General protection for purchasers of food
4.—(1) A person who sells to the prejudice of the purchaser any food which is not—
(a)of the nature, or
(b)of the substance, or
(c)of the quality,
of the food demanded by the purchaser, shall, subject to Article 5, be guilty of an offence.
(2) In paragraph (1) the reference to sale shall be construed as a reference to sale for human consumption; and in any prosecution under that paragraph it shall not be a defence to allege that the purchaser was not prejudiced because he bought for analysis or examination.