Mixing it up: Examining new substances in Canada

We are exposed to numerous chemical substances as we go about daily routines. How do we know they are safe? Well, Deborah Ratzlaff and her colleagues in Health Canada’s New Substances Assessment and Control Bureau make sure they are! Her team of biologists and chemists is hard at work helping to ensure that the newest substances appearing on the market in Canada are safe for you and the environment.

Working closely with colleagues from Environment and Climate Change Canada, Deborah and her colleagues examine the potential risks substances have to Canadians and the environment before they enter the Canadian marketplace. In fact, since the 1990’s, the program has assessed more than 20,000 files.

What’s a substance?

A substance is something that is deliberately created or that occurs naturally in the environment. Substances can be chemicals, polymers or living organisms. They can be found everywhere, and they form the main building blocks of the products that we use every day.

Substances used in Canada are found on the Domestic Substances List (DSL). Any substance that isn’t on the DSL is considered new to Canada and must be evaluated. Since its creation, the New Substances Program has evaluated and added more than 5,000 substances to the DSL.

Examining new substances

Anyone who wants to produce or import a new substance, to use it in industrial coatings or cosmetics or a broad range of other contexts, must notify Health Canada and provide scientific studies that demonstrate the safety of the new substance.

Deborah’s team also works with researchers in other parts of Health Canada, and other departments such as Environment and Climate Change Canada and Agriculture and Agri-Food Canada. Results of their research provide additional data that is used to validate predictions and refine evaluations to help ensure the right decisions are made.

Typically, Health Canada evaluates how the substance could impact human health. For substances used in cosmetics, pharmaceuticals, natural health products, biologic drugs, medical devices and food additives, Health Canada also evaluates the impacts on the environment. That’s where Deborah’s team comes in!

The team looks at the expected use of a substance and predicts how much could end up in the environment, how long it will stay there and whether it accumulates in the food chain. They also determine whether the new substance could harm wildlife or water sources, and ultimately affect human health.

“When a company wants to include a new chemical in your shampoo, for example, we consider that you will be using it on your body and that it will then be rinsed down the drain,” explains Deborah. “We follow that chemical through the entire cycle of use, disposal and release into the environment to find out where it ultimately ends up and if it could cause any damage along the way.”

If the evaluation determines the substance could be harmful to human health or toxic to fish or other living organisms, restrictions can be imposed or more data can be requested.

Deborah is particularly interested in how substances we use everyday can affect the environment. “The environment doesn’t get to choose which substances we use. We have to consider the impact when we use them,” she says.

This important work is done by a dedicated group of people who really care about making a difference. Thanks to them, we can rest assured that new substances coming into Canada have been screened for their impacts on the environment and human health.


Let’s draw attention to the incredible work of women in science! This article is part of a month-long series celebrating women in science, from International Day of Women and Girls in Science (February 11) to International Women’s Day (March 8).