Dear Grade,
Shelf life of Stock 939 is 2 years and we can extend shelf life by another 50% (which is 1 year for this product) depending on test results.
If PSP is keen to do shelf life extension, please draw sample from actual drum and send to LSAL for testing.
Do note that shelf life extension is from re-test date. I would suggest that PSP send us the sample closer to the expiry date in order to max out the shelf life.
250ml sample would be sufficient.