Chlorine dioxide is a powerful chemical widely used in water treatment, disinfection, and even some industrial applications. But can it be harmful to humans? There’s a lot of conflicting information out there, so let’s break it down and separate fact from fiction.
What is Chlorine Dioxide?
Chlorine dioxide (ClO₂) is a yellow-green gas known for its strong oxidising properties. It has been used for decades to disinfect drinking water, sterilise medical equipment, and even remove mould. Unlike chlorine, which forms potentially harmful byproducts, chlorine dioxide breaks down into simple salts, making it a preferred choice in many applications.
However, just because it’s used in water purification doesn’t mean it’s completely harmless.
Is Chlorine Dioxide Safe for Humans?
The answer depends on how you’re exposed to it. Chlorine dioxide is safe in controlled amounts but can be harmful in high concentrations or improper use. Let’s look at different ways people may come into contact with it and the associated risks.
Drinking Water Disinfection
Regulatory agencies like the HSE (Health & Safety Executive) and COSHH (Control of Substances Hazardous to Health) allow small amounts of chlorine dioxide to disinfect drinking water. At low concentrations (under 0.8 mg/L), it effectively kills bacteria and viruses without significant health risks.
However, consuming high amounts of chlorine dioxide or its by-products can cause nausea, vomiting, diarrhoea, and irritation of the oesophagus and stomach.
Inhalation Risks
Chlorine dioxide in gas form can be extremely dangerous if inhaled. Short-term exposure to high concentrations may result in respiratory issues such as coughing, wheezing, and shortness of breath. It can also cause lung irritation, leading to discomfort and difficulty breathing. Additionally, individuals exposed to high levels may experience headaches, dizziness, and irritation of the nose and throat.
Even at lower concentrations, prolonged exposure poses serious health risks. Over time, it can cause chronic lung damage, which may lead to long-term respiratory complications. Therefore, it is essential to minimise exposure and take proper safety precautions when handling chlorine dioxide.
Skin Contact
Liquid chlorine dioxide solutions can cause irritation to the skin and eyes. Direct contact may lead to redness and a burning sensation, making the affected area uncomfortable. In higher concentrations, exposure can result in severe eye irritation, which may cause pain and temporary vision problems. Additionally, prolonged or intense contact with the chemical increases the risk of chemical burns, which can be serious and require medical attention.
To prevent these harmful effects, it is highly recommended to wear gloves and eye protection when handling chlorine dioxide in high concentrations. Taking these precautions can help reduce the risk of injury and ensure safe handling of the substance.
Use in Alternative Health Treatments
Some individuals falsely claim that chlorine dioxide is a “miracle cure” for conditions like COVID-19, cancer, and autism. However, the MHRA (Medicines and Healthcare products Regulatory Agency) warns against its use as a health supplement due to serious risks.
Ingesting high doses can cause severe dehydration, haemolysis (red blood cell damage), kidney failure, and, in extreme cases, death. Given these dangers, it is essential to avoid chlorine dioxide as a treatment and rely on proven medical therapies instead.
How to Protect Yourself from Chlorine Dioxide Exposure
If you work with or encounter chlorine dioxide, here are some essential safety tips:
Follow Recommended Guidelines
- Never consume chlorine dioxide outside of regulated drinking water standards.
Use Proper Protective Equipment
- If handling chlorine dioxide solutions, wear gloves, goggles, and a mask to prevent direct contact and inhalation.
Ensure Proper Ventilation
- In industrial or laboratory settings, always work in a well-ventilated area to prevent inhalation risks.
Recognise Exposure Symptoms
- If you experience breathing difficulties, severe nausea, or skin burns, seek medical attention immediately.
Final Verdict: Should You Worry About Chlorine Dioxide?
Chlorine dioxide is safe when used correctly, particularly in water treatment. However, improper use, high exposure, or consumption in unapproved ways can be dangerous.
If you’re ever unsure about its use, always follow official safety guidelines and avoid misinformation.
Gas Detectors to Detect Chlorine Dioxide
Rockall Safety have a range of gas detectors that can detect Chlorine Dioxide. These include:
