Led by China, some importers are demanding new restrictions on residues contained in U.S. dairy products. The latest target is nonylphenol ethoxylates (NPE), a compound commonly used in the past in teat dips.

Earlier this year, China imposed a maximum NPE residue level of <10 parts per billion (pbb) in U.S. dairy products it imported. Almost 15% of U.S. dairy production now enters the export market, so any processor that sells – or hopes to sell – to the Chinese market is impacted. NPE concentrations are intensified as milk is evaporated to produce powder products, a popular form of U.S. dairy exports.

That growth in dairy exports markets, and since most processors have limited capability to segregate milk or dairy products within their facilities, forced several of them to institute a complete ban on the use of NPEs by their dairy farmer milk suppliers. Over the past few months, several cooperatives nationwide have sent letters asking their farmer members to switch to teat dips without NPEs.

What are NPE’s? According to Thomas C. Hemling, Ph.D., Global Manager of Research and Development for DeLaval Manufacturing, NPEs are surfactants which are widely used in the U.S. in industrial cleaning applications, including hard surface degreasers and laundry detergents. NPEs have been eliminated from many household product cleaning solutions over the past 20-30 years, primarily because of biodegradation and aquatic toxicity concerns.

On dairy farms, NPEs can be found in external surface cleaners and laundry detergents. There is minimal likelihood these applications would result in NPE residues in milk, Hemling said. It is more probable NPE residues result from clean-in-position (CIP) sanitation applications – although a majority of CIP detergents do not contain standard NPEs because they are high-foaming. NPEs have also been used in iodine teat disinfectants supplied by most teat dip manufactures in the U.S. market.

Despite their drawbacks – skin irritation – they are effective as a low-cost way to solubilize iodine. A 1% iodine teat dip product would typically contain 7%-10% NPE.

A concern raised by China is that NPEs may be endocrine disruptors. This relates to the chemical structure of nonylphenol, mimicking certain hormones similar to estrogen. The potential affects are greatest to infants and young children who consume the highest amounts of fluid milk.

While some brands of teat disinfectants have not used NPEs for over 30 years, the rest of the industry is actively recommending non-NPE alternatives, or reformulating their iodine products. In one Midwestern co-op, a field person checked the 20 farms supplying milk to its powder plant, finding just two herds using products containing NPEs. Both said their teat dip providers were discontinuing NPE as a teat dip ingredient.

Whether required by their dairy processor or not, dairy farmers may want to ask their teat dip supplier whether or not the product contains NPEs, and what the cost difference will be for a non-NPE product. The encouraging news, Hemling said, is U.S. dairy producers have viable options, including non-NPE teat dips already on the market. 

While NPE continues to be acceptable by both the U.S. Food & Drug Administration (FDA) and Environmental Protection Agency (EPA), with approvals for use in no-rinse CIP sanitizers, this restriction will seriously impact dairy farms. Consumer anxieties associated with NPE residues could affect a considerable portion of the U.S. dairy market, Hemling said.