Is acid rain coming down over Ohio farmlands? Social media posts claim this is an effect of the response to the Feb. 3 train derailment in East Palestine, Ohio.

A woman in a Feb. 19 Facebook video claimed that vinyl chloride carried on the train came “spewing” and “boiling” out of the tank cars, and that’s why responders had to burn the chemical. She instructed viewers to avoid drinking the water and to take topsoil samples.

Some of the train’s tank cars carried vinyl chloride; five of them derailed and posed a risk of explosion. To prevent this, responders conducted a controlled venting to release and burn the vinyl chloride. The woman in the video added: “What’s going on in Ohio is that there are 75,000 acres of farmland, fertile farmland, that are all now being poured down with acid rain.”

This post was flagged as part of Facebook’s efforts to combat false news and misinformation on its News Feed. (Read more about our partnership with Facebook.) The video was originally posted on TikTok Feb. 17.

So, is acid rain pouring down over Ohio because of the train’s derailment? We found no proof of that. Here’s what we know.

Vinyl chloride is a colorless gas used primarily to make polyvinyl chloride or PVC, one of the world’s most widely produced plastics. It is used in pipes, car parts and housewares. The Environmental Protection Agency said hydrogen chloride was released after the derailment during the controlled vinyl chloride burn.

Vinyl chloride in the air can form hydrogen chloride, which could be incorporated into cloud, rain and fog water, thus forming a component of acid rain. (The EPA said acid rain occurs when sulfur dioxide and nitrogen oxides are emitted into the atmosphere and transported by wind and air currents.)

Because wind can blow acid rain’s components over long distances, the chemical burn’s aftermath could have affected people and land far beyond the derailment site.

However, James Lee, an Ohio Environmental Protection Agency spokesperson, told USA Today that there has been no hydrochloric acid rain in Ohio. PolitiFact reached out to Lee, but he declined to comment.

And Ohio Department of Agriculture spokesperson Meghan Harshbarger told PolitiFact on Feb. 27 that the office had “no reason to believe the train derailment has caused acid rain to pour down on farmland.”

If the pollutants that cause acid rain — sulfur dioxide and nitrogen oxide — react in the atmosphere and form fine sulfate and nitrate particles that can be inhaled, they can cause, or worsen, respiratory diseases in people, the EPA said.

Acid rain can also harm fish and other wildlife. When acidic rainwater flows through soil, it can leach aluminum from soil clay particles and then flow into streams and lakes, where acid-sensitive plants and animals may live.

An increase in soil sulfur levels can also affect the uptake of minerals into herbage that can lead to ill health in livestock.

The Cincinnati Enquirer also reported on this claim Feb. 17. Kevin Crist, professor of chemical and biomolecular engineering and the director of the Air Quality Center at Ohio University, told The Enquirer that acid rain could have formed after the controlled release and burn of chemicals Feb. 6.

However, Crist also said that once the vinyl chloride stopped burning and once there was no longer a plume, it would “dissipate pretty quick.”

Jana Houser, associate professor of Ohio State University’s atmospheric science program, told PolitiFact that as soon as chemicals enter the atmosphere, they dilute as they mix with other atmospheric gases.

Houser plotted trajectories for how air molecules in and around the incident site could have traveled Feb. 3, when the train derailed, and Feb. 6, when the controlled burn began. She concluded that the likelihood of producing a toxic acid rain is “essentially nonexistent, especially not over Ohio.”

Houser also said that to have acid rain, there needs to be rain. Citing data from the Community Collaborative Rain, Hail and Snow Network, Houser said there was no rain in and around the derailment site from Feb. 3 to Feb. 8.

By the time light rain fell Feb. 8, most of the chemicals released in the Feb. 6 controlled venting would have been gone, Houser said.

As of Feb. 13, the Ohio Environmental Protection Agency discontinued air monitoring for hydrogen chloride, saying the threat of vinyl chloride fire-producing hydrogen chloride “no longer exists.”

Our ruling

A Facebook post claimed that In Ohio, “there are 75,000 acres of farmland, fertile farmland, that are all now being poured down with acid rain.”

The Ohio Department of Agriculture told PolitiFact it had no reason to believe the train derailment caused acid rain to pour down on farmland.

An atmospheric scientist plotted trajectories for how air molecules in and around the incident site could have traveled when the train derailed and when the controlled burn began, and concluded that the likelihood of toxic acid rain in Ohio was “essentially nonexistent.”

We rate this claim False.

This fact check was originally published by PolitiFact, which is part of the Poynter Institute. See the sources for this fact check here.