This test method covers laboratory determination of the efficiency of liquid membrane-forming compounds for curing concrete@ as measured by their ability to reduce moisture loss during the early hardening period. The values stated in SI units are to be regarded as the standard. The values given in parentheses are provided for information purposes only. This standard may involve hazardous materials@ operations@ and equipment. This standard does not purport to address all of the safety concerns associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Warning??Fresh hydraulic cementitious mixtures are caustic and may cause chemical burns to skin and tissue upon prolonged exposure.