Why does cement have a packing date and maximum storage period specified (or “expiry date” or “shelf life”) and can I use it after this date?

Cement contains chromium and this can cause allergic contact dermatitis due to sensitisation of the skin. Manufacturers add an ingredient which reduces the amount of soluble chromium in the cement and this reduces the risk of allergic contact dermatitis. The added ingredient is only effective for a limited period, after which the level of soluble chromium may increase again. After the date stated, the cement should not be used unless each pack is first tested to determine that the level of ‘chromium VI’ is 2 parts per million or below.

Cement used in processes that are controlled, closed and totally automated, such as on a closed production line in which cement and cement-containing preparations are handled solely by machines and in which there is no possibility of contact with the skin, are exempt from these requirements.