LOS ANGELES, March 14 (Xinhua) -- Dozens of popular "green" products in the United States contained a cancer-causing chemical that is a byproduct of petrochemicals used in manufacturing, the Organic Consumers Association (OCA), a consumer advocacy group announced on Friday.

    The cancer-causing chemical is found in almost half of 100 such goods studied. Of the 100 products tested, 47 had detectable levels of 1,4-dioxane, which the Environmental Protection Agency has declared a probable human carcinogen because it causes cancer in lab animals, the OCA said.

    The OCA announced the findings at a national trade show in Anaheim, Los Angeles.

    Many items that tested positive for the carcinogen are well-known brands, including Kiss My Face, Alba, Seventh Generation and Nature's Gate products, sold in retail stores across the nation, according to the OCA.

    "For companies to knowingly or even carelessly put a carcinogen into commerce in this day and age is barbaric, I think, particularly products that have the moniker of natural or self-proclaimed 'organic,'" said consumer advocate and author David Steinman, who directed the study.

    "We need standards," he said. "Consumers walk into a health-food store or natural-product supermarket with the expectation that the product they purchase will be natural or safer than what they could purchase at the drugstore or supermarket."

    The findings are sending a jolt through the natural products industry and will taint the industry in the eyes of the public, said participants attending the trade show.

    Most traditional soaps and shampoos contain 1,4-dioxane. But the discovery that the chemical is present in many housecleaning and personal care products, including some for babies, that are advertised as being natural, organic or "green" comes as somewhat of a surprise.

    The chemical, a byproduct of a process used to soften harsh detergents, is formed when foaming agents, or surfactants, are processed with ethylene oxide or similar petrochemicals.

    Experts said it is deceptive for many products to be called natural when the carcinogenic compound indicates that petrochemicals are used in their manufacture.

    So far there are no standards that govern the words natural or organic for personal care products.