Even though tear gas is banned in warfare, United States law enforcement frequently uses it to manage protests. Tear gas is made up of different chemical compounds, but the exact chemicals and their concentration remains unknown, as there is no national regulation requiring manufacturers to disclose this information. However, existing studies demonstrate its harmful effects.
Tear gas works by activating pain receptors, which trigger automatic protective reactions such as coughing, crying and increased mucus production to get rid of the chemicals. Children are especially vulnerable because tear gas tends to settle near the ground. Furthermore, their thinner skin, more delicate tissues, and smaller airways make it harder for them to breathe if swelling or excess mucus occurs.
Based on a 2014 study, over 6,000 army recruits reported that after being exposed to tear gas in training, the chance of developing respiratory illnesses doubled. This is because tear gas can damage the lining of the eyes and airways, which may cause fluid buildup in the lungs and lead to respiratory problems. Certain groups, such as the elderly, smokers or people with asthma are at higher risk because of their preexisting conditions.
Tear gas has also shown to cause heart problems. In 2025, a study of 69 people exposed to tear gas at protests found that 29 percent showed signs of reduced blood flow to the heart, and one third of the exposed people had abnormal heart signals. These findings suggest that tear gas may reduce oxygen supply to the heart.
Tear gas may also have lasting effects on the reproductive system. In a study of 1,200 people, 83 percent experienced uterine cramping or irregular bleeding. Among 19 pregnant individuals exposed, 10 had miscarriages.
Despite these documented long-term effects, the U.S. government conducts very little research on the health effects of tear gas and provides almost no federal funding for such studies. In response, the Concord Academy community can take action by drafting letters to advocate for federal support and research funding.