Acid safeguards

SIR – I agree with Adrian Waller (Letters, July 17) that it is illogical that one cannot buy nitrogen fertiliser without a licence, but sulphuric acid is on sale to anyone.

Over the years I have bought several bottles of this acid to clear our drains, and am always surprised that the seller has never asked for proof of identity. Keeping a record of purchasers of this dangerous substance is clearly not currently required, but perhaps it should be.

This simple measure might act as a deterrent to would-be attackers, even if investigating such logs would be too labour-intensive for police with their current resources.

Dr M C Moore

Borehamwood, Hertfordshire