I've done a little research on pepper spray and found the following:
Occupational Health Services, Inc. reported that because OC caused the subject’s breathing passages to swell and constrict, the use of OC on persons with pre-existing respiratory conditions such as asthma could, in rare instances, cause death.
According to IACP pepper spray expert John Granfield: Most of the information on OC has come from officers who used it during training and on subject. This information has been basically anecdotal. A number of manufacturers, in order to protect themselves from liability, did contract with private labs to do tests. However, no government or consumer agencies have done any tests.
Scientific American said, the potentially lethal effects of pepper spray have been widely documented. For instance, in the 1990s, the Justice Department listed nearly 70 deaths it said were linked to the use of pepper-spray.
The ACLU pressed California's Supreme Court to classify pepper-spray as dangerous and cruel, likening it to "a kind of chemical cattle prod on nonviolent demonstrators resisting arrest." The organization further claimed that its use "constitutes excessive force and violates the Constitution."
Three deaths have occurred in California in which the use of such products by highly trained law enforcement personnel was involved, and one recent legal use in North Carolina resulted in the death of an apparent asthmatic. OEHHA is concerned that in each incident that untoward reactions to OC may have been a contributing cause of death or exacerbated underlying conditions such as asthma or drug use to cause cardiac or respiratory failure.
