Backgrounder: Nonylphenol ethoxylates (NPEs)

What are Nonylphenol ethoxylates?

Nonylphenol ethoxylates (NPEs) are a class of chemicals commonly used in industrial processes in pulp and paper and textile processing and in many other applications. Nonylphenol ethoxylates are not produced naturally. Their presence in the environment is solely a consequence of human activity.

What are common uses of these substances?

Products that contain NPEs are used in many sectors, including textile and pulp and paper processing, steel manufacturing, oil and gas recovery and power generation. They can also be found in paints, resins and protective coatings, and pest control products.

NPEs are also used in cleaning products, degreasers and industrial detergents, as well as in several consumers products, such cosmetics, cleaners and paints.

A voluntary ban on the use of NPEs in household detergents has been in effect for several years in some European countries, although NPEs are still used in industrial detergents.

NPEs enter the environment primarily via industrial and municipal wastewater treatment plant effluents (liquid and sludge), but also by direct discharge. NPEs may also enter the environment from their application in pesticide formulations.

Why has NPE been found to be toxic to the environment?

NPEs break down into Nonylphenol (NP), which is more toxic than the NPEs. NP and other breakdown products of NPEs have been found in water, sediment, wastewater, sludge from municipal and industrial wastewater treatment plants, and soil on which the sludge has been spread.

Acute adverse effects from exposure to NPEs have been reported in invertebrates, fish, mammals and algae. Concentrations of nonylphenol as low as 0.017 mg/L (17 µg/L) have been shown to be lethal to winter flounder in 96 hour exposures. These substances are not found to be bioaccumulative, or to transfer up the food chain.

The scientific assessment found that nonylphenol and its ethoxylates are entering the environment in a quantity or concentration or under conditions that have or may have an immediate or long-term harmful effect on the environment or its biological diversity.

NPEs have also been identified as a possible endocrine disrupting substance, capable of interfering with the development and reproduction of fish and wildlife. However there is general agreement in the scientific community that additional testing and research on NPEs must be carried out to gain a full understanding of their effects on the environment, including their potential as an endocrine disrupting substance.

Why were NPEs only assessed for environmental toxicity and not human health?

The primary focus of the assessment was on more sensitive environmental organisms, which are exposed directly to discharges of NP/NPEs. There is a significant difference between the level of exposure which produced adverse effects in animals and the potential exposure of the general population to NP/NPEs from air, water and soil. As a result, exposure to NP/NPEs at these levels is not believed to be harmful to human health.

Exposures to NP/NPEs from some consumer products are believed to be higher, but these are based on worst-case assumptions regarding absorption through the skin. Additional research into the rate of absorption of these substances by the skin would permit more a accurate assessment of exposure to NP/NPEs from these products.

What are the next steps for the federal government to reduce the effects of NPEs in the environment?

Under the Canadian Environmental Protection Act, 1999 (CEPA), the federal government has two years to develop preventive or control measures for NPEs, and a further 18 months to finalize them.

A range of options is available to reduce or minimize releases of substances that are found to be toxic. They include regulatory and voluntary initiatives, economic measures, environmental quality or release guidelines, codes of practice and pollution prevention plans.

For more information please contact: Danie Dubé Environment Canada (819) 953-0356

Ron Newhook Health Canada (613) 957-9576