Author: Nina Hwang, MPH

It has always been clear to Green Seal that toxic substances such as methylene chloride and 1,4-dioxane have no place in the products used in homes, schools or workplaces – that’s why we have long prohibited these and a long list of other hazardous chemicals in our certified products. 

Growing consumer awareness of the health risks of methylene chloride and 1,4-dioxane, both of which are found in common household and personal care products, has begun to prompt action by the federal government, states and retailers.  It’s encouraging that regulation and market behavior are beginning to catch up with the science on these two toxins. However, setting regulations is a lengthy process, and consumers shouldn’t be expected to police hazardous substances in household products in the interim.  

Green Seal fills a critical market gap by taking a precautionary approach – purposefully setting requirements beyond those of the U.S. federal government to empower consumers to choose the safest products on today’s markets and reward the industry innovators who are moving the market to safer, healthier product chemistry. Let’s take a closer look at the two examples of hazardous chemicals that Green Seal has prohibited for decades in our certified products. 

Methylene Chloride

In 1993, when Green Seal first launched our standard for paints and coatings, methylene chloride was one of the first chemicals we prohibited. More recently, methylene chloride has made its way into headlines for all the wrong reasons. Earlier this year, two women sued the EPA to ban methylene chloride after their sons died from using products containing this chemical. 

This colorless liquid evaporates easily, and its vapors can be irritating to skin, eyes, and the respiratory tract. Exposure to very high concentrations, usually in areas with poor air ventilation, can result in unconsciousness and death.  Since 1980, there have been more than 60 reported accidental exposure deaths due to the use of paint strippers containing methylene chloride.  

As a member of a class of chemicals called organochlorides, methylene chloride is in the company of other known bad players, including vinyl chloride, the pesticide DDT, and polychlorinated biphenyls (PCBs). Methylene chloride continues to be used because it is an extremely effective solvent. This chemical is used in paint strippers and in the manufacturing processes for other products, including pesticides, plastics, and pharmaceuticals. Consumer products that contain methylene chloride include paint strippers, household cleaners, and acrylic adhesives used by hobbyists.

The European Union voted to ban the use of methylene chloride in paint strippers for consumers and most professionals in 2009, effective beginning in 2010. Almost a decade later, in 2017, the U.S. EPA proposed a similar ban in both consumer and commercial products. The final rulemaking was delayed until March of this year, when a scaled back version was passed, which only bans methylene chloride in consumer products. In the interim, several major retailers – including Walmart, Lowe’s, Home Depot and Amazon – committed to phasing out methylene chloride products due to consumer concerns.   

1,4 Dioxane

Green Seal doesn’t only prohibit harmful active ingredients from certified products – we also have strict requirements for any impurities and byproducts that may make their way into a finished product. 1,4-dioxane is a probable carcinogen that has also been prohibited from all Green Seal-certified products since 1993. 

Unlike methylene chloride, 1,4-dioxane does not play a role in chemical products. Rather, it is an unintended by-product of a common chemical reaction called ethoxylation. In this process, ethylene oxide reacts with any number of chemicals, including alcohols, phenols, and polyethylene glycols, to create surfactants and other chemicals. These surfactants are used in cleaning products, laundry detergent, and shampoos to remove dirt and stains. Ethoxylated ingredients are also added to cosmetics as thickeners, skin conditioning agents, and emulsifying agents. Because it is a by-product, manufacturers may not even know if their products contain trace amounts of 1,4-dioxane. 

Twenty-five years after Green Seal first acted to prohibit this chemical, state legislators are beginning to address growing consumer concern about 1,4-dioxane. California now requires that this chemical be disclosed if it is present in cleaning products, even as an impurity. The New York State legislature recently passed a bill limiting 1,4-dioxane to 1 part per million (0.0001%) in detergents and other cleaning products and California has announced plans to consider setting a threshold as well. 

Green Seal and Safer Alternatives

It can be challenging for manufacturers to find alternative substances that are safer for human health and the environment and that still perform to industry standards. Sometimes, in an effort to avoid one substance, the market moves toward regrettable substitutes: N-methylpyrrolidone (NMP), once widely used an alternative to methylene chloride, has its own toxicity issues and has also recently been banned for consumer use by the U.S. EPA and retailers. 

Similarly, manufacturers that want to replace ethoxylated surfactants in their products to eliminate 1,4-dioxane will need to carefully select safer alternatives. Filling in data gaps can prevent the unintentional introduction of a dioxane-free replacement with its own set of health and environmental hazards. 

Consumer demand will continue to drive market change and innovation, especially among market leaders. When you see Green Seal’s certification mark on a product, you can trust that we’ve screened that product against these and all other known hazardous chemicals, and that the alternatives are not known to have associated health and environmental risks.  And because we have strict performance requirements, you can rest assured that these alternatives will still work as you expect them to.