Laboratory Tests

Initial validation, sample labelling and request forms

Initial validation

For the initial plant validation under the scheme, the plant must demonstrate that they operate within the parameters specified in Tables 1 to 5 in the PAS 110. The initial validation requires 3 consecutive passes from 3 different portions of production. For example, if the hydraulic retention time is 40 days, samples of digestate should be taken at least 40 days apart. You should consider the timing of sample testing to coincide with spreading opportunities and laboratory capacity. 

Be mindful that the laboratories cannot test samples over the Christmas period and the final date for submitting samples is early December. 

Following validation, the plant must continue to submit samples in accordance with Table 4 of the PAS 110. For information on submitting samples, please contact the appointed laboratories directly using the contact details provided here.


We recommend you read through the BCS sampling guidance available here (for separated fibre, please use the compost sampling guidance here). Each final sample must be representative of the batch or portion of production sampled.

Labelling your PAS110 digestate sample

It is crucial that each digestate sample is labelled with the correct information before being sent to the laboratories for testing. This will provide a clear distinction between samples sent for trials or process improvement and samples sent for PAS110 validation or renewal testing, as we are only collating the latter. It is important that the laboratories understand whether your sample has been sent for certification purposes so that they know to submit the results to the BCS database.

If the testing is being undertaken for certification purposes, then please label your compost sample packaging with ‘PAS110’. If the testing is not being undertaken for certification purposes, then please do not label your sample with ‘PAS100’.

For instructions on how to label your sample and prepare the relevant paperwork, you can download the guidance here.

PAS 110 Digestate Analysis Request Form

Digestate samples sent to the laboratories for certification purposes will need to be accompanied by the PAS 110 Digestate Analysis Request Form, which can be downloaded here. The Microsoft Word version of this form can also be downloaded here.

PAS 110 test results

The PAS110 test reports associated with your certification will be uploaded directly to the BCS database by the laboratories. In order to do this, they require the correct certification code (whether existing or temporary). The laboratories will also send a copy of the reports to operators but please note that the certification bodies will only accept those results submitted to the BCS database. The laboratory test results will not become publicly available, although REAL may share anonymised sets of data externally for other purposes.