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Report to the Deputy Attorney General on the Events at Waco, Texas: Appendix J. Riot Control Agent, CS Information Obtained from British and U.S. Studies

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Report to the Deputy Attorney General on the Events at Waco, Texas
February 28 to April 19, 1993

Appendix J. Riot Control Agent, CS Information Obtained from British and U.S. Studies



Effects of CS Exposure

  • British studies, over the course of a few years, and in "tens of thousands of military personnel" who have been exposed to CS in training, have been unable to determine any symptoms essentially different from those which have been determined in U.S. studies. These symptoms are as follows:

Effects of CS Overexposure (Overexposure is defined as any exposure that brings on any of the effects listed here)
















  1. Burning, pricking, peppery sensation in the eyes, nose, mouth, throat, and skin.
  2. Lacrimation - excessive secretion-of tears.
  3. Rhinorrhea - excessive mucous secretion from the nose.
  4. Salivation - produces excessive saliva.
  5. Blepharospasm - uncontrollable winking caused by involuntary contraction of eyelid muscle.
  6. Photophobia - abnormal intolerance of light (lasts less than one hour in 90% of subjects).
  7. Tightness of the chest associated with gripping pain.
  8. Breath holding - usually an attempt to defend against the effects - not a physical (involuntary) action.
  9. Dysphea - shortness of breath.
  10. Coughing and sneezing.
  11. Vesiculation -blistering, small (prolonged or repeated exposure).
  12. Erythema - redness of the skins caused by chemical poisoning or sunburn (prolonged or repeated exposure).
  13. First, and possibly second degree burns in sensitive people.
  14. Congestion of the nose-wall of the pharynx (section of the digestive tract from the oral cavity to the larynx).
  15. Feeling of suffocation.



  • All of these effects occur immediately and will persist 5-20 minutes after removal from a contaminated atmosphere.
  • Determination difficult due to differences in motivation and tolerance i.e.. Variability in humans.





    • In a case in Northern Ireland, a baby (no age given) was found crying in a bedroom that had been exposed to CS. The child was gasping for breath, tears were streaming down his cheeks and he was very pale. Upon removal from the affected room, the child recovered quickly.
    • The British found cases of babies exposed to CS, in sufficient quantities to distress them and to awaken them crying from their sleep. In all of these cases, upon being removed from the contaminated area, these babies all recovered rapidly. There are no reported cases requiring admission to hospitals, and no instances in which illness in previously healthy infants could be attributed to CS.
    • Contact with the U.S. Army Chemical Research and Development Center, Edgewood, Maryland, indicates that they know of no laboratory studies that have ever been conducted with CS that utilized children as subjects. This Army facility has data bases that contain virtually every study on CS that has been conducted by any government or private facility In the world.






    • The British have conducted studies on the effects of CS on the developing embryo. This study found that no Interference with embryonic development has been demonstrated.
    • Following the use of CS In Northern Ireland, there has been no Increase In the number of abortions, still-births or congenital abnormalities.
    • British studies conclude that there are no grounds for believing that inhalation of CS can cause malformation of an unborn fetus.
    • Experimental evidence indicates that CS does not interfere with the course of pregnancy.




    • British found no evidence of any special susceptibility to CS associated with old age. Effects on the elderly were reported, but these were in regard to exacerbations of previous ill health.
    • Human volunteers, of 50 years of age and upwards have been exposed to heavy concentrations of CS. The symptoms they experienced, and the time taken to recover from these, were no different than in young adults.




    • Food and drink contaminated even by traces of CS is so repulsive to the taste, that It could not be consumed inadvertently and, when it has been consumed voluntarily, no ill effects have followed.
    • British evidence Indicates that:

    • With the concentrations possible in riot situations, it would be in the highest degree unlikely that CS would cause liver damage. Further, if by any chance it did, it would be temporary and clear up in 2-3 weeks. ("mild and transient")


      • In experimental exposure of human subjects, no significant changes in liver function were detected.


      • In the worst case of exposure in Northern Ireland, liver function gave normal results when tested ten months later.


    • There is no evidence that CS acts as a carcinogen.
    • After CS exposure, no chromosome changes of any kind were found to-develop In the cells of healthy volunteers or persons who had been exposed to CS during the riots in Northern Ireland.







    • LCt 50 is the concentration of any chemical substance that will kill 50% of any given population. (Concentration = mg/m3)


      • The smallest trace of CS that a man can detect is about 0.004 mg/m3.
    • The concentration of CS that produces symptoms sufficiently unpleasant to cause people to leave an area Is 0.5 mg/m3.
    • The concentration that will deter trained troops is 10 mg/m3.
    • The concentration that has been estimated to be lethal to man is 52,000 mg/min3. This concentration, In the opinion of researchers, can only be attained in ideal laboratory conditions. Any concentration at this level, in relation to operational considerations, are essentially artificial.
    • Research has determined that a high concentration of CS for a short time is less toxic than a lower concentration for a long time.


    Updated February 14, 2018