From the Bolivian press, May 1936, this captioned photo illustrates the use of tear gas against American strikers during that turbulent period. The caption reads:

 This mask to protect against suffocating gases is not worn by a soldier nor by a militiaman, but rather a youth in North America on strike, who goes forth here well protected from the effects of teargas.

No further details are provided about the strike or the source of the image.