Outer House splits liability for asbestos damages between two employers by nearly 99.9 to 0.1 percent ratio

About this case:

• Citation:
  [2026] CSOH 34
• Judgment:
  External link
• Court:
  Court of Session Outer House
• Judge:
  Lord Harrower

Pursuer John Reid was formerly employed by MCM Building & Civil Engineering Construction Ltd and later by Pyramid Joinery & Construction Ltd on various construction projects between 1999 and 2003. Each defender admitted that it ought to have known about the risk of asbestos dust exposure, with the proof restricted to the question of liability.

The case was heard by Lord Harrower in the Outer House of the Court of Session, with C Wilson KC and Mutapi, advocate, appearing for the pursuer, McNaughtan KC and Rolfe, advocate, for the first defender, and N MacKenzie KC and D Blair, advocate, for the second defender.

1.5 and 720 days

In the summer of 2024 the pursuer, now aged 53, was diagnosed with pleural mesothelioma. It was admitted that the first defender was involved in general construction and civil engineering works, and that the pursuer was employed by it during the tax year 1999/2000. It was further admitted that the second defender carried out window and door replacement work for local authorities, and that the pursuer was employed by it between the tax years 2000/2001 and 2002/2003.

The pursuer recalled in his evidence that during his employment with the first defender he worked on a week-long project in Glasgow removing corrugated asbestos roofing from a row of four concrete garages, which required him to break them with a hammer. The broken material created a dusty atmosphere in the garage, which mostly subsided after the first day when he started installing the new roof.

During his work with the second defender, the pursuer was primarily involved in transporting material and tidying sites, including sorting asbestos waste from general waste by picking it out by hand without any protective clothing or respiratory equipment. He did this sort of activity on a daily basis. After he left the second defender’s employ, he was not further exposed to asbestos and left the workforce in 2010 to become a full-time carer for his partner.

On behalf of the first defender, it was submitted that the pursuer had failed to prove any facts beyond those established in the joint minute. In the event that exposure was proven, the relative lengths of exposure for which the defenders were responsible were 1.5 days and 720 days respectively, assuming the pursuer worked for the second defender for 5 days a week, 48 weeks a year, for 3 years. The second defender similarly submitted that liability had not been proven against them, and if apportionment were required their contribution should be assessed as nil.

Both defenders contributed

In his decision, Lord Harrower said of the reliability of the pursuer’s evidence: “I have no doubt that the pursuer would struggle to recall every last piece of asbestos he removed to skip, or every last job in which he and his colleagues had been engaged. But as Lord Leggatt observed in Gestmin SGPS SA v Credit Suisse UK Ltd (2013), the value of oral testimony lies in the opportunity which cross-examination affords ‘to gauge the personality, motivations and working practices of a witness, rather than in testimony of what the witness recalls of particular conversations or events’. In my view, the pursuer provided a convincing account of his working practices and of the kinds of activities in which he was repetitively engaged. Indeed, one reason why he may have been able clearly to recall them was precisely because of their highly repetitive nature.”

He continued: “I have taken account of what Mr McKenzie described as the improbability, in the early 2000s, of a local authority, employing a clerk of works and a tendering process, exposing council tenants to the risk of asbestos exposure. But [the pursuer’s expert witness] Ms Conroy explained with the benefit of her considerable experience in this area, that she had seen asbestos being removed despite these measures having been in place. Mr McKenzie did not expressly invoke the presumption of regularity, but if that is what his submission came to, then I consider any such presumption had been rebutted by the evidence of the pursuer and his colleagues.”

Considering how to apportion liability, Lord Harrower said: “In my opinion, a nil apportionment would not be appropriate in a case such as this where ex hypothesi both defenders had been found to have caused or contributed to the loss. Ultimately, therefore, while in the circumstances of this case, I have found that the second defender must bear significant responsibility for the pursuer’s loss, Mr McKenzie offered no realistic submissions as to how that apportionment might be carried out.”

He added: “I was initially attracted by the default rule in section 3(4) of the Compensation Act 2006, providing that the defenders’ contributions should be determined according to the relative lengths of the periods of exposure for which each was responsible. However, I have come to the conclusion that this would be inappropriate in the present case primarily for two reasons. Firstly, the default rule effectively assumes an equal level of concentration of exposure with each defender across quite different tasks, which would be contrary to the evidence. Secondly, the default rule does not allow the court to avoid having to wield a broad axe, since even determining the relative lengths of the periods of exposure with each defender involves making very rough estimates. Against that background, I have adjusted the second defender’s calculation of the relative cumulative lifetime exposure to asbestos for each defender.”

Having performed those calculations, Lord Harrower therefore apportioned liability at 0.092 per cent to the first defender and 99.908 per cent to the second defender.