After the Rinse: Hand Soap Biodegradability and Aquatic Toxicity

When selecting a hand soap or hand hygiene product, it is important to consider not just the product’s effectiveness and safety, but also how it will interact with the environment once it has been rinsed down the drain. After all, hand hygiene products are typically used at or around a sink and then immediately rinsed down the drain. Few users or purchasers ever consider what actually happens to the chemicals once they are washed down the drain.

Waste Cycle Summary

Waste water from household and institutional sinks, referred to as grey water, is typically transported to a sewage treatment plant through a series of municipal pipelines. Once at the sewage treatment plant, a series of physical, biological, and chemical processes are conducted to clean and decontaminate the water so that it can be safely disposed of back into a river, bay, or wetland. The same types of processes are conducted on the solid waste so that it can be safely disposed of or reused generally as farm fertilizer. However, chemicals from household products and hand hygiene products are often not completely removed from the process. This results in environmental contamination in oceans and on land which has negative effects on animals, humans, and the food supply of both.

Environmental Claims…Prove It!

As consumers and institutional buyers have become more and more interested in environmentally-conscious choices, marketers of consumer products and hand hygiene products have responded by making more environmental claims, such as “biodegradable” and “non-toxic”.

The term “Biodegradable” relates to the biological decomposition of material back into naturally occurring elements.

The term “Non-toxic”, from an environmental perspective for a hand hygiene product rinsed down the drain, indicates that it does not kill aquatic life.

Unfortunately, many of these claims are undefined, untrue, and/or unsubstantiated. Third-party environmental certifications are now available to assist purchasers in decision making, however without mandatory governmental testing and enforcement action, the responsibility of claim verification falls on the shoulders of purchasers. In other words, it is the responsibility of the purchaser to ask product manufacturers to “Prove it.”

Formulation Impact and Testing

Not all hand soaps and hand hygiene products, or their component ingredients are biodegradable and non-toxic to aquatic life, and it is important for purchasers to understand what to look for and avoid when evaluating a product. Below are a few things for purchasers to consider when selecting a hand hygiene product that is both safe and ecologically friendly:

Ingredients to Avoid:

Triclosan and triclocarbon: Of concern are the two common antibacterial chemicals triclosan (TCS) and triclocarbon (TCC). These chemicals have been linked to harmful effects in both humans and the environment. Arizona State University scientist Rolf Halden, PhD, estimates that every year Americans deposit more than one million pounds of TCS and TCC into the environment. Only half of all disposed triclosan and less than 25% of all triclocarbon is captured by wastewater treatment, and the remaining chemicals find their way into surface water sources and municipal sludge (a byproduct of the sewage treatment). The triclosan and triclocarbon that enters into rivers, lakes, and oceans is highly toxic to aquatic life and can remain in waterways for several years. In a nationwide assessment, researchers at Johns Hopkins University detected the presence of triclosan in 60% of examined waterways. Furthermore, U.S. farmers regularly use municipal sludge as fertilizer, allowing the TCS and TCC to potentially enter the food source. In fact, it is estimated that as much as 200 tons of triclosan and triclocarbon are applied to U.S. fields each year.

Request Data

In the absence of third-party environmental certification, it is important to explicitly request test data from a manufacturer to verify biodegradability and non-toxic claims. Some manufacturers make claims based only upon a cursory review of the component ingredients. Be sure that the test data relates to the final, full product formulation as the interaction of component ingredients and their collective impact on the environmental is most relevant.

To substantiate claims of biodegradable or readily biodegradable, look for the following test methodologies:

• OECD 301A-301E: OECD Guidelines for the Testing of Chemicals

To substantiate claims of non-toxic to aquatic life, look for the following test methodologies:

• ASTM D5660-96 (2004), “Standard Test Method for Assessing the Microbial Detoxification of Chemically Contaminated Water and Soil Using a Toxicity Test with a Luminescent Marine Bacterium”, 2004
• ISO 11348-1:2007, “Water quality – Determination of the inhibitory effect of water samples on the light emission of Vibrio fischeri (Luminescent bacteria test) – Part 1: Method using freshly prepared bacteria”, International Organization for Standardization, 2007
• Report EPS 1/RM/24, “Biological Test Method: Toxicity Test Using Luminescent Bacteria Photobacterium phosphoreum” Environment Canada, 1992

Purchasers should also thoroughly review a product Material Data Safety Sheets in order to fully understand all hazardous, handling, and safety declarations.

The B4 Brands Biodegradability Policy

B4 Brands understands the environmental risks and impacts of component ingredients and final formulations of hand hygiene products and has created policies, such as those below, to guide its product development and marketing:

• A strict prohibition on the use of triclosan and triclocarban in all Eco-Premium™ line products
• All claims of biodegradability and non-toxic to aquatic life are fully substantiated by third-party testing on final formulations

Summary

As has been discussed, many hand soaps and sanitizers are made with ingredients that are environmentally hazardous, non-biodegradable and toxic to aquatic life. When selecting a product, it is important for institutional purchasers to understand the implications of those ingredients and to take into account the importance of environmental safety and sustainability. Optimal decision making for institutional purchasers of hand hygiene products requires that manufacturers be required to provide sufficient data to substantiate all environmental claims. Institutional purchasers should simply ask manufacturers to “Prove it.”