For years firefighters and environmentalists have warned of the dangers from upholstered furniture treated with flame-retardant chemicals that are linked to cancer, decreased fertility, hormone disruption and lower IQ development. Although state safety regulations allow the use of flame retardants, they are not required — the choice is left to manufacturers. Today Californians wishing to buy a sofa or easy chair free of toxic chemicals are in for a surprise when they try to get information in stores about the presence or absence of flame retardants. An informal survey of West Los Angeles furniture showrooms recently encountered these scenes: