The scoop on organic fertilizer

by Duff Wilson

This article was originally published in March 2003


(March 2003) — Editor’s note: When you buy compost or fertilizer this spring, understand that lawn and garden products labeled “organic” or “100 percent natural” may not comply with National Organic Standards. The National Organic Standards do not regulate the use of the term “organic” for commercial fertilizer and soil amendments. Use of the term “organic” on these products means only that the product is carbon-based. Use of the term “100 percent natural” means that the product is not synthetic. Washington State’s Department of Agriculture (WSDA), however, does keep a list of products “approved for use in organic food production.” These distinctions undoubtedly confuse consumers.

Some “organic” fertilizers contain undisclosed hazardous chemicals from industry waste, mining or other contaminated sources. While Washington is ahead of other states in testing for these “tag-along toxics,” it’s still extremely difficult for consumers to learn what — in addition to the advertised nutrients — is in the plant food they’re buying.

The practice of recycling toxic waste through fertilizer is not considered a part of sustainable agriculture. Indeed, tests of more than 2,000 registered products show that “organic” or “natural” fertilizers are often purer than many synthetic products.

Yet some industry ashes and mining wastes are repackaged and sold as “organic” fertilizers and soil amendments for food crops, lawns and gardens across the country. The industry saves money, but consumers aren’t told about the hidden ingredients.

Washington, Oregon, California and Texas have limited the hidden toxic ingredients in fertilizer, but other states haven’t.

No state requires truth-in-packaging on the fertilizer box or bag. Thus, the fertilizer loophole — a lack of standards, testing or disclosure of non-nutrient chemicals — applies to “natural” products, too. Some soil amendments labeled “organic” may still contain hazardous chemicals from industry waste or mining, just as synthetic products.

The loophole is that fertilizer-makers only list — and regulators only check — the advertised ingredients. You’re guaranteed a certain level of nitrogen, phosphorous, iron and zinc. But what else is in the bag? In most states, nobody controls it and nobody tells consumers.

The practice of recycling toxic waste into fertilizer has grown since America clamped down on hazardous waste in the late 1970s, raising costs and liability in landfills. The worst wastes — from steel works, electronic makers, industrial chemical makers, coating and engraving services, secondary smelters and refineries — aren’t supposed to go into “organic” products.

But some “organic” yard and garden products contain elevated, unadvertised levels of toxic chemicals from mining waste, wood or coal ash, pulp residue, fish parts, limestone substitutes, and natural rock phosphate from Idaho. Rock phosphate is not a waste but may contain high levels of arsenic, lead and cadmium.

Cadmium is an especially insidious chemical in the fertilizer loophole. It is readily absorbed by some plants, particularly leafy vegetables, and doesn’t hurt the plants, but it builds up in animals.

One Idaho company, Soda Springs Phos- phate, paid Monsanto a nominal $10 a ton for waste rock phosphate, ground it up, added a liquid wood-products waste, rolled it into granules, and sold it as “100 percent organic fertilizer.” It was all carbon-based, but certainly not what consumers have come to expect as “organic.” Soda Springs Phosphate was so high in cadmium it was banned in Canada.

Other mining wastes show up in other organic fertilizers. Ironite, for example, “a natural soil supplement and fertilizer,” is made from a mountain of tailings at a former mine and proposed Superfund site in Arizona. It’s extremely high in arsenic and lead, although the makers of Ironite insist those chemicals are in a form not available to plants.

Sometimes products advertised as “100 percent natural” are made in part with recycled “organic” industrial waste. Every year nearly 600 coal and oil-fired power plants in this country produce more than 100 million tons of combustion wastes, such as ash, sludge and slag. About 25 million tons is sold to be made into cement, wallboard and fill. The rest is disposed, among other uses, in agricultural applications.

Organic farmers in Indiana and other places say they’ve been offered coal combustion waste as “organic” liming material. These wastes are very alkaline, so they make good liming substitutes, but when the liming wears off, the metals are absorbed by plants.

The Citizens Coal Council, Hoosier Environmental Council, and Clean Air Task Force report these wastes may contain concentrated levels of arsenic, mercury, chromium and cadmium that can damage the nervous system and other organs, especially in children.

The Environmental Protection Agency (EPA) recently rejected a proposal to disclose coal ash in the Toxics Release Inventory. Armond Cohen of the Clean Air Task Force says, “This hazardous waste is less regulated than household garbage.”

The so-called Bevill Amendment, passed by Congress in 1980, exempted most mining, coal and oil-combustion wastes from any regulation whatsoever under the hazardous waste laws. The EPA currently is taking public comments on whether it should remove this exemption and how it should handle Ironite. David Fagan of the EPA’s Office of Solid Waste says the mining industry is threatening to sue to keep the exemption. Even “organic” fish emulsion fertilizers may be problematic. They may contain mercury. When Wisconsin tested 29 fertilizers, only two failed interim safety standards. One of them was a fish emulsion fertilizer that exceeded the limit for mercury.

Once sprinkled on the soil, heavy metals tend to stay in the root zone. They don’t migrate down. They blow around in dust. They may be removed by plants, depending greatly on the soil and plant species, but lower pH — as a liming effect wears off — means more uptake in plants.

A field and greenhouse study released in 2002 by Shiou Kuo and other Washington State University soil scientists notes, “The transfer of (cadmium, lead, arsenic) or other heavy metals from soils to crops presents a risk to crop productivity and quality. Consumption of metal-contaminated edible parts of the crops is a risk to public health.”

Ken Cook, president of the Environmental Working Group (EWG), says the extent of the problem isn’t known. Effects aren’t obvious; they’re long-term and cumulative. In January, studies by the EWG, New York’s Mount Sinai Hospital and the federal Centers for Disease Control and Prevention found low levels of industrial and agricultural chemicals building up in Americans’ bodies, even those who try religiously to avoid synthetic chemicals in their diet.

Need for disclosure Fertilizer is just one path of toxic exposure, but a part with unusually lax regulations. It’s one of the last barely-regulated bulk commodities. The industry sells 60 million tons a year worldwide. Most fertilizer is beneficial, but it’s what you don’t know that can hurt you.

Tests of 2,350 products in 1999 and 2000 showed about two-thirds of them had higher levels of nine toxic chemicals than the natural level of soil. The nine chemicals are arsenic, cadmium, copper, lead, mercury, molybdenum, nickel, selenium and zinc.

Canada limits these nine metals in fertilizer; the United States does not. Australia and some European nations strictly limit cadmium in food crops; the U.S. does not.

There have been improvements since this practice was first described in my 1997 Seattle Times investigative series, “Fear in the Fields: How hazardous wastes become fertilizer,” and 2001 book, “Fateful Harvest.” The EPA closed a loophole for steel-mill waste, thanks to a suit by the Washington Toxics Coalition and Sierra Club. Some companies started buying cleaner raw materials.

But no federal agency wants to regulate fertilizers nationally, as Canada does. That’s left to states, and they’re heavily influenced by industry.

Four years ago, the fertilizer industry fought back a proposal by Gov. Gary Locke to put all fertilizer ingredients on the product label. Some in industry said it would scare consumers; others said there wasn’t enough room on the label. Scott’s Fertilizer, the leading home and garden company, said it would stop distributing products in this state rather than label up.

While four states have passed varied laws regulating tag-along toxics, Washington is the only one requiring disclosure of the nine toxic metals you won’t find advertised on any fertilizer bag. Consumers may check product-by-product toxic levels in a commercial-fertilizers database on an obscure Web site under the Department of Agriculture (see “More information” sidebar in this article).

The problem with toxic waste in fertilizer also should not be confused with safely recycled compost or manure. Unlike fertilizer, compost and manure are tested and regulated nationally and are rich in organic matter. “Organic matter,” writes U.S. Department of Agriculture scientist Rufus Chaney, an expert on food-chain toxicology, “provides reactive sites which bind metals and thereby limit metal mobility and make metals less bio-available to plants.”

How else can consumers decide what to use on gardens and farms? Personally, I watch out for lime substitutes, especially darker materials. I feel more comfortable with compost and manure because of their organic matrix. And I shop organic more than I used to.

But it’s still hard to be an informed consumer. Miles McEvoy, who heads up the Washington State Department of Agriculture’s Organic Certification program for foods, suggests referring to the Web site with a list of organic-approved fertilizers (see sidebar on page 5). McEvoy says the Web site lists by brand name various fertilizers, composts and soil amendments that are “approved under the WSDA organic food program.” This means the approved products are acceptable for use on certified organic food crops. Some rock phosphates however, are still high in unadvertised toxics.

Most people can’t take their Internet connection to the store to compare products. I wish there was better labeling on the bags so consumers could make informed choices at the store.

Roughly one-third of all fertilizers tested contain less than the background level naturally found in soil of the nine priority toxic chemicals. I think these products should get a Brown Label, meaning “cleaner than dirt.” That would make shopping easier.

Duff Wilson is a Seattle Times reporter and author of “Fateful Harvest” (Harper-Collins, 2001), winner of the Investigative Reporters and Editors Book Award. He also is a two-time finalist for a Pulitzer Prize. For more information, see

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