Tear gas, known as a lachrymal agent (from the Latin lacrima, meaning “tear”), sometimes known as mace, is a chemical weapon that causes severe eye and respiratory pain, skin irritation, bleeding, and blindness. In the eye, it stimulates the nerves of the lacrimal gland to produce tears. Tear “gas” generally consists of aerosolized solid or liquid compounds (Bromo Acetone or Xylyl Bromide), not gas. Tear gas works by irritating mucous membranes in the eyes, nose, mouth and lungs. It causes crying, sneezing, coughing, difficulty breathing, pain in the eyes, and temporary blindness. With CS gas, symptoms of irritation typically appear after 20 to 60 seconds of exposure and commonly resolve within 30 minutes of leaving (or being removed from) the area. In case of a survey it was found that severe symptoms requiring medical evaluation were found in 6.8% of people. The most severe injuries were to the eyes (54%), respiratory system (32%) and skin (18%). The most severe injuries occurred in law enforcement training, intentionally incapacitating people, and law enforcement (whether of individuals or crowd control).
As with all non-lethal or less-lethal weapons, there is some risk of serious permanent injury or death when tear gas is used. This includes risks from being hit by tear gas cartridges that may cause severe bruising, loss of eyesight, or skull fracture, resulting in immediate death. A case of serious vascular injury from tear gas shells has also been reported from Iran, with high rates of associated nerve injury (44%) and amputation (17%), as well as instances of head injuries in young people.While the medical consequences of the gases themselves are typically limited to minor skin inflammation, delayed complications are also possible. People with pre existing respiratory conditions such as asthma are particularly at risk. They are likely to need medical attention and may sometimes require hospitalization or even ventilation support.Skin exposure to CS may cause chemical burns or induce allergic contact dermatitis. When people are hit at close range or are severely exposed, eye injuries involving scarring of the cornea can lead to a permanent loss in visual acuity. Frequent or high levels of exposure carry increased risks of respiratory illness.
There is no specific antidote to common tear gases. Getting clear of gas and into fresh air is the first line of action. Removing contaminated clothing and avoiding shared use of contaminated towels could help reduce skin reactions. Immediate removal of contact lenses has also been recommended, as they can retain particles. Once a person has been exposed, there are a variety of methods to remove as much chemical as possible and relieve symptoms. The standard first aid for burning solutions in the eye is irrigation (spraying or flushing out) with water. There are reports that water may increase pain from CS gas, but the balance of limited evidence currently suggests water or saline are the best options. Some evidence suggests that Diphoterine, a hypertonic amphoteric salt solution, a first aid product for chemical splashes, may help with ocular burns or chemicals in the eye.Bathing and washing the body vigorously with soap and water can remove particles that adhere to the skin. Clothes, shoes and accessories that come into contact with vapors must be washed well since all untreated particles can remain active for up to a week.Some advocate using fans or hair dryers to evaporate the spray, but this has not been shown to be better than washing out the eyes and it may spread contamination.Anticholinergics can work like some antihistamines as they reduce lacrymation and decrease salivation, acting as an antisialagogue, and for overall nose discomfort as they are used to treat allergic reactions in the nose (e.g., itching, runny nose, and sneezing).Oral analgesics may help relieve eye pain.Vinegar, petroleum jelly, milk and lemon juice solutions have also been used by activists. It is unclear how effective these remedies are. In particular, vinegar itself can burn the eyes and prolonged inhalation can also irritate the airways. Though vegetable oil and vinegar have also been reported as helping relieve burning caused by pepper spray, usage of baking soda or toothpaste, stating that they trap the particles emanating from the gas near the airways that are more feasible to inhale. A small trial of baby shampoo for washing out the eyes did not show any benefit. So it’s better to visit a medical professional rather than to try home remedies if you are exposed to tear gas.