proposed prohibition of certain toxic substances regulations 2012 40 pages available in english and french the proposed regulations are a multi-substance risk management instrument used to prohibit the manufacture use sale offer for sale or import of certain toxic substances as well as products containing these substances. when the prohibition of certain toxic substances regulations first came into effect in 1996 they covered 5 substances. these regulations have subsequently been amended and now contain controls for 18 substances. these proposed regulations introduce the following changes with respect to the current regulations new substances subject to controls four new substances are being proposed to be added 1 benzenamine n-phenyl- reaction products with styrene and 2 4 4-trimethylpentene bnst 2 polychlorinated naphthalenes pcns 3 short-chain chlorinated alkanes and 4 tributyltins tbts the final risk assessment reports on bnst short-chain chlorinated alkanes pcns and tbts concluded that these substances may be harmful to the environment and are toxic as set out in the canadian environmental protection act 1999 cepa 1999 . the final risk assessment reports also concluded that short-chain chlorinated alkanes may pose a danger to human health. in addition all of these substances were found to meet the criteria for persistence and bioaccumulation as set out in the persistence and bioaccumulation regulations. as such it was recommended that these substances be added to the list of toxic substances in schedule 1 of the cepa 1999. in december 2009 parties to the united nations convention on long-range transboundary air pollution amended the protocol on persistent organic pollutants to add seven new substances the amendment including pcns and short-chain chlorinated alkanes. once parties ratify the amendment adding pcns and short-chain chlorinated alkanes to the pops protocol they will be required to eliminate all production and use of these substances. adding pcns and short-chain chlorinated alkanes to the proposed regulations is expected to put in place the required domestic measures that would allow canada to consider ratifying the amendment adding these two substances. updating existing restrictions on the use of hexachlorobenzene hcb the proposed regulations would modify controls on the substance hcb so as to broaden the prohibition and ensure continued compliance with international obligations. administrative changes the proposed regulations would further include administrative changes consisting of specific wording revisions and harmonizing the english and french language versions of the current regulations. they also include simplifying reporting requirements for industry