What you need to know about benzene following the mass recall of hair products

What you need to know about benzene Chemist John Sorensen discusses what benzene is, how it ends up in certain products and why it is dangerous.

Last week Health Canada issued a mass recall of more than one million hair products containing the cancer-causing chemical benzene.

The affected products included dry shampoos sold over the last two years by the Unilever brands Bed Head TIGI, Dove and Tresemmé.

Along with this recall, a new study also found that Benzene may be leaking off of gas stoves.

To explain what the chemical is and why many people are only learning about its dangers now, CTV Morning Live Winnipeg spoke to University of Manitoba chemist John Sorensen, who explained that benzene is a member of a class of molecules called aromatic hydrocarbons.

He added that it is a natural product that is produced in nature from the decomposition of organic matter.

“But also our primary source of it is from hydrocarbons, so fossil fuels or anything that we produce through that. Benzene is a major constituent of that,” he said in an interview on Wednesday.

“So that’s our main exposure to benzene is through the use of fossil fuels.”

As for what is harmful, Sorensen said benzene causes cancer by interfering with the process of DNA replication.

“It can insert into the DNA and prevent it from being copied correctly,” he said.

“More significantly for us, when we’re exposed to the benzene molecule itself, it’s transformed in our body to something that can irreversibly bind with the DNA and that really causes the problems of DNA replication and leads to the cancer we observe in exposure.”

Sorensen said the reason that benzene is ending up in hair products is because the propellants in the products are actually hydrocarbons.

“The benzene is probably coming from just a little bit of the trace of the benzene left in the process – the distillation process that we use to get those hydrocarbons,” Sorensen said.

He added the amount of benzene in these products is quite small, but known exposure to benzene is a problem so it’s best to eliminate exposure as much as possible.

“In day-to-day, our exposure to benzene is fairly small, so we do like to do things that eliminate that risk, because it is a known cancer-causing agent,” he said

As for benzene and natural gas stoves, Sorensen said it’s coming from incomplete combustion.

“If the flame isn’t hot enough or there’s another problem with the burner, it’s probably producing a little bit of benzene as a result of that,” he said.

He said the amount of benzene with gas stoves is also quite small, so the risk is low as long as you have good ventilation in your kitchen.

Sorensen added that the highest risk of exposure to benzene is actually from the day-to-day world in the urban environment.

“If you’re pumping gas then you’re exposed to benzene because it’s part of the hydrocarbons that go into your gas tank,” he said.

“The exhaust from your car also contains a measurable amount of benzene and is also part of the risk.”

He added that it is hard to avoid exposure because it’s part of the environment, but day-to-day levels of benzene exposure are still below the levels that are believed to cause any immediate risk.

- With files from CTV’s Nicole Dube and Megan DeLaire.