In order to minimise the number of changes in batch number, the “Current Lot” system is used. When a substance is released for use as a BPCRS this substance is retested regularly to confirm its continued suitability for use. No expiry date is given and the substance is replaced only when exhausted (or in rare cases when it is no longer suitable for use). This system reduces the number batches replaced due to expiry and helps to reduce the costs of producing BPCRS. All BPCRS are supplied with a shelf life of 3 months from the date of despatch to allow customers to use BPCRS after they have been replaced by a new batch. The current batch number (Batch No.) is always listed on the website.