These Regulations amend the Weights and Measures Act 1985 and the Units of Measurement Regulations 1986, both of which make provision for legal units of measurement for use in the United Kingdom. These Regulations partly implement Commission Directive 2019/1258 amending, for the purpose of its adaptation to technical progress, the Annex to Council Directive 80/181/EEC as regards the definitions of SI base units (OJ L 196, 24.7.2019, p. 6), which relates to the definition of units of measurement. The amendments in the Commission Directive update European law to reflect seven new definitions of expressions of measurement and indications of quantity of the International System of Units (SI) adopted by the General Conference on Weights and Measures at its 26th meeting which took place from 13th to 16th November 2018 (see The International System of Units (9th edition 2019) edited by the International Bureau of Weights and Measures, Pavillon de Breteuil, F-92312 Sèvres Cedex France, ISBN 978-92-822-2272-0). The amendments do not alter the value of those units of measurement, but substitute new definitions expressed in terms of natural constants.

Regulation 2 amends the definition of the ampere in Part 7 of Schedule 1 to the Weights and Measures Act 1985, and amends the definition, in the same Part, of the watt in relation to the reference to the second, to ensure consistency of interpretation.

Regulation 3 amends the Units of Measurement Regulations 1986 by substituting a new paragraph 1 in Schedule 1 to those Regulations to reflect the substitution made by the Commission Directive of section 1.1, Chapter 1 of the Annex to Council Directive 80/181/EEC. New definitions are provided for the second, metre, kilogram, ampere, kelvin, mole and the candela. A small amendment is made in the representation of the decimal point in the definition for the degree Celsius.

An impact assessment has not been produced for this instrument as no, or no significant, impact on the private, voluntary or public sector is foreseen.