Fire Blanket maintenance is usually annual & your extinguisher servicing company should automatically do this, ideally at a lower unit cost (wishful thinking), & affix a service label.
what do you look for?:
- Fraying, tears, delamination, bobbling, disintgration, stifening of fabric showing effects of environment & age which wouldrisk blanket failure of fail to drape
- missing or damaged pull/grab tapes
- fabric being coated or soaked in grease or other contaminant (common in kitchens where the container is open or has the lid missing)
- evidence of use on a fire
Any of these will fail a blanket and require a new one. Also look for
- location (easy to get too, not above the risk)
- still adequate for risk (have fryers over 300mm or 15 litres been introduced - provide wet chemical as well; is it a 3' x 3' blanket when the risk includes welding and the need to cover a person)
BS6575 is obsolete, as is the even older fabric test to BS475 on older blankets, BS 1869 is the current spec, however older standard blankets whilst they pass inspection may still be used, although beware on intense Class B or F fires they (particularly the old BS475 ones) have a lesser performance.
It is rare, but not impossible to still find asbestos blankets (I always seem too!!). Under no circumstances remove from container, but bag and seal container, add hazard markings and arrange specialist disposal