There's usually a delay factor of several seconds before a fuse ignites the caustic substance. The gas carries the crystals that irritate skin and mucous membranes, he said. Pepper spray acts in a similar fashion but is more of an inflammatory agent that causes temporary blindness. It's made from dried chili peppers, and police often spray it with a hand-held device that looks like a gun. Pepper spray has inflamed controversies in recent years as it has been implicated in allegations of police abuse and scores of deaths.
Some people have really bad reactions to it.
Sprayed and then placed face-down, people occasionally suffocate, Wilson said. The spray also can pose a problem to children, the elderly and people with medical conditions such as asthma. Wilson has assisted several attorneys in lawsuits over pepper spray but said such cases are on slippery ground after the 9th U.S. Circuit Court of Appeals said Humboldt County, Calif., sheriff's deputies were justified in using pepper spray on protesters who took over a congressman's office.