Critics are raising concerns about pills marketed by an exhibitor at a consumer trade show in Ottawa this past weekend as safe, legal alternatives to drugs such as ecstasy.

Two products containing 3-Trifluoromethylphenylpiperazine (or simply TFMPP) and Benzylpiperazine (BZP) were touted by the Toronto-based wholesaler and distributor Pure Pillz at Sexapalooza, which took place at Lansdowne Park Jan. 18-20.

Régis Vaillancourt, a pharmacist at the Children's Hospital of Eastern Ontario, said use of the ingredients have been linked to seizure disorders, acute renal failure and in two cases, death.

"So if you're asking me if it's dangerous, I would say yes," he told CBC News Monday.

On its website, Pure Pillz describes the products as club or party pills "designed to be a safe and legal alternative to illegal drugs, giving you a range of social experiences from e-sensory fun to strong energy boosts."

BZP has been banned in recent years in the U.S., Australia and Denmark, but the ingredients are not regulated in Canada.

Vaillancourt said the chemical structure of BZP is similar to that of a drug that was used to treat intestinal worms.

"The way they work is by making the worms dizzy, if you want, or drowsy," he said, adding that helps expel the worms.

"What they do is they play chemically with that product, and it has physically hallucinogenic properties like ecstasy."

After hearing concerns about the pills, Sexapalooza show manager Liz Lewis said she planned to do more research on the product.

"My staff and I have purchased a few of them and we were going to try them and see just what they're like," said Lewis, who is preparing for another show in Hamilton Feb. 29 to Mar. 2.

She added that it was the show's first year and the concerns about the Pure Pillz products were the only ones she had heard regarding any of the exhibitors.