The Safety Letterbox Company works with the Fire Research Laboratory in developing a range of 1-hour fire-rated mailboxes.

The mailboxes are particularly suitable for use when mailboxes have to be positioned on a designated fire escape route or banked in a post room that must be fire rated.

They satisfy the integrity criteria given in BS 476-22:1987 Clause 8 for a period of 60 minutes.

The mailboxes can be further enhanced by applying a finish that conforms to BS 476-6 and -7 London Underground surface spread of flame requirements.