Ottawa has designated eight chemicals as being of concern to human health or the environment following its latest assessment of potentially dangerous substances.

The designated chemicals include silicon-based D4 and D5, which are used in a wide range of cosmetic products.

The joint assessment by Health Canada and Environment Canada means the chemicals can now be regulated. The latest assessment is part of a process of reviewing 200 chemicals in batches of up to 30 to determine whether they pose a risk to human health or the environment and should be more closely regulated.

It's the same process under which the federal government announced it would ban the import and sale of baby bottles made with bisphenol A.

Interested parties now have 60 days to comment on any risk management that may be required in the case of the eight newly named chemicals.

Of the eight chemicals placed on Ottawa's list, D4 and D5, along with TTBP, a fuel and oil additive, are not considered a threat to human health but are listed as of concern to the environment, including wildlife.

The ministers of health and environment issued a joint news release Tuesday stating "regulations will be developed to set a concentration limit for siloxanes D4 and D5 in products and for wastewater generated during the manufacturing process.

"The third substance [TTBP] will be managed so that releases to the environment will be reduced below levels that can be measured."

Harm to environment, carcinogenic effects among dangers

D5 is used in pharmaceuticals, cosmetics and cleaners as well as inks, textiles, rubbers and fuel additives. It is considered bioaccumulative and can harm aquatic organisms at low concentrations.

D4 is another silicone fluid used in types of rubbers, plastics, soap, pharmaceuticals, and cosmetics — including creams, lotions, hair care products and antiperspirants — as well as pesticides, paints, lacquers, varnishes, inks, textiles, leather goods and fuel additives.

Ottawa has said experimental data shows that D4 is persistent in the environment and can harm aquatic organisms at low concentrations.

Tuesday's release also lists five other chemicals as of concern to human health. They are thiourea, Pigment Yellow 34, Pigment Red 104, isoprene and epichlorohydrin.

Thiourea is used to extract silver and gold from ore and occurs naturally in some plants and fungi. Europe and the U.S. have classified it as a compound that should be examined as a possible carcinogen.

Pigment Yellow 34 and Pigment Red 104 contain chromium and lead and are used to colour plastics, inks, paints, coatings, adhesives, textiles and sealants. In addition, the European Commission classified Pigment Yellow 34 based on concerns that it may be carcinogenic and toxic to the reproductive system.

Isoprene is used to make medical equipment, toys, tires and paints, inner tubes, and some rubber adhesives and glues. The federal government decided to take a closer look at this chemical after other jurisdictions classified it as a possible human carcinogen.

Epichlorohydrin is a synthetic chemical used to make other chemicals and is classified as a possible human carcinogen by the European Commission and the United States Environmental Protection Agency.