Consumer Chemicals and Containers Regulations, 2001

Marginal note:Determination of the pH

• 44 (1) The responsible person for a corrosive product must determine the pH of the product by using good scientific practices that are in accordance with a procedure similar to that described in ASTM D 1293, from

  • (a) in the case of a product in the form of a liquid, the product as it is dispensed from its container; and

  • (b) in the case of a product in the form of a solid, paste or gel, or in a form otherwise unsuitable for direct measurement of the pH, a 10% aqueous solution of the product.

• Marginal note:Determination of acid reserve or alkali reserve

  (2) The responsible person for a corrosive product must determine, where applicable, the acid reserve or the alkali reserve of the product by

  • (a) titrating, in accordance with the OECD Principles of Good Laboratory Practice,

    • (i) in the case of a product in the form of a liquid, a suitable aliquot of the product as it is dispensed from its container, and

    • (ii) in the case of a product in the form of a solid, paste or gel, or in a form otherwise unsuitable for direct measurement of the pH, a suitable aliquot of a 10% aqueous solution of the product; and

  • (b) calculating

    • (i) in the case of an acidic product, the amount of an alkali, expressed in grams of sodium hydroxide, that is required to bring 100 mL of the product in the form of a liquid, or 100 g of the product in the form of a solid, paste or gel, to a pH of 4.00 ± 0.05, and

    • (ii) in the case of a basic product, the amount of an alkali, expressed in grams of sodium hydroxide, that is neutralized when 100 mL of the product in the form of a liquid, or 100 g of the product in the form of a solid, paste or gel, is brought to a pH of 10.00 ± 0.05 by the addition of hydrochloric acid.

• Marginal note:Unstable end point

  (3) If the end point of the titration referred to in subsection (2) is unstable and exhibits drifting, the pH end point reached within 30 seconds after the last addition of titrant is to be used as the effective end point for classification purposes.