When a trucker picks up a load of gray, toxic ash from a metal-processing plant in California, he hangs a "hazardous waste" sign on his rig. On crossing the border into Nevada, he takes the sign down.
In that state, what he's carrying is no longer considered hazardous waste, but fertilizer ingredients. The waste will be delivered to a factory in Reno, treated to remove part of the heavy metals, blended with other materials and sold as fertilizer to farmers in, among other places, California.
Such is the fractured regulation of the fertilizer industry. Fertilizer -- unlike food, animal feed, pesticides, herbicides and sewage sludge -- is not controlled by federal law. To the degree it's regulated at all, it's on a state-by-state basis.
New York State has recently begun extensive testing of fertilizer sold here. The DEC looks for sewage sludge and the Agriculture Department does trace mineral testing and also monitors inert ingredients, according to State Agriculture Commissioner Donald Davidsen. Nothing suspect has turned up in the fertilizer here, he said.
But the lack of national regulation and of labeling requirements means most farmers have no idea exactly what they're putting on their crops when they apply fertilizers.
There's a limit on the amount of lead in a can of paint, but not in fertilizer. There's a limit on the amount of dioxin in a concrete highway barrier, but not in fertilizer.
If that same trucker tried to wheel that ash up Interstate 5, he could take off the hazardous-waste sign through Oregon and Washington, which both have less regulation than California.
But when he got to British Columbia, he'd be turned away at the border.
Canada and many European countries have stringent limits on toxic metals found in industrial byproducts. They refuse to buy products that, on American farms, routinely are sprinkled on the ground.
Some U.S. experts say those nations are less interested in science than in trade protectionism. These experts, working for government agencies and the fertilizer companies, say the products are safe and the process of recycling hazardous waste into fertilizer is good for America and Americans.
"It is irresponsible to create unnecessary limits that cost a hell of a lot of money," says Rufus Chaney of the Department of Agriculture's Research Service.
Canada's limit for heavy metals such as lead and cadmium in fertilizer is 10 to 90 times lower than the U.S. limit for metals in sewage sludge. The United States has no limit for metals in fertilizer.
Canada requires tests every six months for metals in recycled-waste fertilizer; the U.S., none.
"In the U.S., I hear them say, 'OK, how much can we apply until we get to the maximum people can stand?'" said Canada's top fertilizer regulator, Darlene Blair. "They're congratulating people for recycling things without understanding what the problems are with the recycled material."
In Canada, Blair said, "We're a little beyond the point where we wait till something is proved bad before we fix it. Sorry, but we won't compromise our health."
Some health and environmental experts are pushing for similar regulation in this country. But from Washington state to Washington, D.C., the fertilizer industry is waging a successful campaign against it.
The $15-billion-a-year business cultivates clout.
In Congress three years ago, lobbyists for the Fertilizer Institute won removal of a section of the proposed Lead Exposure Reduction Act that would have banned fertilizers with more than 0.1 percent lead.
Internal minutes of the institute, the industry's main lobbying group, show it wants to streamline hazardous-material laws and "manage the issue of regulation of heavy metals in fertilizers."
The industry also lobbies its own members to oppose fertilizer regulation.
The primary argument against labeling or regulating fertilizers with toxic wastes is that it would raise costs, both of waste disposal and food production.
"Agriculture is being used as a dumping ground," Smallwood said. "They get away with it because there's nobody watching, nobody testing. It's the lure of the dollar."
While all the substances in question occur in nature, science is finding there is no safe level for many of them.
In recent years, doctors and scientists learned that trace amounts of lead can cause developmental problems in children and high blood pressure in adults. Lead is prohibited in gasoline, paint and food-can solder, but not in fertilizer.
In fact, lead is in many fertilizers. It is never disclosed on the label, though, even when it is as high as 3 percent of the product.
As a result, farmers and orchardists are spreading up to one-third of a cup of lead per acre when they follow the manufacturers' recommendations. The farmers and orchardists aren't told about the lead, which has no nutrient value for plants.
Hazardous-waste recyclers say they could remove more lead, but it would cost more and make it harder to compete on price unless everybody had to do it.
Nobody really knows how much risk exists in waste-recycling programs that have sprouted since Congress passed the Resource Conservation and Recovery Act in 1976.
Every state has a fertilizer regulator. But they don't check for heavy metals even when they know the metals are included in the product. They only check for nutrients listed on the label.