proposed order adding toxic substances to schedule 1 to the canadian environmental protection act 1999 9 pages available in english and french canadians depend on chemical substances that are used in hundreds of goods such as medicines computers fabrics and fuels. unfortunately some chemical substances can negatively affect human health or the environment when released above a certain quantity or concentration in the environment. scientific screening assessments of the following substances have concluded that these substances are entering or may enter the environment in a quantity or concentration or under conditions that have or may have an immediate or long-term harmful effect on the environment or its biological diversity as defined under paragraph 64 a of the canadian environmental protection act 1999 cepa 1999 also referred to hereafter as the act perfluorooctanoic acid which has the molecular formula c7f15co2h pfoa and its salts compounds that consist of a perfluorinated alkyl grou that has the molecular formula cnf2n 1 in which n 7 or 8 and that is directly bonded to any chemical moiety other than a fluorine chlorine or bromine atom precursors of pfoa perfluorocarboxylic acids that have the molecular formula cnf2n 1co2h in which 8 8804 n 8804 20 long-chain pfca and their salts and compounds that consist of a perfluorinated alkyl grou that has the molecular formula cnf2n 1 in which 8 8804 n 8804 20 and that is directly bonded to any chemical moiety other than a fluorine chlorine or bromine atom long-chain pfca precursors . the objective of the proposed order adding toxic substances to schedule 1 to the canadian environmental protection act 1999 hereinafter referred to as the proposed order made under subsection 90 1 of cepa 1999 is to add pfoa its salts and precursors and long-chain pfcas their salts and precursors to the list of toxic substances in schedule 1 of cepa 1999. this addition enables the minister of the environment and the minister of health the ministers to propose regulations or other risk management instruments to manage environmental risks posed by these substances under cepa 1999. the ministers may however choose to develo instruments outside of the purview of cepa 1999 in order to manage these risks.