Proof and de minimis in Asbestos cases

Valerie Bannister (Widow and Executrix of the Estate of Dennis Charles Bannister, Deceased) v Freemans PLC

[2020] EWHC 1256 (QB), before Geoffrey Tattersall QC sitting as a Deputy Judge of the High Court


This was a mesothelioma claim where, ultimately, the Claimant lost on the facts and so did not prove any exposure to asbestos by the Defendants.  However, the Judge found that the alleged exposure to asbestos, if it had been proved, would have been so small that it would have been considered to be de minimis.  It is a useful case for practitioners where exposure to asbestos has been very limited.


The claim was brought by the widow of the Deceased who had died of mesothelioma at the age of 73, about a year before the hearing.

The Deceased did not, in fact, regularly work with asbestos or come into contact with anyone who did.  The Deceased worked as a manager in the Defendant’s Accounts Department – the well-known mail order catalogue company – between 1977/8 and 1988/89.  However, it was alleged that on one occasion a partition wall had been removed over the course of a weekend, and that asbestos dust had been left on his floor and desk which was gradually removed by the cleaners over the course of the following week.

The claim was essentially a matter of whether the Claimant had been exposed to asbestos as claimed.  If so, what was the level of exposure and was this a “material increase in risk”


The Judge gave a helpful rendition of the law in relation to mesothelioma as it stands.  He noted the Fairchild and Sienkiewicz rulings setting out that a defendant will be liable if it had ‘been responsible for exposing the victim to a significant quantity of asbestos and thus creating a material increase in risk’.  Paragraphs 107 – 108 of Sienkiewiczwere set out, thus explaining that the court would by the insertion ‘of the word “material” is intended to exclude an increase of risk that is so insignificant that the court will properly disregard it on the de minimis principle.’ Sienkiewiczrejected the argument that this would need to be as high as a doubling of the risk and stated that it would be a matter of fact in any individual case.

The Judge found that section 3(2) of the Compensation Act 2006 would only cause a defendant to be jointly and severally liable in cases where there had been a negligence or a breach of duty, and that this would not be the case where exposure had not materially increased the risk.

The Judge noted the Deceased’s witness statements, his evidence given in cross-examination on commission, his application for Industrial Injuries Disablement Benefit and evidence from a colleague.  The Judge noted a number of inconsistencies and how some of the Deceased’s recollections appeared to be prompted by the witness statement of his colleague. 

The Judge then considered the matter of reliability of historical lay evidence.  The Judge considered the difficulties of oral evidence in the absence of documentary evidence in support, but noted that there would inevitably be difficulty in such cases owing to the long latency periods of the disease.

As to the engineering evidence, it was of course a matter for the court whether the removal of the partition did take place and what materials it contained.  It was noted that the presence of dust did not prove that it was asbestos dust rather than another material.

On the facts of this case the Judge found that the partition had probably contained asbestos, but that it had probably been removed by reputable and specialist contractors and so they would not have allowed asbestos dust to be present in the room following the removal.  However, the contractors who had replaced the partition with a non-asbestos material would probably not have been concerned by the presence of dust.  Accordingly, any dust which was left probably did not contain asbestos.  It followed that the finding of fact was that there had been no exposure to asbestos.

However, the Judge went on to consider the extent of exposure and any liability in the event that the Deceased had been, in fact, exposed to asbestos dust in the manner alleged.

The Judge then went on to consider the expert reports of the engineering experts as to the amount of exposure in the circumstances alleged, including the exposure during the week following the removal.

In the engineering joint statement the exposure was considered to be between 0.00014 – 0.00068 fibre/ ml years, though both engineers considered this to be illustrative rather than definitive.  Following cross-examination, it appeared that the engineers each came to the conclusion that exposure was probably in the region of 0.0004 fibre/ ml years.

As to causation, the Judge found that this was mixed fact and law.  He considered that he should follow the Sienkiewicz finding that what was a material increase in risk was a matter for the judge based on the facts of the case.

The Judge found, accordingly, that any exposure to asbestos would not be sufficient to fulfil causation.  The Judge expressed his caution about relying on epidemiological evidence, but accepted that it had a limited role to play in his Judgment.

The Judge carefully considered the medical expert’s evidence in their reports and under cross-examination.  Essentially the Defendants expert considered the risk at the exposure was ‘vanishingly small’ and the Claimant’s expert considered it to be ‘very small but more than negligible’.  The Defendant’s expert considered the increase in annual risk to be 1 in 50 million; the Claimant’s expert did not agree with the methodology for coming to such a risk, but did not have an alternative figure available.  The Claimant’s expert conceded that there would be some cases where exposure was so trivial that he would not consider them to be material, though did not agree that this was such a case.

The Judge found that the risk was approximately 1 in 50 million annually, noting in passing that the HSE considered an ‘acceptable risk’ to be 1 in 1 million.  

Accordingly, the Judge found that the Claimant had not shown that the alleged exposure was more than de minimissince it did not cause a material increase in risk of mesothelioma.


Of course, this case serves to remind practitioners that any exposure to asbestos is not enough to show a material increase in risk.  

It also shows the difficulty of historic evidence and the difficulties judges will have in accepting such evidence were there are inconsistencies.

Link to the case on Bailii