HL Deb 09 March 1998 vol 587 cc17-8WA
The Marquess of Ailesbury

asked Her Majesty's Government:

What is their estimate of the reading which a breathalyser would give at (a) 7 am and (b) midday if the person concerned had given a reading of 80 mg/ml at midnight and consumed no alcohol after midnight. [HL884]

Baroness Hayman

Any person whose blood alcohol level at midnight was reliably recorded as 80mg/100ml—the current legal limit—by means of a breath test, and who consumed no further alcohol would be unlikely to retain more than, at most, 10mg/100ml by 7 am and a negligible quantity by midday.