A widely used pesticide found to pose health risks for children and wildlife is due to be phased out in Maryland next year, but the state’s lawmakers may still have the last word on making sure it’s done.

After two years of debate, the General Assembly finally overcame industry objections and passed legislation in March that would ban aerial spraying of chlorpyrifos by Oct. 1 and forbid all uses of it by the end of 2021. It was one of just a handful of environmental bills to pass in this year’s legislative session, which was cut short by the coronavirus pandemic.


Chlorpyrifos has been used since 1965 to prevent insect damage to crops, such as the soybeans shown here, but research has found that it can damage the health of children and wildlife.

But Gov. Larry Hogan last week vetoed the measure, saying the lawmakers’ action had been rendered moot by a Maryland Department of Agriculture regulation adopted shortly after their vote. Environmentalists disagree and want legislators to override the governor’s veto.

On the market since 1965, chlorpyrifos (pronounced klor-PEER-uf-foss) has been used to prevent insect damage to corn, soybeans and other crops. It’s also been used to treat golf courses, lawns and utility poles as well as to fog mosquitoes and to kill ants and roaches indoors.

Research has mounted, though, indicating it can damage the brains and nervous systems of young children and can harm bees, fish, birds and other wildlife.

After a lengthy study, the U.S. Environmental Protection Agency was preparing to ban it until the Trump administration blocked the move in 2017. That led environmentalists to sue and press states to ban it. In Maryland, legislation failed two years in a row amid pushback from farm groups, golf course owners and pesticide manufacturers, who argued that the chemical is needed and already restricted in use.

This year, state lawmakers moved early to enact the ban. Then Agriculture Secretary Joe Bartenfelder announced in February that his department was working on “reasonable and responsible regulations” to phase out chlorpyrifos. Environmentalists accused the administration of trying to torpedo the legislation. The department officially took no position on it, but the announcement came as lawmakers were preparing to vote on it. The state regulation, rushed through on an emergency basis, took effect March 27, just after lawmakers left Annapolis.

“This regulatory action is in the best interest of the agriculture industry and the environment,” Hogan said in a veto message to legislative leaders, “and will protect the independence and integrity of MDA's robust science-based regulatory authority and framework.”

The state regulation mostly mirrors the vetoed legislation. Both would forbid aerial spraying of chlorpyrifos on Oct. 1 and ban most other uses after Dec. 31. The pesticide could still be used to treat snap beans and fruit trees through June 30, 2021, and the agriculture secretary could extend that until the end of next year. 

State agriculture officials say the use of chlorpyrifos in Maryland has declined dramatically, and a leading U.S. manufacturer, Corteva Agriscience, will cease production in 2021. It is now mainly used to treat fruit trees, though some treated seeds are used to grow crops for canning, according to MDA spokesman Jason Schellhardt. 

But the state rule contains a catch-all exemption not in the legislation: The agriculture secretary can allow other unspecified uses of chlorpyrifos through the end of 2021. That would only be permitted “as an absolute last resort,” Schellhardt said, in cases where no other product is effective. 

The Smart on Pesticides Coalition, an umbrella group of community, environmental, faith and public health organizations, called Hogan’s veto “extremely misguided.” It contended that the state’s agriculture department lacks the funds or expertise to enforce or defend a regulatory ban on chlorpyrifos.

“MDA’s regulations would allow for delays, exemptions, and loopholes resulting in continued exposure of this toxic chemical,” the coalition said. “MDA could change its regulations at any time, and opponents could file lawsuits challenging the regulation.” 

Sen. Clarence Lam, a Howard County Democrat who was lead sponsor of the legislation, said the regulations are “not sufficient to protect the public from the harms of chlorpyrifos…It is important that the General Assembly overrides this veto when it is able to meet next.” 

Citing the need to limit spending amid budget gaps created by the coronavirus pandemic, Hogan also vetoed a bill that would have funded an effort to have Maryland’s universities and other state institutions buy more locally grown food. 

He allowed several other environmental bills to become law without his signature. Among them were measures prioritizing state funding for long-term farm runoff control practices, banning fire-fighting foam containing toxic per- and poly-fluoroalkyl substances (PFAS), expanding fisheries for invasive snakeheads and tweaking the state’s oyster management plan.

Tim Wheeler is the Bay Journal's associate editor and senior writer, based in Maryland. You can reach him at 410-409-3469 or twheeler@bayjournal.com.

(2) comments


What is the bill number for the pesticide ban?

Tim W Staff
Tim W


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