Reviewed by
Gavin Owen
Managing Director, ChloroKlean
Is Chlorine Dioxide Dangerous?
Chlorine dioxide gas at high concentrations can be hazardous if inhaled or improperly handled. However, it is important to distinguish between concentrated chlorine dioxide gas and the stabilised liquid products used in professional water treatment. These are fundamentally different in terms of risk.
ChloroKlean products are stabilised liquid formulations, not compressed gas. They do not require on-site gas generators, pressurised cylinders, or complex mixing equipment. When diluted in water according to the product label, the chlorine dioxide is released in-situ at very low concentrations - typically below 0.5 parts per million (ppm) in the treated water. Because the product is dosed into water rather than released as airborne gas, operator exposure is fundamentally different from industrial gas handling scenarios.
For context, chlorine dioxide has been used safely in UK and European drinking water treatment for decades. Major water utilities across the world rely on it as a primary disinfectant precisely because it is effective at such low concentrations. The World Health Organization includes chlorine dioxide in its Guidelines for Drinking-water Quality as an accepted disinfection method.
Every ChloroKlean product has been formulated against the safety assessment criteria of the BPR (Biocidal Products Regulation) framework. This assessment covers three areas: human health safety (risks to operators, occupants, and bystanders), environmental impact (aquatic toxicity, biodegradability, bioaccumulation), and efficacy (proven performance against target organisms). Products that do not meet all three criteria cannot be placed on the market.
Stabilised Liquid
ChloroKlean is supplied as a ready-to-use liquid. No gas generation equipment, no pressurised storage, and no complex dosing calculations. The product activates safely when diluted in water.
BPR Safety Assessed
Human health and environmental risk assessment is a mandatory part of active-substance evaluation and product authorisation under GB BPR (retained from EU Regulation 528/2012). This includes toxicological evaluation and exposure modelling for operators and bystanders.
Low Working Concentration
Effective disinfection at below 0.5 ppm in the treated water - a fraction of the concentrations used with traditional chlorine. Lower chemical usage means reduced operator handling and lower residual levels in the system.
"The safety concerns people read about online typically relate to concentrated chlorine dioxide gas used in industrial chemical manufacturing - a completely different scenario from water treatment. Our stabilised liquid products are specifically formulated for safe professional use. They activate gently in water at very low concentrations, with no gas generation equipment needed. That is why chlorine dioxide is trusted by water utilities and hospitals across the UK."
Gavin Owen, Managing Director, ChloroKlean
Personal Protective Equipment (PPE)
When handling concentrate ChloroKlean products, appropriate PPE should be worn to minimise exposure risks. The specific requirements depend on the product concentration and application method.
Eye Protection
Safety goggles or face shield when handling concentrates
Hand Protection
Chemical-resistant gloves (nitrile or neoprene)
Body Protection
Protective clothing, lab coat, or coveralls
Respiratory
Adequate ventilation; RPE if vapour present
Storage Requirements
Proper storage is essential for maintaining product efficacy and preventing hazards. Follow these guidelines for all ChloroKlean products:
- Store in original, tightly closed containers
- Keep in a cool, dry, well-ventilated area (below 25°C recommended)
- Protect from direct sunlight and heat sources
- Store away from acids, reducing agents, and combustible materials
- Keep containers upright to prevent leakage
- Ensure storage area has spill containment measures
- Do not store near food, animal feed, or drinking water supplies
Consult the product Safety Data Sheet (SDS) for specific storage requirements and shelf life information for each ChloroKlean product.
Handling Best Practices
Do
- Read the product label and SDS before use
- Ensure adequate ventilation during dosing
- Use calibrated dosing equipment
- Wash hands thoroughly after handling
- Keep emergency eyewash and shower accessible
- Follow recommended dosing rates
Do Not
- Mix with acids or other chemicals unless directed
- Use in enclosed spaces without ventilation
- Transfer to unlabelled containers
- Eat, drink, or smoke when handling
- Return unused product to original container
- Dispose of via drains without authorisation
First Aid Measures
Eye Contact
Rinse immediately with plenty of water for at least 15 minutes, holding eyelids open. Remove contact lenses if present and easy to do. Seek medical attention if irritation persists.
Skin Contact
Remove contaminated clothing. Wash affected skin with plenty of water and soap for at least 15 minutes. Seek medical attention if skin irritation develops or persists.
Inhalation
Move to fresh air immediately. If breathing is difficult, administer oxygen if trained to do so. If not breathing, perform artificial respiration. Seek medical attention.
Ingestion
Do not induce vomiting. Rinse mouth with water. Give water to drink if conscious. Seek immediate medical attention. Bring product label or SDS to medical personnel.
Is ChloroKlean Safe to Use?
When used according to the product label and Safety Data Sheet, ChloroKlean products are safe for their intended professional applications. ChloroKlean products are extensively tested to European standards to verify both efficacy and safety for their intended use cases.
EN Testing Completed
ChloroKlean products have undergone independent laboratory testing to demonstrate efficacy against target organisms. These tests are conducted by UKAS-accredited laboratories to recognised European standards.
BS EN 13623:2020 - Legionella Efficacy
ChloroKlean Plus has been independently tested to BS EN 13623:2020, the European standard for evaluating bactericidal activity against Legionella in aqueous systems. Testing confirmed:
- >4 log reduction against Legionella pneumophila NCTC 11192
- Effective at concentrations as low as 50 ppm
- 60-minute contact time at 30°C
- UKAS-accredited laboratory testing
EN 13623:2020 - Pseudomonas Efficacy
ChloroKlean products have been tested to EN 13623:2020 for bactericidal activity against Pseudomonas aeruginosa, a key waterborne pathogen in cooling systems and healthcare settings.
- Proven efficacy against Pseudomonas aeruginosa
- Tested to European standard EN 13623:2020
UBA Drinking Water Guidance Compliance
ChloroKlean products have demonstrated efficacy in accordance with the German Environment Agency (UBA) Drinking Water Guidance requirements for disinfection products.
- Effective against Escherichia coli (E. coli)
- Effective against Enterococcus faecium
- Effective against Bacteriophage MS2
- Effective against Bacteriophage PRD1
EN testing supports BPR product authorisation claims and provides evidence of efficacy for HSE compliance under HSG274 and ACOP L8 guidance. Additional EN testing data is available upon request.
Important Safety Notice
This page provides general safety guidance. Always refer to the specific product Safety Data Sheet (SDS) and product label for complete safety information. SDSs contain detailed hazard information, exposure limits, and emergency procedures specific to each ChloroKlean product.
Use biocides safely. Always read the label and product information before use.
Related Information
What is ChloroKlean?
Learn about ChloroKlean products, how they work, and their applications.
Read the guide