chloropicrin Archives

April 25, 2024

Postcard from California: State emits more of an obscure climate-heating gas than the entire rest of the US

By Bill Walker

Among US states, California is a leader in efforts to cut emissions of the greenhouse gases that fuel the climate crisis. But just three counties in Southern California emit far more of one little-known greenhouse gas than all other US states combined.

Blame termites – and the tragic, too-frequent mistake of replacing one environmentally harmful chemical with another that turns out to be just as bad.

Sulfuryl fluoride is a fumigant pesticide first made by Dow Chemical Co., marketed since 1959 as Vikane. To kill western drywood termites, pest control companies cover infested houses with tents and then pump in Vikane. Houses tented for fumigation are a common sight in Southern California, where warm, dry weather leaves wooden buildings highly susceptible to infestations of the hard-to-exterminate species.

The colorless, odorless, highly neurotoxic gas that kills termites is also a danger to humans. That’s why Vikane must be spiked with another toxic pesticide gas called chloropicrin, which has an intensely irritating smell that is meant to warn people against entering a house until the fumigant has dispersed in 24 to 72 hours.

California Department of Pesticide Regulation (DPR) records show that between 1992 and 2017, at least 16 Californians died from sulfuryl fluoride poisoning after going inside fumigated houses too soon. In the same period DPR recorded more than 200 cases of human exposure that caused breathing problems, dizziness, nausea, and other symptoms.

But the biggest problem with Vikane is that, when fumigation tents are removed and sulfuryl fluoride disperses into the atmosphere, it is a greenhouse gas much more powerful than carbon dioxide (CO2).

January 19, 2023

Report finds “vicious cycle” between pesticide dependence and climate change

By Shannon Kelleher

Pesticide use is a significant factor in harmful climate change, contributing to greenhouse gas emissions in multiple ways, according to a report issued this week.

The report released by the Pesticide Action Network (PAN) North America found that greenhouse gases are emitted during production of these pesticides as well as when they are applied to crops, and later on, as they linger in the soil. In turn, climate change creates conditions that lead to greater pesticide use, creating a vicious cycle.

“Some pesticides themselves are powerful greenhouse gases,” Margaret Reeves, a senior scientist at PAN North America in California and an author of the report, said during the webinar announcing the report.

Reeves cited a pesticide called sulfuryl fluoride as an example. The fumigant has nearly 5,000 times the potency of carbon dioxide, and in 2018 alone, three million pounds of sulfuryl fluoride were applied in California for agricultural purposes, Reeves said.

A 2021 study found that sulfuryl fluoride remains in the atmosphere for about 36 years.

Last year environmental groups filed a petition urging the California Air Resources Board to phase out sulfuryl fluoride due to its impact on climate change, arguing that phasing out sulfuryl fluoride would provide the same climate benefits as taking 1 million cars off US roads each year.

Reeves said many pesticides also release volatile organic compounds (VOCs), which react with nitrous oxide to produce ground-level ozone, a greenhouse gas that harms human lungs and burns plant tissue. The US Department of Agriculture has found that ozone may damage plants more than all other air pollutants combined.

Synthetic pesticides are, in essence, petrochemicals, and the fossil fuel industry and pesticides are inextricably linked, according to Asha Sharma, organizing co-director for PAN North America in California and an author of the report.

“We can’t address climate without addressing the dependency that conventional agriculture has on fossil fuels and pesticides,” she said.