This was taken from the lea&perrins website under FAQ:

Q. Can I use Lea & Perrins� products / sauces after the expiration date?
A. Lea & Perrins� sauces won t spoil after the expiration date due to the high vinegar content. However, the taste quality will lessen if used after the expiration date.

Q. Can I use Lea & Perrins� products / sauces out of the refrigerator?
A. Lea & Perrins� sauces can be used out of the refrigerator and has a standard shelf life of 24 months. But refrigeration helps to preserve the flavor and the shelf life even longer.

Q. Do you need to refrigerate the product?
A. Lea & Perrins� Worcestershire Sauce doesn t need to be refrigerated, but refrigeration does help to preserve the flavor and shelf life of the product.