Certain household products marketed as “green” are actually more toxic to animals than equivalent non-green products, according to new research conducted by a Citadel professor and an undergraduate student.

Prof. John Weinstein, who teaches toxicology at the Citadel, worked with Cadet Austin Gray on a pair of posters that recently won third place at the Citadel Undergraduate Research Conference and second place at the Carolinas Regional Society of Environmental Toxicology and Chemistry conference. Weinstein and Gray used water fleas (Daphnia magna) in beakers with solutions of several green products. The experiments looked at toxicity — that is, the rate at which juvenile fleas died in the solution — and photo degradation — that is, the tendency to break down during exposure to sunlight, a desirable outcome for green products.

What they found was surprising. One poster compares green products’ toxicity to that of conventional products both before and after 30 days of photo degradation and shows the following:

• Before photo degradation, Seventh Generation laundry detergent was equally toxic to Tide and more toxic than Gain (In other words, Seventh Generation = Tide > Gain). After photo degradation, the results were the same.

• Before photo degradation, Greenworks all-purpose cleaner < Lysol

• Before photo degradation, Greenworks dish detergent < Joy = Dawn. After photo degradation, Greenworks

The poster included an image of a label from one of the green products that claims the product is “non-toxic” and “safe for your family and the environment.”

A second poster looked at the effects of photo degradation and found that seven out of eight conventional products showed a decrease in toxicity. But when they ran the same tests on six green products, only three showed a decrease in toxicity: Tom’s mouthwash, Martha Stewart bathroom cleaner, and Greenworks dish detergent. Two products, Seventh Generation laundry detergent and Greenworks all-purpose cleaner, stayed the same. One product, Raid Earth Options, actually increased in toxicity after exposure to sunlight.

“They market these products as green, and I think the consumers just assume that the manufacturers are on the up and up and their claims have been validated,” Weinstein says. The work of Weinstein and Gray addresses two of the 12 principles of green chemistry that have been recognized by the American Chemical Society: less hazardous chemical synthesis and design for degradation.

Gray is a Charleston native who attended West Ashley High School and is planning to attend graduate school at either the Citadel, the University of South Carolina, or the Medical University of South Carolina. He says the subject matter of his posters stood out at the conferences. “The green products always catch the attention of the judges and the audience because it’s such a new topic that people don’t really know about,” Gray says.

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