Should Bioplastics Be Allowed in Organic Compost?

Ela knows first-hand how central compost is to his organic farm—and all organic agriculture. It helps increase yields and the nutrient content of crops, reduce synthetic fertilizer use, and improve soil health and water retention, among other benefits. But he’s concerned that a new proposal to rewrite U.S. Department of Agriculture (USDA) compost rules could dramatically change the meaning of organic compost for farmers.

The USDA’s National Organic Program (NOP) currently requires compost to be derived from plant and animal materials, such as manure, food scraps, leaves, and straw. Newspapers or other recycled paper without colored inks are the only synthetic feedstocks allowed.

The proposal, filed by the nonprofit certification and advocacy organization Biodegradable Products Institute (BPI) in November, asks the USDA to allow synthetic, biodegradable food packaging and service ware as a feedstock for certified organic compost produced at commercial and municipal compost facilities.

The USDA’s National Organic Standards Board (NOSB), which guides the agency on standard setting, will decide at its biannual meeting on April 30 and May 1 whether to grant the change. BPI’s request is sparking yet another heated debate in a long, contentious history about what can and should qualify as organic under USDA’s program.

“The whole purpose of organics was to limit the number of synthetics used in agriculture,” Ela, a former NOSB chair who works part-time for the National Organic Coalition, told Civil Eats. “The only synthetics that are allowed to go through get pretty close scrutiny for environmental and human health and whether they’re actually needed.” He said that these materials don’t meet the USDA’s National Organic Program (NOP) standards, “as noble as the idea [of compostable packaging] is.”

Biodegradable food packaging and service ware—including cups, bowls, bottles, cutlery, and bags—is replacing traditional single-use plastics as companies seek to reduce their plastics use as well as the climate impacts of plastics derived from fossil fuels. By diverting food scraps and packaging to a composter and allowing it to degrade into a product that nourishes soil, experts say compostable food packaging also helps cut plastic pollution and methane gas emissions from landfills.

“We feel that there’s a lot of risks and not a lot of gain for us.”

The trouble is that compostable products are not necessarily more benign than the traditional plastics they are replacing: They can be made from plants such as corn, sugarcane or bamboo, and also from petroleum products. Though they are designed to fully break down under controlled conditions at an industrial composter, compostable products are nevertheless made with the same processes as conventional plastics, which means they contain many chemical fillers, additives, and dyes. Additionally, they can leave microplastics behind when they decompose.

Because not enough is known about how long biodegradable microplastics may linger in the ground and harm soil life, pollute waterways, or be taken up by plants, many organic farmers and commercial composters are calling for further scientific review or want to see NOSB reject the petition.

“We feel that there’s a lot of risks and not a lot of gain for us,” to accept compost derived in part from biodegradable packaging materials, Ela told Civil Eats.

In written comments to NOSB penned on behalf of the National Organics Coalition, Ela was more pointed. “Organic lands are not a dumping ground to get rid of problematic wastes,” he wrote. “The petition to include these materials is because manufacturers are looking for a way to easily dispose of these products . . . The reality is that the biggest issue is our societal embracement of single-use packaging.”

BPI’s Petition Motivated by California Law

BPI submitted the petition to the USDA on behalf of its members, who include composters, municipalities, and compostable product manufacturers, such as top bioplastics producers BASF, Eastman, Corbion, and NatureWorks.

The petition frames the move as advancing “climate-smart” agriculture by helping states, specifically California and Washington, achieve food-waste diversion goals. BPI states that the NOP’s current compost rules are an obstacle to states achieving their goals. “Composters are not able to market finished compost as an input to organic agriculture if they accept compostable packaging as a feedstock . . .”states the petition, adding that it’s a “major barrier for some composters, leading to decisions not to accept compostable packaging.”

In California, commercial composters sell 75 percent of their product to agriculture, and a significant portion goes to farmers who want organic compost even if they farm conventionally, said Neil Edgar, executive director of the California Compost Coalition, a lobbying organization that represents roughly half of the commercial composters in the state. Edgar has seen that California farmers “believe [organic compost] is a higher quality; that’s what they want, and in some cases, they’re contractually obligated with whoever their buyers are.”

But BPI is especially motivated by a provision in California law that would sunset the sale of compostable packaging not allowed by NOP on January 1, 2026. Such a ban would crimp the nascent compostable packaging market’s ability to grow. Compostable bioplastics are now a more expensive, niche product that comprise less than one percent of the $700 billion plastics market.  (The compostable market value is roughly $5 billion.)

Critics say BPI’s petition is designed to expand markets opportunities for its manufacturer members, without addressing the concerns of organic farmers.

“Without updating NOP’s compost rules, compostable packaging will be taken off the table by 2026, leaving food businesses without many sustainable packaging options.”

“The petition makes no argument that seems relevant to organic agriculture. It’s not even scientific. It’s a complaint,” Tom Gilbert, the owner of Black Dirt Farm, a small Vermont composter that takes plant-based fibers like egg cartons and coffee filters, but not compostable bioplastics, told Civil Eats.

Rhodes Yepsen, executive director at BPI, doesn’t deny that California’s deadline is driving BPI’s petition, but he says it’s about more than benefitting manufacturers.

“The organic industry has been an early adopter of compostable packaging, investing in research and development to launch these new materials, and proudly promoting the role it plays in their sustainability goals,” he said, naming food retailers PCC Community Markets and Oryana Coop, which are both members of NOC, and manufacturers Humble Chips and Sun and Swell. “Without updating NOP’s compost rules, the option of compostable packaging will be taken off the table by 2026 in California, leaving organic and conventional food businesses alike without many sustainable packaging options.”

Critics say further that BPI is seeking a significant change to organic compost rules without asking for technical review, which is “highly unusual,” according to Harriet Behar, a Wisconsin organic farmer and a former NOSB board chair. Petitioners typically ask for review by an outside scientific organization to determine whether their substance meets the criteria of the Organic Food Production Act, Behar told Civil Eats. But in this case, “[NOSB] is planning a vote without a technical review,” she said. “They’re getting a lot of pressure that this has to be answered quickly.”

Microplastics and PFAS Concerns

By ASTM standards, then, a material is considered compostable if any remaining material is not easily visible to the naked eye.

Field studies, such as a recent investigation by the Composting Consortium, show that by this measure, compostable products largely break down at commercial facilities. Microplastics could remain, however, and break down “very slowly, or not at all, outside of controlled conditions, such as in a farm field,” Ela wrote in his comments to the NOP.

Studies to date show mixed results. One study coordinated by the Fraunhofer Institute in Germany found that biodegradable bags contained large amounts of microplastics less than one millimeter in size that could remain in soil for a long time, and cautioned against widespread use of the bags without further research. Another study from Bayreuth University found that fertilizer from compost facilities contained large quantities of biodegradable plastics.

A meta-review of research by the University of Vermont found widespread microplastic contamination in compost materials though traditional plastic particles were more predominant than biodegradable plastic particles. “We have not typically observed compostable plastic particles in compost samples,” said Eric Roy, an associate professor of environmental sciences at the University of Vermont, who co-authored the meta-review and will soon be publishing original research on the topic.

Spanish researchers also found no debris less than five millimeters in size from biodegradable plastics in compost collected from different facilities, and they concluded that compostable materials were safe if composted correctly.

Such negative findings lead Yepsen to dismiss microplastic concerns. “We need to be realistic that microplastics in compost are a result of contamination from non-compostable plastic, and composting facilities receive contamination even if they don’t accept compostable packaging,” he told Civil Eats.

Roy, however, said that the jury is still out. Some studies do find biodegradable microplastics and more research is needed to understand how long the different types may linger in the environment and the potential harm they could cause to soil life.

“Theoretically, they will persist in the environment for a shorter amount of time than traditional plastics will,” he said, but there’s “some evidence that these materials are not necessarily entirely benign in the soil environment.” Biodegradable microplastics can affect soil stability and plant growth, and potentially release chemical additives, such as PFAS.

“Potentially, you could see alteration in the soil structure, which could alter water retention, or the suitability of the soil for key invertebrates like earthworms,” said, Richard Thompson, professor of marine biology and director of Plymouth University’s Marine Institute, who is lead researcher on a four-year investigation into the fate of biodegradable plastics in the environment.

BPI and other certifiers require products to pass additional tests for soil ecotoxicity as well as be PFAS-free. While that’s a step in the right direction, the soil ecotoxicity test “doesn’t capture everything that might be happening within the soil environment, such as effects on microbial communities or effects that take longer to manifest,” said Roy.

PFAS in food packaging has long concerned both composters and farmers: One study found that compost containing biodegradable food packaging contained PFAS levels up to 20 times higher than compost made from manure or from separated food waste mixed with grass clippings and livestock bedding.

“There is a long history of industry, food processing and municipalities using agricultural land as a place to get rid of their wastes.”

State laws banning PFAS from food contact materials and the Food and Drug Administration’s recent announcement that manufacturers will no longer use PFAS on fiber-based food packaging may begin to reduce contamination. Nevertheless, a certain level of unintentionally added PFAS is unavoidable, experts say, and the FDA has not eliminated PFAS on all food contact materials that may end up at a compost facility.

PFAS pollution on farm fields from sewage sludge is exactly why NOP should not allow compostable packaging as a compost feedstock, Ela said. “There is a long history of industry, food processing and municipalities using agricultural land as a place to get rid of their wastes,” he said, citing cheese making whey and recycled wallboard as well as sewage sludge. But “organic farms have been protected historically.”

Composters Are Wary

“If [fossil fuel-based plastics] can be replaced with bioplastics that have a reasonably sustainable footprint, that would be the ideal world, but we’re so far away from that,” Edgar said. Composters “deal every day with the reality of the material that’s coming in their gates and at this point in time, compostable plastics are just another single-use plastic that is clogging up the system and creating contamination.”

The U.S. Composting Council, a national trade, certification and advocacy group whose members include composters, government officials, researchers and compostable product manufacturers, declined to take a position in its written comments to NOSB on whether compostable packaging should be allowed in the NOP program, although it did support other changes to update the definition of compost.

“I think that this whole petition is an act of defensiveness,” Tom Gilbert, the owner of Black Dirt Farm, told Civil Eats.

Further Erosion of USDA Organic Standards

“Organic consumers don’t want PFAS or other chemicals in their food, and they expect that the organic farmer will be stewarding the organic lands,” agreed Behar.

While Roy understands that position, he said “there’s multiple reasonable perspectives” on the petition. “If we’re going to move toward a circular economy and recycle nutrients, it’s going to inevitably bring up some questions about how stringent should we be with some of these certifications.”

For Black Dirt Farm’s Gilbert, the willingness on the part of NOSB to advance the petition is why people feel increasingly disconnected from the organic standards. “Just look at what’s happened in poultry, allowing porches and other ridiculous exceptions that allow industrial operators to claim organic. The local foods and local economy movement is an antidote to that,” he added.

Ela agreed. “We’re trying to protect organic integrity and the value of the seal. The more we dilute that, the more we see people saying that it’s not worth it. That is the bottom line.”