Protecting Lives and Assets: Understanding Chlorine Gas Leaks in Industrial and Local Areas

In January 2025, inner corridor hiking trails at the Grand Canyon National Park closed for around a day. It wasn't because of dangerous wildlife or a landslide - no, this closure was due to a chlorine gas leak.

Chlorine gas is an extremely common chemical used in water treatment and industrial applications. While it's all around us, acute exposure can be deadly. In the case of the recent Grand Canyon leak, containers of chlorine gas are flown into the area via helicopter and used to purify the drinking water supply. A leak caused trails to be shut down until the "cloud" of gas could safely dissipate.

Source: Wikimedia Commons

We'll cover what you need to know about chlorine gas, potential risks due to local and industrial leaks, and protective measures you can take to keep yourself safe from chlorine gas inhalation. 

WATCH NOW: Grand Canyon trails reopen after chlorine leak closure

What is Chlorine Gas? 

Chlorine is a gas at room temperature. It has a strong scent that most people are familiar with from swimming pools as it is used as a disinfectant in liquid form. 

It is often converted to a liquid for storage and transportation. 

Chlorine can explode when it reacts to other chemicals, including ammonia or fuel gas, so it's important that it is handled and stored correctly. Inhalation of chlorine gas causes acute respiratory symptoms, affecting the upper airway and ultimately leading to harmful symptoms like the development of arterial blood gas.

Low Concentrations of Chlorine for Water Disinfection 

If Chlorine is so hazardous, why is it used so commonly? 

Chlorine is an extremely effective disinfectant for water. Though the water in a stream, lake, or reservoir might look "clean," it harbors microscopic killers like bacteria, viruses, human and animal waste particles, and other microorganisms. Chlorination has been used for over 100 years to make drinking water safe and prevent diseases like dysentery and cholera. 

The concentration levels of chlorine in drinking water supplies are closely regulated, and public water systems must be regularly tested to ensure that there are no harmful byproducts of the chlorine interacting with other chemicals. 

Similarly, chlorine in the pool won't cause toxic effects. Those with sensitive skin, however, might notice adverse effects like itchy or burning skin if they fail to rinse off the pool water after a swim. 

Source: CDC on Unsplash

Uses of Chlorine Gas

Liquid chlorine, chlorine gas, and chlorine tablets are all commonly used to purify water, as well as having other industrial applications. 

It's an attractive option for maintaining a safe water supply for a number of reasons:

• Relatively inexpensive

• Easy to transport

• Water soluble

• Lingering effects prevent regrowth of microorganisms 

• Low risk of side effects 

That said, chlorine (in any of its forms) needs to be used in closely controlled doses to ensure that it doesn't react with trace chemicals in the water to form harmful compounds called  trihalomethanes (THMs). These compounds can cause reproductive harm, cancer, or nervous system disorders, so Federal and State regulations mandate that water supplies are regularly tested for THMs. 

The Deadly Toxicity and Health Risks of Chlorine Gas

Since chlorine is a gas at room temperature, it has specific storage requirements. 

When chlorine gas is accidentally released, its rapid spread and potent toxicity can have immediate and long-term health effects:

• Immediate Effects: Acute chlorine gas poisoning usually occurs when someone breathes in high concentrations of chlorine gas - over 15 ppm (parts per million). This leads to immediate trouble breathing, coughing, chest tightness, and eye irritation and can cause irritation in the upper airway, or even result in issues like the reactive airways dysfunction syndrome. 

• Lung Injury and Respiratory Toxicity: Chlorine gas can cause extensive damage to the respiratory system. This requires immediate hospitalization, sometimes including respirator care and usually corticosteroids. 

• Long-Term Consequences: Even low-levels of accidental chlorine exposure can have long-term effects if the exposure is frequent enough. Chronic exposure can lead to persistent cough, sore throat, chest pain, and hemoptysis (coughing up blood) or cause issues like acute respiratory distress syndrome. 

Treatment for chlorine poisoning can be very effective, if begun quickly after exposure. It's crucial to know the signs of being exposed to chlorine gas and the steps you need to take, especially for industrial workers who might be exposed in the workplace. 

READ NOW: The Hidden Dangers of Toxic Chemicals: What You Need to Know

The Industrial and Local Impact of Chlorine Gas Leaks

Since chlorine gas is such a common substance in residential and industrial uses, chlorine toxicity can sometimes be overlooked. Just like with other harsh chemicals, however, accidents or neglect can have enormous consequences to industrial workers, first responders, and local populations. 

Source: Aiken Standard 

Recent Chlorine Gas Leaks 

Industrial and transportation accidents in the United States have led to several industrial exposure injuries:

• In 2005, a train derailment in Graniteville, North Carolina released 90 tons of chlorine gas into the area. This led to 8 immediate deaths from asphyxiation due to acute chlorine gas exposure, plus over 500 injuries. 

• Another rail incident in 2007 led to the closure of the Port of Tacoma when chlorine gas was not transferred correctly to storage containers, leading to 25 injuries and massive loss of shipping time. 

• In 2009, catastrophe was narrowly avoided when a runaway tanker car full of chlorine gas was stopped just in time before it crashed in a densely populated area in Las Vegas. Researchers estimated that tens of thousands of people could have died if the chlorine gas had been released in the crowded city area. 

Is Chlorine Gas Fatal?

The National Institute of Health reports that pulmonary edema is the most common cause of death, usually 2 to 4 hours after exposure. 

Survival depends partially on duration of exposure and the overall vulnerability of the person affected. Preexisting lung conditions or repeated exposure to chlorine gas makes it more likely that severe injury will be sustained, which could end up blocking the upper airways. 

Luckily, survival is likely if the exposure levels are low and medical attention is received in time. Fatality usually occurs if one is exposed to too high concentrations of chlorine gas. 

Household Exposure

Common causes of chlorine exposure include household accidents. Household bleach contains chlorine and is commonly used for cleaning and laundry whitening. When bleach is mixed with ammonia, it releases a poisonous gas. Exposure may cause serious symptoms, including:

• Fluid in the lungs

• Eye irritation

• Coughing (irritation in the upper airway)

• Nausea

• Wheezing 

• Chest pain

• Shortness of breath 

Because ammonia is present in many household cleaners, like glass cleaner, you should never mix household cleaners of any kind, especially chlorine bleach, as it can lead to a serious reaction of chlorine, generating low levels of chlorine gas in your house. 

Similarly, a swimming pool accident can occur if pool treatment chemicals aren't stored properly or are dumped. Most fire departments recommend storing pool chemicals in a separate, locked shed to reduce risk. 

If it's suspected that these components have been mixed in the home, everyone in the home should seek medical care immediately after exposure. 

Source:  Kelly Sikkema on Unsplash

MIRA Safety’s Commitment to Your Protection

A recent investigative report revealed that hazardous chemical accidents happen almost daily somewhere in the United States. 

As many of these accidents are tied to transporting toxic chemicals, they could happen anywhere. Even if you don't live near a refinery or industrial center, the nation's railroad network is extensive and widely used to move chemicals.

Source: MIRA Safety 

MIRA Safety is built around the idea that everyone deserves military-grade protection for the worst that could happen. Part of your essential CBRN  (chemical, biologic, radioactive, nuclear) survival kit is a full-face respirator.

Models like our CM-101 Full Face Respirator are versatile, so you're prepared for a wide variety of potential threats. While you can't predict what kind of disaster will strike, keeping a pure flow of breathable air is absolutely essential to surviving and helping others in a crisis. 

READ NOW: Why You Should Have a Gas Mask in Your EDC Backpack Loadout

Military Uses of Chlorine Gas 

Historically, chlorine gas (like sulfur mustard) has been used in warfare. During WWI, the gas was used at the Battle of Ypres, causing over 1,100 deaths. This kind of usage causes burns of the upper respiratory tract as the gas reacts with water in the airways, producing hydrochloric acid. This burns away tissue and can quickly cause death or permanent damage. 

Source: Wikimedia Commons

Chemical weapons were banned by the Geneva Protocol in 1925. Despite this, there have been instances of chemical warfare in the 100 years since the international law was made, including during the Iran-Iraq War in the 1980s. 

2007 Iraq Chlorine Gas Attack 

Iraqi insurgents attacked U.S. forces in Fallujah in 2007 with a series of truck bombs filled with chlorine gas, injuring American and Iraqi forces. Reports at the time pointed to several symptoms consistent with chlorine poisoning, which include increased airways reactivity, skin and eye irritation, and trouble breathing. 

Attacks like this one increased concerns that terrorists could use easily available materials like chlorine for weapons, taking advantage of the lung injury induced by chlorine gas to quickly overwhelm even better-equipped militaries. 

Detecting Chlorine Gas Leaks

You can identify chlorine by its distinctive smell, similar to bleach.  

Chlorine is heavier than air and tends to have a greenish-yellow color in its gaseous form, meaning that it can be seen as something of a "thick mist" hanging in the air. 

Upon industrial exposure, symptoms usually appear very quickly. Early symptoms present include:

• Watering eyes

• Trouble breathing

• Coughing 

Even low levels of exposure can cause damage, so it's crucial to immediately evacuate any area where you suspect that chlorine gas may be present. You should always seek medical attention as soon as you safely can following chlorine exposure, even if you feel fine. 

Treatment for Chlorine Gas Exposure

Treatment for people exposed to chlorine gas consists mainly of supportive care. 

This includes:

• Supplemental oxygen - people who are wheezing or otherwise struggling to breathe, or who have hypoxia, are usually given supplemental oxygen to help their lungs recover more quickly and maintain safe levels of blood oxygen.

• Inhalers  - medications like albuterol (a drug commonly used for asthma attacks) can be used to help ease breathing and open airways. 

• Intubation  - in extreme cases, a breathing tube may be inserted after acute exposure to chlorine gas to assist with breathing. 

Conclusion

Accidents like the recent Grand Canyon leak or the 2005 train crash in Graniteville, North Carolina show just how dangerous even commonplace chemicals can be. 

Industrial chemicals are a fact of living in a modern industrial society. Following safety guidelines can limit the chances of occupational exposure. Making sure that your workplace and first responders are fully equipped with high-grade, air purifying respirators can protect cleanup crews from acute chlorine exposure when cleaning up from a disaster. 

Equip your team with full-face respirators that purify the air with 10-year shelf life filters and a full range of vision.