Weights and measures
I have a large bottle of Joigel hair gel in the bathroom. I just noticed this morning that it is a 1 kg container. By contrast, the bottle of shampoo in our shower is a 400 mL package. The two substances (gel and shampoo) are roughly the same consistency, and they're both for hair. One is measured by weight, the other by volume. Why is that?
Canadian government regulations specify that:
the declaration of net quantity of a prepackaged product shall show the quantity of the product
(a) by volume, when the product is a liquid or gas or is viscous, or
(b) by weight, when the product is solid,
unless it is the established trade practice to show the net quantity of the product in some other manner, in which case the declaration shall be in accordance with the established trade practice. SOR/78-171, s. 1.
Both products seem "viscous" to me, and so should be measured by volume. But perhaps "established trade practice" in the hair products industry puts the line between solid and liquid directly between the solidy liquidness of shampoo and the liquidy solidness of gel.