The US federal government uses CRC (capsaicin and related capsaicinoids) content for regulation. CRC is the pain-producing component of the OC that produces the burning sensation.
Personal pepper sprays can range from a low of 0.18% to a high of 3% Major Capsaicinoids. Most law enforcement issue pepper sprays use between 1.3% and 2%.
Dog and bear attack pepper sprays (the only allowed for use in Canada) for sale to the public in Canada contain no more than 0.50% Major Capsaicinoids, the maximum strength allowed by Health Canada for use or sale with the common amount being only 0.25 - 0.30%.