The Science Behind Tear Gas Pain

The public has once again raised concerns over the police’s use of tear gas during a series of protests from August 25–31, 2025. The controversy stems from the fact that the tear gas was not only deployed to disperse protesters, but also spread into nearby residential areas.

In Indonesia, the use of tear gas is legally permitted. It is commonly employed as a crowd-control tool, regulated under the Chief of Indonesian National Police Regulation No. 1 of 2009.

However, its use continues to spark debate. The main issue is that tear gas deployed by security forces often spreads into civilian neighborhoods. In several documented cases, authorities have even used expired tear gas.

Tear gas is a chemical weapon designed to stimulate the tear glands, forcing the eyes to produce excessive tears. Because of this effect, it falls under the category of lachrymators (tear-inducing agents).

So, what is tear gas actually made of? apt. Ahmad Fauzi, S. Farm., M.Farm., a lecturer at the Faculty of Pharmacy, Universitas Muhammadiyah Surakarta (UMS), explained that tear gas is typically composed of two primary chemical agents

Tear gas contains chemical agents known as 2-chlorobenzylidene malononitrile (commonly called CS gas) and oleoresin capsicum (OC), better known as pepper spray.

“For current use, only these two chemical agents are globally permitted: CS gas and OC gas,” explained Fauzi on Thursday (3/9/2025).

Fauzi noted that the CS and OC components in tear gas cause eyes to redden and can trigger breathing difficulties. 

The effects on the human body can vary, generally grouped into two categories: local effects and systemic effects.

Local effects of tear gas include:

• Burning and watery eyes, with excessive tearing
• Temporary blurred vision
• Runny nose
• Itchy or irritated throat
• Coughing
• Shortness of breath
• Burning sensation on the skin
• Redness of the skin (erythema)
• Itching or blistering on moist areas of the skin (such as folds)

Meanwhile, the systemic effects of tear gas exposure include:

• Panic, anxiety, and disorientation
• Headache, nausea, and dizziness
• At high doses or in enclosed spaces, the risk of hypoxia (oxygen deprivation), which can lead to fainting or even be fatal

“These local effects typically last for about 30 minutes after exposure. However, the systemic effects can be worsened if the tear gas being used has already expired,” Fauzi added.

So, what should people do if exposed to tear gas? Fauzi explained several immediate steps that can be taken:

• Move away from the source of exposure. Try to get to an open space and head in the opposite direction of the wind.
• Avoid rubbing your eyes or face. Tear gas causes eye redness, and rubbing will worsen the irritation.
• Rinse affected body parts with clean running water or saline solution (0.9% NaCl infusion fluid).
• Remove clothing that has been contaminated with tear gas particles.
• Control your breathing. If you experience respiratory discomfort, remain calm and breathe steadily. If available, use canned oxygen or an inhaler (especially for those with respiratory conditions).
• Seek medical help immediately if you experience severe shortness of breath.

Fauzi also advised people who plan to join demonstrations or happen to be around protest zones to prepare protective gear such as masks. In addition, laboratory safety goggles can help shield the eyes from tear gas exposure.

“But abroad, when tear gas is thrown, sometimes the crowd throws it back at the officers,” he joked.

Fauzi also reminded the public not to apply toothpaste on the face, as there is no scientific evidence that toothpaste can block the effects of tear gas.

The police often resort to tear gas to disperse or control crowds. One of the darkest tragedies linked to its use occurred during the football match between Arema and their rival Persebaya Surabaya at Kanjuruhan Stadium, Malang, East Java, on October 1, 2022.

The public remembers it as the Kanjuruhan Tragedy. At that time, police fired tear gas to disperse the spectators. Unfortunately, the ensuing panic drove hundreds of people to crowd into one of the exit gates.

As a result, a deadly stampede occurred, leaving 135 people dead in what became the worst football tragedy in Indonesia’s history.

Most recently, tear gas was used to push back students staging a demonstration in Bandung City on Monday (1/9/2025). Police fired tear gas that spread into the campuses of Universitas Islam Bandung and Universitas Pasundan. The incident injured dozens of students, medical workers, and security officers.

Writer: Gede Arga Adrian

Translator: Farizal Luqman Majid

Editor: Al Habiib Josy Asheva