We don't know how much extra credit they received, but hopefully it was worth it.

A class of Barberton High School students voluntarily signed up to be pepper sprayed for extra credit.

The result? A video of the experiment that's gone viral.

The students lined up outside Monday and a teacher sprayed them in the face one-by-one as a Barberton police officer stood by and watched.

Many of the students began screaming as the pepper spray took effect. Some doubled over and at least one can be seen on the ground.

Parents signed a waiver sent by the Barberton police chief to allow their students to participate in the activity, which was for a criminal science technology class.

Thousands have viewed the video, which has made its way onto several sites, including TODAY, Mashable and Daily Mail.

Watch the video below: