What is Chlorine Gas Toxicity?
Chlorine gas is dangerous and classified as an irritant to the lungs. It dissolves somewhat in water and can cause severe damage to breathing passages. Chlorine gas is commonly used in industries, but it was also used as a harmful chemical weapon during World War I. These days, people commonly come into contact with chlorine gas due to accidents in industries or mishaps with household cleaning products. For example, there have been several cases of train accidents transporting liquid chlorine which caused the gas to leak into the environment. At home, mixing chlorine bleach with other household items that contain acid or ammonia can also lead to exposure to chlorine gas.
The harm caused by chlorine gas exposure depends on how much of it you’re exposed to and how long the exposure lasts. At low concentrations (1 to 3 parts per million), chlorine gas can irritate the eyes and the lining of your mouth; at 15 parts per million, you may start having trouble with your lungs, and exposure at 430 parts per million can be deadly within 30 minutes.
Chlorine gas has a strong smell making it easier to detect if there’s any leak. Symptoms after exposure may include the burning sensation in the eyes, throat, and lungs. If anyone’s exposed to a higher concentration, it can cause tightening of the airways, lower lung problems and delayed swelling in the lungs.
What Causes Chlorine Gas Toxicity?
Chlorine gas is often used to keep swimming pools clean or can be created accidentally by mixing certain household products. When bleach (known scientifically as sodium hypochlorite) is mixed with an acid, it creates chlorine gas. This gas is heavy, has a yellow-green color, and gives off a strong, distinct smell.
Aside from cleaning, chlorine gas has various other uses. It’s used in industries to help make a wide range of products – from bulk materials and bleached paper goods to certain kinds of plastics like PVC and different solvents. It’s also used in the creation of dyes, textiles, paint, and even some medications.
For storage purposes, chlorine gas is usually pressurized and cooled to turn it into a liquid form. When this liquid form is released, it quickly turns back into a gas that has a yellow-green color and pungent smell. Since chlorine is denser than air, it tends to gather in low areas.
Historically, chlorine gas has been used as a weapon during wars, with the most recent known use being in Iraq in 2007.
Risk Factors and Frequency for Chlorine Gas Toxicity
Chlorine is a common inhalational irritant, with over 6300 exposures reported by the American Association of Poison Control Centers in 2016. This makes it the most common cause of such irritation in the United States. A significant portion of these exposures – around 35% of them – are caused when household acid is inadvertently mixed with a compound called hypochlorite.
However, household exposure isn’t the only risk. There have been numerous incidents of chlorine gas being released accidently. For instance, in 2007, a serious accident occurred when a railroad tanker full of chlorine collided with another train. The accident triggered a rupture in the tank and a frightening 90 tons of chlorine gas were released. The accident caused nine deaths and resulted in 520 emergency department visits in Graniteville, South Carolina.
On an international level, chlorine gas is often involved in major accidental release incidents. It’s popular in industries, which makes the risk of accidental exposure quite high.
In addition to household and industrial accidents, chlorine gas has been used as a weapon of war. For example, it was used by Germany in World War I. Even in recent times, chlorine has been weaponized. In 2007, insurgents in Iraq had used chlorine tankers filled with explosives, causing a large number of civilian casualties.
Signs and Symptoms of Chlorine Gas Toxicity
Chlorine gas exposure can lead to several symptoms that may vary depending on the level and duration of exposure. When exposure is short-term and at low levels (below 5 parts per million), symptoms can include tearing up, irritation in the nose and throat, and excessive saliva production. However, if the exposure is acute but at high levels, symptoms can be more severe and can include difficulty breathing, intense coughing, nausea, vomiting, feeling light-headed, headaches, pain in the chest and stomach, and eye injuries, in addition to the symptoms related to low-level exposure. Continuous exposure to chlorine gas over a long period can cause chest pain, coughing, sore throat, and coughing up blood.
A physical examination can reveal several signs linked to chlorine gas exposure. In terms of respiratory signs, doctors may observe rapid breathing, skin or lips turning blue, wheezing, chest retractions during breathing, decreased breath sounds, crackling sounds in the lungs, flaring of the nostrils, noisy breathing, bleeding in the respiratory tract, and a runny nose. Non-respiratory signs can include rapid heart rate, tearing up, and excessive saliva production.
Testing for Chlorine Gas Toxicity
If you’re exposed to a harmful substance, your healthcare provider will usually use a device called a pulse oximeter to check your oxygen levels. In situations where a large number of people are exposed at once, these devices might be reserved for people showing severe symptoms.
If you’re showing serious symptoms right after exposure, your doctor might ask for you to have a chest x-ray done. This helps see whether your lower respiratory tract, which includes parts of your airway and your lungs, is affected.
For those experiencing severe body-wide symptoms such as vomiting, confusion, or acidosis (a high level of acid in your body fluids), your doctor might need to check your blood. They might test your serum electrolytes, BUN (an indicator of kidney function), and creatinine levels (another kidney function indicator), carry out arterial blood gas analysis (a test measuring the oxygen and carbon dioxide levels in your blood), and do an electrocardiography (a test checking for problems with your heart’s electrical activity).
Once your immediate medical needs are addressed, your doctor might decide to carry further tests to understand the extent of the injury. This could involve testing your lung function, using a ventilation-perfusion test (which checks how well air and blood are moving through your lungs), or doing a laryngoscopy/bronchoscopy (procedures using special tubes to view the air passages of your lungs).
Treatment Options for Chlorine Gas Toxicity
The treatment for chlorine gas exposure mainly involves managing the symptoms and making sure the person is safe. The most crucial first step is to quickly remove the affected individual from the area contaminated with chlorine gas. Medical professionals will then examine the individual’s airway, breathing, and circulation, and if needed, provide humidified oxygen to alleviate respiratory problems.
In severe cases, wherein the person is unable to breathe on their own, a medical procedure, known as endotracheal intubation, might be done to open the airways. If the lungs are filling up with fluid not caused by heart issues (non-cardiogenic pulmonary edema), medical professionals may apply positive pressure at the end of breath exhalation (PEEP), limit fluids, and use water-removing medications (diuretics). Tightening of the airways (bronchospasm) can be treated with medications like albuterol that helps widen them.
If chlorine gas has come into contact with the eyes, rinsing the eyes with lots of water or a saline solution is necessary. If the eyes continue to be irritated after flushing, medical professionals may check for a corneal abrasion (a scrape on the cornea).
In certain cases, a 4% sodium bicarbonate solution, administered as a fine mist through a nebulizer, might help in treating chlorine gas exposure. However, its use is limited and not commonly practiced as there isn’t much experience with this form of treatment. Moreover, the use of anti-inflammatory medicines (corticosteroids) and systemic nitrites has not been proven to have any significant benefit for this type of exposure.
What else can Chlorine Gas Toxicity be?
Usually, when someone has been exposed to chlorine gas, they or the first responders who come to help them will be able to provide a clear history of the incident. This is because chlorine gas has a unique smell that many people would recognize from swimming pools that are cleaned with chlorine. However, in rare cases, a person might be found struggling to breathe or not fully conscious after all the chlorine gas has dispersed and it’s unclear what happened. The symptoms of exposure to chlorine gas, such as drooling, excessive tear production, a runny nose, and difficulty breathing due to constriction of the airways, are also seen in a type of poisoning called cholinergic toxicity.
What to expect with Chlorine Gas Toxicity
Exposure to chlorine gas is usually not serious, and most people recover without permanent harm. The most common health issue seen in moderate to severe cases of exposure is fluid build-up in the lungs, also known as pulmonary edema. This tends to occur within 2 to 4 hours of exposure to a moderate level of chlorine (25 to 50 parts per million, or ppm), or within 30 to 60 minutes of exposure to a high level of chlorine (more than 50 ppm).
Issues with the lungs usually get better within a week to a month after contact with chlorine gas. It is worth noting that those who smoke or have asthma, may likely experience long-term breathing issues.
Studies on the long-term health impacts resulting from short-term exposure to chlorine are unclear. Some research shows a decrease in vital capacity (the maximum amount of air a person can expel from the lungs), diffusing capacity (the lungs’ ability to transfer oxygen and carbon dioxide between the air and the blood), and total lung capacity (the maximum amount of air the lungs can hold). However, other studies show no clear-cut pattern of lung function issues.
Possible Complications When Diagnosed with Chlorine Gas Toxicity
In severe instances, the delicate lining of the lungs can start to peel away within 3 to 5 days. This can result in a chemical-induced lung inflammation, complicated by additional bacterial invasions and infections. If you’re a smoker or already have lung issues such as asthma or chronic obstructive pulmonary disease, the chances for long-term issues like lung scarring significantly increase.
- Lining of the lungs peeling away in severe cases
- Chemical-induced lung inflammation
- Additional bacterial invasion and infection
- Increased risk of lung scarring for smokers and individuals with existing lung conditions
Preventing Chlorine Gas Toxicity
To protect people from exposure to chlorine gas, there are three main approaches. The first one aims to improve the safe transportation of large amounts of liquid chlorine, which is usually carried by trains. The second one involves the creation and strict following of guidelines for using chlorine in industries, which can prevent accidental exposure at workplaces. The third one stresses the importance of educating consumers about the dangers of mixing different cleaning chemicals.
Healthcare providers will have to educate individuals who have been exposed to chlorine gas in their homes. If people fail to understand the danger of mixing certain chemicals, they may expose themselves to chlorine gas repeatedly. Learning about these risks can help prevent such situations.
