The Environmental Protection Agency is reminding the public that the "chemtrails" conspiracy theory on aircraft emissions just isn't true.
Conspiracy theorists say that government officials or others are using jets to spray harmful chemicals into the atmosphere. They cite the contrails left by jets as evidence of the chemicals.
“Contrails are line-shaped clouds or ‘Condensation trails’ composed of ice particles that are visible behind jet aircraft engines under certain atmospheric conditions and at times can persist,” says the notice, posted to the EPA’s website Friday.
“EPA is not aware of any deliberate actions to release chemical or biological agents into the atmosphere.”
Theorists have posited that the chemicals are meant to control the climate, to harm humans or to kill them.
The fact sheet from the EPA and other federal agencies like the Federal Aviation Administration and the National Oceanic and Atmospheric Administration was first published in 2000, when the chemtrails conspiracy became popular on the Web.
An EPA spokeswoman said the agency frequently receives questions about chemtrails.
The information posted Friday is “nothing new,” the spokeswoman said, adding that the EPA posted the information to make it more readily available to the public.