ANAHEIM, Calif. — There might have been plenty of new products at the Natural Products Expo West, but all the buzz at the show was about something called 1,4-Dioxane.

In a report made public at the expo on March 14, numerous products from some of the best-known organic-natural personal care and household cleaning lines were shown to contain 1,4-Dioxane, a chemical known to be carcinogenic. The toxin is a by-product of ethoxylation, a process used by some companies to mollify certain harsh ingredients. The petrochemical ethylene oxide is required for ethoxylation, and this generates 1,4-Dioxane.

“This is a wake-up call for health-minded consumers across the U.S. who thought they were buying quality products at their natural food store,” said Ronnie Cummins, executive director of the Organic Consumers Association, a nationwide network of some 500,000 consumers of organic products. “There’s a lot of dishonest labeling going on out there.”

The study was commissioned and funded by the OCA, based on testing done at a California laboratory over a recent nine-month period. In conjunction with environmental health consumer advocate and author David Steinman, the OCA tested 100 popular products from major brands such as Aubrey Organics, Kiss My Face, Seventh Generation and Ecco Bella. Products ranged from shampoos and deodorant sticks to bath gels, baby bubble baths and all-purpose household cleaners. Items that came out as having no detectable 1,4-Dioxane included all those tested from Avalon Organics, Burt’s Bees, Desert Essence, Aubrey Organics and Dr. Bronner’s. But labels such as JASON, Giovanni, Kiss My Face and 365 — the private label from Whole Foods Market — had products found to contain varying degrees of the contaminant.

“My main objective was to give people information that was accountable and that would empower them to make smart choices,” said Steinman.

Brands contacted in the wake of the study said they would start reevaluating their formulas.

“We are concerned [by the report],” said Lisa Lehndorff, director of corporate consumer relations at the Hain Celestial Group, which owns brands such as JASON, Alba and Avalon Organics. “We are committed to providing our customers with the highest-quality, safest and effective personal care products, and, as such, are investigating these findings and reviewing our formulations accordingly.”