Nonylphenol Ethoxylates (NPE)

What are nonylphenol ethoxylates and what are they used for?

NPEs are non-ionic surfactants made by reacting a substance called nonylphenol with ethylene oxide. Because they are very effective at dissolving grease and dirt, cheap, and work well even in hard water, they were widely used in the past in detergents, industrial cleaners and textile and leather processing.

Today, in detergent formulas they have largely been replaced by more readily biodegradable non-ionic substances such as fatty alcohol ethoxylates and glucosides.

Which products may contain it?

• Industrial cleaners with older formulas or from outside the EU
• Some cheap detergents that are imported or poorly labelled
• Processing chemicals used in textile manufacturing (as residues in clothing)
• Some paints, pesticides and industrial formulations

On the label it may appear as "nonylphenol ethoxylate", "NPE" or "nonoxynol". Many detergent labels, however, just say "non-ionic surfactants"; this general term does not on its own mean NPE, and today it mostly refers to safer alternatives.

Is it harmful? The scientific assessment

NPEs themselves are also harmful to aquatic organisms, but the main concern is that they break down into nonylphenol in wastewater and treatment plants. Nonylphenol is persistent in water and sediment, can accumulate in living organisms and, by mimicking the hormone oestrogen, can affect the reproduction of aquatic organisms such as fish.

For this reason, under REACH in the EU nonylphenol has been identified as a substance of very high concern (SVHC) because of its endocrine-disrupting properties for the environment. The use of nonylphenol and its ethoxylates at concentrations above 0.1% in detergents and many cleaning applications is restricted in the EU; there is also a separate restriction covering residues in imported textiles.

For the user, brief contact with a diluted product stays at the level of skin and eye irritation. The evidence on endocrine-disrupting effects on human health is not as clear as for the environmental effects; however, regulators take the view that exposure should be kept to a minimum because of persistence and aquatic toxicity.

What to do when you see it on a label

• For household cleaning, you can choose NPE-free products with a clearly written ingredient list.
• Be cautious with cheap industrial products that have no ingredient information or are labelled only in a foreign language.
• Washing new textiles before first use helps reduce chemical residues left over from manufacturing.
• Instead of pouring large amounts of leftover product down the drain, dispose of it according to local waste collection rules.

Readily biodegradable alternatives that offer similar cleaning power include glucosides such as coco glucoside and LAS, which is widely used in detergents.