Anna A. Stec of the University of Central Lancashire reported the findings at an annual meeting of the American Chemical Society in San Diego Tuesday.
Stec said her study focused on the most widely used category of flame retardants containing the element bromine
Such retardants are termed "halogen-based" because bromine is in a group of elements called halogens.
"Halogen-based flame retardants are effective in reducing the ignitability of materials," Stec said. "We found, however, that flame retardants have the undesirable effect of increasing the amounts of carbon monoxide and hydrogen cyanide released during combustion.
"These gases, not the thermal effects of burns on the body, are the No. 1 cause of fire deaths."
To determine the effects of flame retardant composition on the production of those gases, Stec and her colleagues compared brominated flame retardants against mineral-based flame retardants and so-called intumescent agents, which swell when heated forming a barrier flames cannot penetrate.
The researchers found mineral-based fire retardants have little effect on fire toxicity, while most intumescent fire retardants reduce the amount of potentially toxic gases released in a fire.