The Trump campaign claims to have used pepper balls, not tear gas, on protesters in Lafayette Square. What are they?

The effect of pepper balls on the senses lasted at least 24 times longer. Peaceful protesters adjacent to Lafayette Square can tell you this directly as the U.S. Park Police forcefully cleared the group, which it called violence, from the park and Trump's intended route of using chemical irritants.

Both eyewitness accounts and reports from the scene indicated that the U.S. Park Police used tear gas to clear the area. However, other agencies involved in the event, including the Secret Service and the Washington, D.C., National Guard, declined to say what ammunition was used. Both the Park Police and Trump's re-election campaign claimed it used smoke canisters and something called pepper balls, which were ultimately just a form of tear gas.

Pepper balls are very similar to paintball balls, but they are filled with an oily organic resin called capsicum oleoresin (or OC), which is derived from pepper. It's the same irritant used in pepper spray, in powder or liquid form. There is also a synthetic version, PAVA.

Although they're made from a different stimulant than tear gas, which is made from 2-chlorobenzamalononitrile (CS), according to the CDC, they're both riot control agents—in layman's terms, tear gas. I asked Chris Burbank, vice president of law enforcement strategy at the Center for Police Equity and former police chief, if the Trump campaign and the U.S. Park Police claimed they did not use tear gas to disperse protesters in Lafayette Square, for granted. Split hair - what they tell you is that we use chemical munitions to disperse crowds. You can get OC or CS, Burbank said. So it's like saying, "We hit this guy with a wooden stick," and then saying, "No, no, no, that's a metal baton." Either way, it's going to hurt.

How are pepper balls used?

The idea, Burbank said, is that you'll bump into people, the container will burst, and the powder will splatter on you. The wind won't disperse the powder in the pepper bullet as it fires tear gas from the canister and is usually used for large crowds, but it can still be picked up by the breeze and affect the person next to you. Officers are trained to target the lower center of gravity, or the middle of the chest or legs, said John Hodgson, director of the Center for Military Education and Training at Penn State's Applied Research Laboratory and interim deputy director of the center. For safety research and education to avoid hitting someone directly in the face.

In Indonesia in 2010, a protester was hit in the head with a pepper ball. [Photo: Achmad Ibrahim/AP/Shutterstock]

Why use them?

Pepper balls and other irritants are used to disperse or move crowds in the event of civil unrest, and authorities may use pepper balls instead of tear gas canisters, Hodgson said. In theory, he said, they could target specific people behind a crowd more accurately than tear gas canisters, which can only cover an entire crowd. It's also more controllable than tear gas canisters, which can be blown up by the wind, or things like buildings or bushes can catch fire, he said.

There must be vandalism or an active and fairly aggressive boycott to justify the use of pepper balls, Burbank said. He took issue with the Park Police's handling of protesters on Monday. According to Burbank, if the protests were peaceful, the fact that they were not moving would not justify the use of force. 'What I've seen is that a lot of people aren't necessarily going to do things that require that kind of power,' he said. This is very worrying because peaceful people do not deserve chemical munitions against them. He went on to say, if they block traffic, divert traffic. The police should protect free speech.

How dangerous are they?

The immediate effects of pepper balls are strong, and are similar to other chemical irritants: it causes your eyes to watery and a runny nose; it causes a cough and makes it hard to breathe. The length of time it affects your senses varies from 20 minutes to a maximum of 90 minutes—that is, after you leave the area and remove the substance from your body.

Hodges and Burbank say that if you get hit directly, it creates a paintball-like impact. It stings and can leave red welts, Burbank said. Both parties agreed that it was not a good experience. "I got hit a couple of times in training, and it wasn't fun," Hodges said.

When I asked Burbank about the relative dangers of pepper balls versus other non-lethal tactics used against protesters, he lumped all chemical agents into the same category and placed rubber bullets on what he called the use of force continuum one level. Most officers said they would rather be electrocuted than pepper sprayed, he said. Taser is you handle it and it's over. OC [capsicum oleoresin, the organic resin in pepper balls] lasts a long time.