a compound aggregate of "faulty" particles and "innocent" particles, the workman should recover, so long as the addition of the "faulty" particles ( i.e. , those produced by some fault of the employers) was material, which I take to mean substantial, or not negligible ( Wardlaw v. Bonnington Castings , Nicholson v. Atlas Steel Foundry and Engineering Co. Wardlaw's case was decided with full acceptance of the principle that a pursuer must prove not only negligence but also that such fault caused or materially contributed to his injury (per Lord Reid, at p. 31) and the pursuer succeeded because negligently-produced dust made a material contribution to the total dust which injured him. I quote from the opinion of Lord Keith:

"It was the atmosphere inhaled by the pursuer that caused his illness and it is impossible, in my opinion, to resolve the components of that atmosphere into particles caused by the fault of the defenders and particles not caused by the fault of the defenders, as if they were separate and independent factors in his illness. Prima facie the particles inhaled are acting cumulatively, and I think the natural inference is that had it not been for the cumulative effect the pursuer would not have developed pneumoconiosis when he did and might not have developed it at all."

The evidential gap which undoubtedly existed there ( i.e. the absence of proof that but for the addition of the "guilty" dust the disease would not have been contracted) is similar to that in the present case and is expressed to be overcome by inference.

In Nicholson's case, the pursuer was similarly affected by an indivisible aggregate of silica dust. He succeeded because (I quote from the opinion of Viscount Simonds) "owing to the default of the respondents the deceased was exposed to a greater degree of risk than he should have been"—the excess not being negligible, and according to Lord Cohen because the respondents' default had materially increased the risk and so, on a balance of probabilities, caused or materially contributed to his injury.

The present factual situation has its differences: the default here consisted not in adding a material quantity to the accumulation of injurious particles but by failure to take a step which materially increased the risk that the dust already present would cause injury. And I must say that, at least in the present case, to bridge the evidential gap by inference seems to me something of a fiction, since it was precisely this inference which the medical expert declined to make. But I find in the cases quoted an analogy which suggests the conclusion that, in the absence of proof that the culpable addition had, in the result, no effect, the employers should be liable for an injury, squarely within the risk which they created and that they, not the pursuer, should suffer the consequence of the impossibility, foreseeably inherent in the nature of his injury, of segregating the precise consequence of their default.

I would allow this appeal.

LORD SIMON OF GLAISDALE .—My Lords, I beg to take advantage of the narrative history and the summary of the medical evidence given by my noble and learned friend, Lord Reid, whose speech I have had the advantage of reading in draft. For the reasons which he gives I agree that the appellant failed to establish the first breach of common law duty alleged. I desire only to add some observations on the alleged breach of duty to provide adequate washing facilities.

The Lord Ordinary held that such a breach of duty was established. He held, however, that there was not established a sufficient causative connection between that breach of duty by the respondents and the appellant's injury. The medical evidence showed that the fulfilment of what was held to be the respondents' common law duty to provide adequate washing facilities would, if they had been used (and the appellant had used shower baths immediately after work when they had been available in earlier years), have materially reduced the risk of dermatitis. Neither consultant would, however, go so far as to say that washing after work would have made it more probable than not that the appellant would have escaped dermatitis. The consultant called for the appellant averred, indeed, that no one could say such a thing—implying that no doctor could, in the present state of medical knowledge, make such an assertion in any circumstances. The Lord Ordinary held that the appellant, to succeed, had to prove a causative connection between the respondents' breach of duty and his own injury and that this involved proving that it was more likely than not that what had caused the appellant's injury was the respondents' breach of duty. Merely to show that compliance with that duty would have materially reduced the risk of injury was insufficient: it was necessary to go further, and show that such compliance would on a balance of probabilities have avoided the injury. The First Division upheld these findings of the Lord Ordinary.

But Wardlaw v. Bonnington Castings and Nicholson v. Atlas Steel Foundry & Engineering Co. establish, in my view that where an injury is caused by two (or more) factors operating cumulatively, one (or more) of which factors is a breach of duty and one (or more) is not so, in such a way that it is impossible to ascertain the proportion in which the factors were effective in producing the injury or which factor was decisive, the law does not require a pursuer or plaintiff to prove the impossible, but holds that he is entitled to damages for the injury if he proves on a balance of probabilities that the breach or breaches of duty contributed substantially to causing the injury. If such factors so operate cumulatively, it is, in my judgment, immaterial whether they do so concurrently or successively.

The question, then, is whether on the evidence the appellant brought himself within this rule. In my view, a failure to take steps which would bring about a material reduction of the risk involves, in this type of case, a substantial contribution to the injury. In this type of case a stark distinction between breach of duty and causation is unreal. If the provision of shower baths was (as the evidence showed) a precaution which any reasonable employer in the respondents' position would take, it means that such employer should have foreseen that failure to take the precaution would, more probably than not, substantially contribute towards injury: this is sufficient prima facie evidence. That "material reduction of the risk" and "substantial contribution to the injury" are mirror concepts in this type of case appears also from Lord Simonds' speech in Nicholson at pp. 62 and 63, where he was applying the concept of "substantial contribution" laid down in Wardlaw :

"…it was practicable for the respondents to have reduced the risk … It follows that owing to the default of the respondents the deceased was exposed to a greater degree of risk than he should have been, and, though it is impossible even approximately to quantify the particles which he must in any event have inhaled and those which he inhaled but need not have, I cannot regard the excess as something so negligible that the maxim ‘de minimis’ is applicable."

See also Lord Kilbrandon, Lord Ordinary, in Gardiner v. Motherwell Machinery & Scrap Co. , a dermatitis case, where at p. 3 he rehearsed the pursuer's argument, which he accepted, as follows:

"…that the washing facilities which were provided were inadequate and primitive, and that, if they had been up to standard, the risk of dermatitis would have been very much reduced."

His judgment was upheld in your Lordships' House, the headnote stating:

"…where a workman who had not previously suffered from a disease contracted that disease after being subjected to conditions likely to cause it, and showed that it started in a way typical of disease caused by such conditions, he established a prima facie presumption that his disease was caused by those conditions; and that, since, in the present case, the employers had failed to displace the presumption, they were liable to the workman in damages at common law."

To hold otherwise would mean that the respondents were under a legal duty which they could, in the present state of medical knowledge, with impunity ignore.

I would therefore allow the appeal.

LORD KILBRANDON .—My Lords, the facts relating to the nature and conditions of the pursuer's work, to the facilities provided by the defenders, and to the pursuer's having contracted an industrial dermatitis in consequence of those conditions of work, are undisputed. Medical science has, however, not yet been able to provide an indubitable account of how those conditions actually give rise to that disease, although the fact of causation is, according to the evidence in this case, unanimously accepted. Thus, of two men exposed to the same conditions, and taking the same precautions both during exposure to the condition and after having ceased to be exposed, one will get dermatitis and the other will not. A post-exposure precaution desiderated is the shower bath. As it was put to, and accepted by, the consultant physician giving evidence for the defenders, assuming that a workman had to work in a hot atmosphere and exposed to the risk of ash and dust over his working day, if he was given the opportunity to have a shower, and in fact took the shower that would materially reduce the risk to that man's skin of injury from those working conditions. It was for this reason that the Court of Session has held that it was the duty of the defenders, which they failed to carry out, to supply the pursuer with facilities for taking a shower after he had finished work. That can only be because knowledge must be imputed to the defenders that if the pursuer's body were to continue to be exposed to the dirt and sweat, inevitably attendant on his conditions of work, which were operating on him after he had finished work—being the only dirt and sweat that a shower could have removed—it was more probable that he would contract the disease than if no shower had been taken. It is, in the present state of medical knowledge, impossible to say that if the pursuer had taken a shower he would certainly not have got the disease, and it is equally impossible to say that another man, in exactly the same case as the pursuer, would on the contrary certainly have got it.

In that state of facts, what the pursuer has to establish, as a condition of his substantiating a claim against the defenders, is that their admitted breach of the duty which they owed to him caused or materially contributed to the damage which he has suffered. He has proved that there was a precaution, neglected by the defenders, which, if adopted by them, as their duty in law demanded, would have made it less likely that he would have suffered that damage. The argument against him as I follow it, is that that only shows that the provision of a shower bath would have reduced the risk of injury: it does not show that in his case he would more probably not have contracted the disease had the bath been provided.

It would have been possible to state the argument in this way:

"The pursuer cannot show that it is more probable than not that, if a shower had been provided, he as an individual would not have contracted dermatitis. Therefore it is impossible to say that the defenders were under a duty to him as an individual to supply a shower; A cannot have owed to B a duty to take a precaution the absence of which B fails to show probably caused him injury."

The duty can only be examined in relation to the individual who complains of the breach of it; it is not owed to him as a mere potential victim of dermatitis; and this is unaffected by the fact that other men, for reasons we do not understand, would not have required the benefit of the precaution.

But once the breach of duty to the pursuer has been accepted, this argument seems to me to become untenable. It depends on drawing a distinction between the possibility and the probability of the efficacy of the precautions. I do not find it easy to say in the abstract where one shades into the other; it seems to me to depend very much upon the nature of the case. This is a case in which the actual chain of events in the man's body leading up to the injury is not clearly known. But there are effective precautions which ought to be taken in order to prevent it. When you find it proved ( a ) that the defenders knew that to take the precaution reduces the risk, chance, possibility or probability of the contracting of a disease, ( b ) that the precaution has not been taken, and ( c ) that the disease has supervened, it is difficult to see how those defenders can demand more by way of proof of the probability that the failure caused or contributed to the physical breakdown. In other classes of case such a defence could more easily be established. An example of facts which could give rise to the defence was seen recently by your Lordships— Gibson v. British Insulated Callenders' Construction Co. Ltd. Suppose it to be the duty of employers in certain circumstances to supply safety-belts. They do not do so, and an employee is injured in a way which would not have happened if the belt had not been provided. But he cannot prove that the failure to provide it contributed to the accident, because it is certain that if it had been provided he would not have used it. In the present case, the pursuer's body was vulnerable, while he was bicycling home, to the dirt which had been deposited on it during his working hours. It would not have been if he had had a shower. If showers had been provided he would have used them. It is admittedly more probable that disease will be contracted if a shower is not taken. In these circumstances I cannot accept the argument that nevertheless it is not more probable than not that, if the duty to provide a shower had been neglected, he would not have contracted the disease. The pursuer has after all, only to satisfy the court of a probability, not to demonstrate an irrefragable chain of causation, which in a case of dermatitis, in the present state of medical knowledge, he could probably never do.

I agree with the Court of Session that the pursuer's case, in so far as it relates to the actual conditions of work, fails, but in my opinion he has succeeded in showing that his injury was, more probably than not, caused by or contributed to by the defenders' failure to provide a shower bath. I would therefore allow this appeal.

LORD SALMON .—My Lords, all the relevant facts, and the medical evidence about which there is no dispute, are fully set out in the speech of my noble and learned friend, Lord Reid. It is apparent that the hot and dusty conditions under which the pursuer was required to work exposed him to a serious risk of contracting dermatitis. The fact, however, that the defenders required the pursuer to work under these conditions has not been shown to constitute negligence on their part. On the other hand, it has been proved that in the circumstances any prudent employers would have provided adequate washing facilities for their employees. It is well recognised that shower baths should be available for employees to use immediately after finishing work of the kind upon which the pursuer was engaged. Such facilities would materially reduce the risk of contracting dermatitis. The defenders failed to supply shower baths or any other proper washing facilities. It is conceded that this failure on the part of the defenders did constitute negligence.

The pursuer contracted dermatitis. The question is: was the dermatitis proved to have been caused or materially contributed to by the defenders' negligence? The Court of Session answered this question in the defenders' favour on the ground that although the uncontradicted medical evidence established that adequate washing facilities would have materially reduced the risk it was impossible in the present state of medical knowledge to say that they would probably have prevented the pursuer from contracting dermatitis. The medical witnesses could not say that it was more likely than not that these precautions which reasonably careful employers should have taken would have prevented injury but only that such precautions would have materially reduced the risk of injury. The Lord Ordinary concluded that materially to increase the risk of injury does not amount to causing or materially contributing to the injury and that accordingly on a balance of probabilities no causal connection had been established between the defenders' negligence and the pursuers' injury. He, therefore, assoilzied the defenders. The Inner House upheld this decision largely for the same reasons as those given by the Lord Ordinary. The Lord President, however, in the course of his judgment, said:

"Even if the pursuer had established (as he did not) that the absence of washing facilities increased the risk of the pursuer getting dermatitis, that would clearly not prove that the absence of these facilities caused the disease, nor indeed would it go any distance towards proving it."

The first part of this passage, with all respect, seems to be based on a misunderstanding of the undisputed medical evidence. Nor can I accept the second part of the passage if the Lord President meant that in the circumstances of this case materially to increase the risk of injury was not a cause of the injury.

I, of course, accept that the burden rests upon the pursuer to prove, on a balance of probabilities, a casual connection between his injury and the defenders' negligence. It is not necessary, however, to prove that the defenders' negligence was the only cause of injury. A factor, by itself, may not be sufficient to cause injury but if, with other factors, it materially contributes to causing injury, it is clearly a cause of injury. Everything in the present case depends upon what constitutes a cause. I venture to repeat what I said in Alphacell Ltd. v. Woodward :

"The nature of causation has been discussed by many eminent philosophers and also by a number of learned judges in the past. I consider, however, that what or who has caused a certain event to occur is essentially a practical question of fact which can best be answered by ordinary commonsense rather than abstract metaphysical theory."

In the circumstances of the present case it seems to me unrealistic and contrary to ordinary commonsense to hold that the negligence which materially increased the risk of injury did not materially contribute to causing the injury.

Dr Hannay, an eminent dermatologist, made it plain in his evidence that medical knowledge relating to dermatitis was not yet very far advanced. He was asked: Q .—"Can you explain a little more fully the mechanics of it, how the condition occurs in such a situation?" A .—"As far as medical knowledge can help, yes. We have a lot to learn unfortunately, yet … what that reaction" (reaction of damage to the layers of the skin) "precisely is or how it occurs we do not know. We know what may cause it" (dermatitis) "but the reaction, the mechanism, we don't know …" When he said that the lack of washing facilities materially increased the risk of contracting dermatitis he added:

"One cannot give a percentage figure for such things."

It is known that some factors materially increase the risk and others materially decrease it. Some no doubt are periphery. Suppose, however, it were otherwise and it could be proved that men engaged in a particular industrial process would be exposed to a 52 per cent, risk of contracting dermatitis even when proper washing facilities were provided. Suppose it could also be proved that that risk would be increased to, say, 90 per cent when such facilities were not provided. It would follow that if the decision appealed from is right, an employer who negligently failed to provide the proper facilities would escape from any liability to an employee who contracted dermatitis notwithstanding that the employers had increased the risk from 52 per cent to 90 per cent. The negligence would not be a cause of the dermatitis because even with proper washing facilities, i.e. without the negligence, it would still have been more likely than not that the employee would have contracted the disease—the risk of injury then being 52 per cent. If, however, you substitute 48 per cent for 52 per cent the employer could not escape liability, not even if he had increased the risk to, say, only 60 per cent. Clearly such results would not make sense; nor would they, in my view, accord with the common law.

I think that the approach by the courts below confuses the balance of probability test with the nature of causation. Moreover, it would mean that in the present state of medical knowledge and in circumstances such as these (which are by no means uncommon) an employer would be permitted by the law to disregard with impunity his duty to take reasonable care for the safety of his employees.

My Lords,

I would suggest that the true view is that, as a rule, when it is proved, on a balance of probabilities, that an employer has been negligent and that his negligence has materially increased the risk of his employee contracting an industrial disease, then he is liable in damages to that employee if he contracts the disease notwithstanding that the employer is not responsible for other factors which have materially contributed to the disease. Wardlaw v. Bonnington Castings and Nicholson v. Atlas Steel Foundry and Engineering Co. I do not find the attempts to distinguish those authorities from the present case at all convincing.

In the circumstances of the present case, the possibility of a distinction existing between(a) having materially increased the risk of contracting the disease, and

(b) having materially contributed to causing the disease may no doubt be a fruitful source of interesting academic discussions between students of philosophy. Such a distinction is, however, far too unreal to be recognised by the common law. I would accordingly allow the appeal.