§ 178
The Minister may cancel an exemption if
(a) the Minister is of the opinion that to not cancel the exemption may result in a risk of injury to human health;
(b) in the case of an exemption referred to in subsection 175(2), the Minister is of the opinion that to not cancel the exemption may result in a risk of harm to interprovincial trade or export; or
(c) the person who has been granted the exemption does not comply with any condition to which the exemption is subject or any provision of the Act or these Regulations other than a provision in respect of which the exemption is granted.