Health Canada is advising Canadians to avoid using borax to make kids’ arts and crafts, such as homemade “slime,” over concerns that too much exposure to all forms of boric acid can cause “developmental and reproductive health effects” in children and pregnant women.

Borax is a salt of boric acid and often sold in powder form as a “laundry booster.”

Because it is highly alkaline and can dissolve oils and fats, borax is also an effective household cleaner, and seen by some -- including the David Suzuki Foundation --as more eco-friendly than petroleum-based cleaning products. Most of these products warn that borax can be an eye and skin irritant and should never be ingested.

But in an update posted to Health Canada’s website this week, the agency says it is concerned about Canadians’ exposure to all forms of boric acid.

A recent draft risk assessment completed by Health Canada scientists found that too much exposure to boric acid has the potential to cause developmental and reproductive health effects.

“Since Canadians are already exposed to boric acid naturally through their diets and water, Health Canada is advising that exposure from other sources should be reduced as much as possible, especially for children and pregnant women,” the agency said in the update.

“The concern is not with any one product, but rather multiple exposures from a variety of sources.”

As such, Canadians are being advised to minimize their exposure to boric acid by not using borax in children’s arts and crafts at home, such as mixing it with white glue to create "slime" or "silly putty."

They are also advised not to use the mineral to make homemade pesticides.

Health Canada advises homeowners to follow all directions on cleaning products and store them out of sight and out of the reach of children.