# Feeding Stuffs (Sampling and Analysis) Regulations (Northern Ireland) 1999, Paragraph 3.2: Reagents

Extent: N.I.
Status: prospective

Formaldehyde solution: the strength of the commercially available solution should be checked as follows: mix 3 ml formaldehyde solution with 50 ml 1N sodium hydroxide solution and 25 ml hydrogen peroxide solution (20 volumes). Heat on a steam bath until effervescence stops. Cool, and titrate with 1N hydrochloric acid using phenolphthalein indicator. Carry out a blank titration using 3 ml water in place of the formaldehyde.
1 ml of 1N sodium hydroxide ≡ 0.0300 g formaldehyde
strength of formaldehyde solution ≡
(B-T)×0.0300×100g3per100ml where:
B = blank titre; and
T = sample titre.

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Source: https://www.legislation.gov.uk/nisr/1999/296/schedule/2/paragraph/3.2 (the official version)
Page: https://openlegislation.uk/feeding-stuffs-sampling-and-analysis-regulations-northern-ireland-1999/schedule-2/paragraph-3.2
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.