The EPA wants to limit the use of formaldehyde in urea fertilizers

The EPA wants to limit the use of formaldehyde in urea fertilizers

Formaldehyde is an essential ingredient in the production of urea fertilizer, but setting the Environmental Protection Agency’s occupational exposure limit for the substance could jeopardize its use in agriculture. In March 2024, EPA published a draft Toxic Substances Control Act risk assessment for formaldehyde for public comment and peer review.

The EPA preliminarily determined that formaldehyde poses a disproportionate risk to human health. The EPA has not yet established a broad OEV for formaldehyde. If this EPA assessment is approved, formaldehyde restrictions or a ban on the substance could pose challenges for farmers.

Formaldehyde is a naturally occurring substance consisting of carbon, hydrogen and oxygen. According to the American Chemistry Council, humans produce about 1.5 ounces of formaldehyde gas every day due to their metabolism. Formaldehyde is also formed during combustion and is produced on a large scale by catalytic vapor phase oxidation of methanol.

Formaldehyde is often associated with the embalming process, but is also used in a variety of products including building materials, adhesives, fungicides, germicides, vaccines, household products, and urea fertilizers. The EPA classifies formaldehyde as “probably carcinogenic to humans” and a “high priority chemical,” so the agency can regulate its use.

Formaldehyde in fertilizer

Reagan Giesenschlag, director of government affairs at the Fertilizer Institute, called formaldehyde an essential building block in organic chemistry that is widely used in manufacturing. In the fertilizer industry, formaldehyde is used as a conditioning agent for granulating solid urea, slow-release urea and liquid slow-release urea-triazone fertilizers.

“It is important for us to granulate urea with a hardness and size comparable to the other P and K nutrients so that we can mix it and only have to do one application in the fields. said Giesenschlag.

Giesenschlag said before the use of formaldehyde-based reactants, urea was soft, powdery and produced dust, making it difficult to transport and handle when applied to a field. The U.S. Department of Agriculture conducted research that showed formaldehyde to be an ideal conditioning agent for urea and became popular beginning in the mid-1960s.

“We have been using this technology for a long time and it has enabled urea to be used more widely in agriculture as a source of nitrogen,” Giesenschlag said. “Urea is the highest content solid form of nitrogen we have. We currently have no viable alternatives to formaldehyde in the urea granulation process.”

For comparison, Giesenschlag said urea makes up about 25 to 30% of the nitrogen used in the United States. Globally, urea accounts for about 50% of the nitrogen used worldwide and the United States produces about 55% of the urea used domestically.

“In 1981, there was about 5 million tons of urea produced here in the U.S., today it is about 8.5 million tons,” she said.

To produce urea, Giesenschlag says small amounts of formaldehyde-based reactants are introduced into the reactor along with molten urea, allowing longer-chain molecules to be granulated into hard, uniform particles. The urea combines with the formaldehyde and completely converts it into new chemical structures. This process uses up all of the formaldehyde.

“The end products that our farmers or agricultural dealers process do not contain any free formaldehyde,” said Giesenschlag.

Giesenschlag said urea-formaldehyde fertilizers are safe and easy for farmers to apply to their fields and require no specialized equipment, making it a valuable fertilizer product for agriculture.

EPA’s proposal and potential impacts

In the risk assessment for formaldehyde, the EPA published a recommendation of an OEV of 11 parts per billion.

“That’s less than 50% of households in the U.S. and lower than background levels in many situations,” Giesenschlag said. “It is also around 30 times lower than the European Union’s recently revised formaldehyde standard. When the EU revised its risk assessment for formaldehyde and occupational exposure, regulators found no risk to end-users of fertilizers.”

Giesenschlag called the proposal unrealistic and too conservative. She said the EPA assessment was even more problematic considering that the EU has historically pursued much stricter chemical restrictions than the US. Although both parties had access to the same scientific and health studies, they came to opposite conclusions.

To illustrate, the average lethal dose of formaldehyde in humans is 600 to 800 milligrams per kilogram of body weight. In comparison, the average lethal dose of caffeine for humans is 150 to 200 milligrams per kilogram of body weight.

“When they (EPA regulators) complete the assessment, they will have one year to submit a risk management rule for all of these risk determinations,” Giesenschlag said. “If the inadequate risk assessment for the use of urea in the workplace is maintained, this would need to be included in risk management and subject to a potential ban or workplace chemical protection program.”

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Giesenschlag said a protection plan could include respirators or full face masks for anyone who works in agricultural retail or farmers who handle fertilizer. The potential consequences of formaldehyde restrictions in agriculture include general nitrogen shortages, reduced crop yields and higher food prices.

“We are concerned that maintaining inadequate risk provisions for the fertilizer industry could harm our ability to produce urea domestically,” Giesenschlag said.

Giesenschlag said the U.S. imports 45% of its domestic urea, mostly from countries such as Russia, Saudi Arabia, Algeria and Qatar. Formaldehyde restrictions could lead to farmers becoming dependent on these countries, increasing demand and therefore price.

“We don’t want to be dependent on imports from countries like Russia and we don’t want overly strict workplace standards imposed on farmers when there is no real risk to them,” Giesenschlag said. “Many of the assumptions the EPA has made about our industry and the chemistry surrounding fertilizer products are completely wrong. We were shocked by the inadequate risk assessment for the actual end products themselves. We have attempted to correct their flawed assumptions, but given the rush they are in to complete this by the end of the year, it is unlikely that we will do so in the final risk assessment will see a lot of changes.”

Giesenschlag said if the EPA’s recommendations are adopted, litigation is an option, but there will be many challenges to overcoming the EPA’s decisions.

“We participate in the process and try to provide them with the best information so that they don’t enforce these unreasonable regulations,” she said.

Lacey Vilhauer can be reached at 620-227-1871 or [email protected].