CL-2022-000676 - [2025] EWHC 2486 (Comm)

There was then a distinction between the parties as to whether the Contract required a formally validated process (ie via compliance with BS EN 556-1:2001 and CE marking or similar); this was the DHSC’s primary case. Another possibility, tacitly advocated by Medpro’s case on contractual construction (and effectively accepted in practical if not contractual terms by DHSC) is that it would potentially be possible to establish compliance by providing documents which established either that the gowns had undergone a process covering all relevant stages, or that they had separate certifications to cover all the constituent parts of the sterility assurance process (ie some form of ongoing audit of the sterilisation process).

As regards this point only (and ignoring the other construction arguments) this seems a perfectly reasonable approach. In other words, one method of establishing SAL compliance, if that were the only question, would be for the person in the position of Medpro to produce a sheaf of individual certificates documenting each stage of the process. This is similar to but not identical with the provision of an ISO 11137 Part 1 certificate (which did occur here). It is not identical because each part of the process must be documented. It is not enough to certify one part if the others are not also vouched for. Achievement of the requisite SAL can be derailed by not properly establishing a sterilisation dose, or by (while knowing the right dose) not validating it to ensure consistency or by not applying it properly either at all or over time.

This approach also partially merges into compliance with EN 556-1; because that is done via a CE marking with a notified body number, but the ability to add a notified body number equates to saying that A+B+C+D have been established by the means set out in the standard. Thus I conclude that an appropriate SAL could equally be proved by producing the individual evidence for A, B, C and D.

However that does not answer the question of whether there was compliance with validation requirements as to SAL in this case. The answer to this question is a clear no. This result can be arrived at by a short route or a longer one.

The starting point is via the experts’ joint statement.The sterility experts’ Joint Report agrees, at paragraph 2.1, that “information normally required to demonstrate a fully-documented performance qualification as expected by EN ISO 11137-2 (and EN ISO 11137-1) was not provided”. In a sense that answers the question; but since it theoretically leaves open the possibility that there is nonetheless evidence, though not that “normally required” which can demonstrate a fully-documented performance qualification, it is necessary to interrogate the stages involved.

The short route from here is to ask whether there is evidence of dose setting by an appropriate method (the defined methods in BS EN ISO 11137-2:2015 or any other method). It is common ground that there is no such evidence.

The longer route is to consider what there is. There is what was referred to as “the Dasheng Report” (there were no reports for other irradiators). That document has sections dealing with responsibility, procedure, preparation, dose mapping, dose measurement and batch processing, but not dose setting. Importantly, it notes as follows:

“The customer shall provide the sterilization dose specification and 3 units of product.

The QC Department .. shall determine the loading pattern of products, in order to get a fine uniformity of dose distribution in products and obtain the maximum efficiency of radiation processing. According to the DOSE SETTING from customer, formed the PQ protocol, including the dosimeter position, the quantities and process parameters.”

In other words, Dasheng does not purport to do all the stages of ISO 11137-2. Critically it does not purport to do the complicated dose setting process outlined above, but relies on the customer to stipulate a dose. Dasheng would take the dose and test only to ensure “a fine uniformity of dose distribution”.

There are also irradiation certificates. These are a record of the doses of irradiation that have been applied to the gowns; some express the doses as the minimum and maximum applied as compared with the specification, some express the applied dose as an average dose, and some state only the minimum absorbed dose (not the maximum). These also suggest the dose was set by the customer (WTT).

Mr Atchia in his first report annex stated it is “unknown how these maximum and limits were established”. While Mr Atchia and Medpro’s legal team urged an inference that obviously the irradiators would have done dose setting first, and no reputable company would do otherwise (see Mr Atchia’s evidence that no company that he had ever audited, inspected or assisted would have conducted the Dasheng dose calibration experiment without first conducting sterilising verification dose exercises) (i) inference is not validation and (ii) that inference is, on the facts of this case, plainly unsafe when taken against the actual evidence from the reports from Dasheng which indicated clearly that “The customer shall provide the sterilization dose specification” and the fact that the irradiation certificates appear to show doses having been set by the customer.

The result is that what there is leaves a glaring gap: as Dr Richards said there is no “microbiological qualification of the irradiation dose and all we refer to is a statement that the textile company is providing an assurance that an [sic] SAL to the minus 6 is achieved with no supporting data…”

That segues into the next aspect of the failure: bioburden and its impact on the right dose. It is fairly obvious (and clear from ISO 11137: 2 Table 5) that the amount of irradiation needed will depend on how dirty the items are – or in technical terms how much of a bioburden there was. Mr Atchia accepted in his reports that there must be a process which can be validated to demonstrate and document SAL, which will include analysing the bioburden.

However, there is no documentation to show that the bioburden of the gowns was assessed as part of a dose-setting exercise. As Dr Richards said there is no “microbiological qualification of the irradiation dose…”

There are some records of microbial cleanliness, but they were produced for the purposes of other inspections, not as part of any dose-setting exercise. Mr Atchia accepted that was the case. It was noticeable that (i) Medpro steered entirely clear of the concept of bioburden except as regards the ex post facto testing and what could be inferred from it and (ii) Mr Atchia was driven to attempt to work backwards to a conclusion. He performed an exercise of inferring what that bioburden was by working backwards from an assumption that the sterilising dose is correct and using the information contained in Table 5 of EN ISO 11137-2:2015. He then sought to support the calculation by relying on the limited cleanliness and bioburden data available from tests conducted on the gowns by Intertek and GTTC as part of their manufacture. However, as became clear in cross examination, this approach was not helpful to Medpro. It became apparent that Mr Atchia had misunderstood the figures given in the Intertek and GTTC reports – and that as a result the figure he was using was understated by a factor of 100.

The more accurate analysis (albeit one with which the experts were not entirely happy) proceeds thus:

On that basis prima facie irradiation would not have achieved the requisite SAL at the level of irradiation which the manufacturers stipulated for with the irradiators (where there is evidence, it was from 18.2 kGy to 20.3 kGy).

Accordingly on the true construction of the Contract there was a requirement for a validated process; and in breach of the Contract there was no validated process. The evidence which there was did not establish two key parts of the process had been undertaken: bioburden testing and dose setting.

Subject to questions of estoppel, therefore, liability can be established at this stage.