Can a civilian use tear gas to disperse a mob of protestors gathered around his/her car?
<p>Let's say I'm driving down a major interstate highway and I see a group of ~100 or so people climbing over the highway fence and spilling out onto the highway. They have signs, I'm going to assume they're protestors. I bring my vehicle to a stop. Half an hour goes by, and the protestors are still blocking the road. </p>

<p>I lose my patience and start yelling inflammatory comments out the window ("Get the f*ck out of the road!"). The protestors surround my car and start banging on the windows/car. I'm getting anxious.</p>

<p>My car happens to be equipped with a tear gas release system which can blast a cone of tear gas through the front of the car. I have a gas mask. Aside from my car smelling terrible for a few days, what are the (legal) consequences of deploying said system in an attempt to get the protestors off my car?</p>

<p>You have to pick a jurisdiction: I pick California. <a href="https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=PEN&amp;sectionNum=22810." rel="nofollow noreferrer">Cal. Penal 22810</a> says that</p>

<blockquote>
  <p>Notwithstanding any other provision of law, any person may purchase,
  possess, or use tear gas or any tear gas weapon for the projection or
  release of tear gas if the tear gas or tear gas weapon is used solely
  for self-defense purposes, subject to the following requirements</p>
</blockquote>

<p>The list of requirements that follow include not being a felon, drug addict or minor. It has to be under 2.5 ounces and dispensed as spray, and if you use it for purposes other than self defense, it is a crime in its own right. Your description of the delivery system is not explicit enough that we can guess whether this is an "aerosol spray", so I will assume it is.</p>

<p>Is it justified as self defense? <a href="https://www.justia.com/criminal/docs/calcrim/3400/3470/" rel="nofollow noreferrer">This will tell you</a>. I assume based on your description that you have a reasonable belief that you are in imminent danger of bodily harm. You did not use excess force. You are not required to retreat. But <a href="https://www.justia.com/criminal/docs/calcrim/3400/3471/" rel="nofollow noreferrer">this also is relevant</a>: by insulting the protestors, have you lost your right to self defense?
Did you provoke a fight intending to create an excuse to use force? If so, you don't have the right to self defense. Telling a person to get out of your way is not generally held to be assault or initiating a fight, and doesn't fall in the category of "threat", but throwing the first punch is. Given the circumstances as described (and interpreted most favorably to you), you would be allowed to use tear gas in self defense. </p>

self-defense