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Citadel News Service
19 Apr 2013

Cadet research finds "green" cleaning products may not be that green

Green consumer products are a billion dollar industry. Walk down the cleaning product aisle of any store and there is a dizzying array of green product options lining the shelves. Consumers are willing to pay more for these products because marketing suggests it is good to be environmentally sensitive.

But how green are these products, really?

Cadet Austin Gray worked with biology Professor and Department Chairman John Weinstein on research that examines the environmental safety of cleaning products marketed as green.

Research begun in biology Professor John Weinstein's lab in 2010 with funding from The Citadel Foundation took another step this year and it led Cadet Austin Gray, a health and wellness major from Charleston, to some interesting findings about the green claims made on cleaning product labels. These claims are largely unregulated and sometimes misleading because ingredients don't have to be listed if considered proprietary, Weinstein said.

Green products are better for the environment, right? Maybe. Maybe not.

A year ago, Gray, who is a senior, began investigating the toxicity of household cleaning products marketed as green. What he found is:

  • Some green products are more toxic than conventional cleaning products
  • When exposed to light the ingredients in green products break down, rendering them less toxic
  • Despite their claims, some green products are no less toxic for the environment than conventional products.

Gray's research "Does Degradation Alter the Toxicity of Green Household Products?" recently won second place in the student poster competition at the Carolinas Regional Society of Environmental Toxicology and Chemistry. He also won third place at The Citadel Undergraduate Research Conference for another poster based on the same work: "Toxicity of Green Household Products to the Freshwater Cladoceran, Daphnia magna."

"The fact that Austin was competing against both undergraduate and graduate students from some of the best toxicology programs in the nation, including Duke, North Carolina State and Clemson, speaks volumes about his dedication and commitment," said Weinstein.

Gray's research is a continuation of work that began when Jonte Miller was a cadet. Miller, a 2010 graduate of the Corps of Cadets and 2012 Citadel Graduate College alum, investigated the toxicity of green cleaning products using larvae of grass shrimp, which are native to the Lowcountry and very common in brackish water habitats. Miller wanted to know what happens when these products go down the drain, through the sewage treatment plant, then out to the harbor where grass shrimp live. He compared the toxicity of seven green products -- Seventh Generation Dishwashing Gel, Green Works All-Purpose Cleaner, Green Works Dish Detergent, Earth Options Insect Killer, Tom's Mouthwash, Martha Stewart Bathroom Cleaner, and Seventh Generation Laundry Detergent – to that of equivalent commercial products. Miller's research showed:

  • The green products were less toxic than conventional formulations in only two of the seven categories of household products tested
  • No difference in toxicity in three cases
  • One green product was more toxic than the tested conventional products.

In biodegradation experiments with activated sludge, none of the green products became less toxic but one product became more toxic. By contrast, the biodegradation treatment decreased toxicity of the conventional product formulations in eight cases, increased toxicity in five cases, and had no significant effect on toxicity in one case.

citadel_01888272_austinGray and Miller worked together on the research. This year Gray decided to work with a freshwater species that is commonly used in aquatic toxicity testing. Also, instead of a biodegradation treatment with sludge, Gray wanted to test a photo degradation treatment with simulated sunlight, Weinstein said. Using the same products Miller tested, Gray used water fleas (Daphnia magna) in four categories – laundry detergents, bathroom all-purpose cleaners, dish detergents and mouthwashes.

"What he found is that two of the green products were less toxic than conventional products," Weinstein said. "But, surprisingly, two of the green products were actually more toxic than at least one other conventional product."

Gray took his research one step further. He exposed all of the consumer products to a 30-day treatment under sunlight-simulating lamps in the laboratory to see if they became less toxic following photo degradation. His hypothesis was that when exposed to light, the ingredients in these products would break down, rendering them less toxic.

"Of the six green products tested, only three became less toxic following photo degradation," Gray said. "The toxicity of two green products didn't change, and, one green product actually became more toxic."

By comparison, seven of the eight conventional products tested became less toxic following photo degradation, he said.

The results suggest that, at least under these laboratory conditions, most green products didn't degrade any faster than conventional products. And some green products faired much worse in this treatment than conventional products.

What does all this potentially mean for the consumer?

"Buyer beware. Green product claims may be misleading and consumers may be making assumptions about green products that are not necessarily true," Gray said.

Gray will complete his research by the time he graduates May 4. He hopes to continue the work in graduate school, perhaps looking at the impact of plastics in the marine environment.

Gray has been accepted to graduate school at The Citadel and the University of South Carolina. He also has applied to the Medical University of South Carolina.

"My work with Dr. Weinstein has given me the opportunity to conduct research that brings awareness to the community about green products," he said. "I was also fortunate to have the opportunity to travel to conferences around the nation where I was able to learn from and be motivated by research professionals in the toxicology field."

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