Safe and clean drinking water is a fundamental necessity for public health.

Conventional water disinfection methods, particularly chlorination, have been found to introduce harmful chemical by-products known as trihalomethanes (THMs).

A systematic review and meta-analysis published in Environmental Health Perspectives (2025) has highlighted the alarming association between exposure to THMs in drinking water and an increased risk of bladder and colorectal cancer, even at levels currently considered safe by US and EU regulations.

At Scotmas, we are pioneering innovative Chlorine Dioxide technology that ensures effective water disinfection without the formation of harmful THMs, providing a safer alternative for communities worldwide.

The Carcinogenic Risks of Trihalomethanes

THMs are disinfection by-products formed when chlorine reacts with natural organic matter in water. The four most common THMs, chloroform, bromoform, bromodichloromethane, and chlorodibromomethane, have been identified as genotoxic and carcinogenic in animal studies.

The systematic review by Helte et al. (2025) analysed epidemiologic evidence from 29 studies and found a statistically significant increase in bladder and colorectal cancer risk among populations exposed to higher THM concentrations.

1. Bladder Cancer: Individuals exposed to high levels of THMs had a relative risk (RR) increase of 1.33 (95% CI: 1.04–1.71), with significant risks appearing at concentrations as low as 41 µg/L.
2. Colorectal Cancer: A more modest but still concerning RR increase of 1.15 (95% CI: 1.07–1.24) was found, suggesting that THM exposure may contribute to colorectal cancer development over prolonged periods.

Notably, these increased cancer risks were observed at THM levels below current regulatory limits in the US (80 µg/L) and the EU (100 µg/L), suggesting that existing standards fail to protect against long-term health risks adequately.

Chlorine Dioxide: A Proven Alternative to THM-Forming Disinfection

At Scotmas, we provide a superior alternative to traditional chlorination – Chlorine Ddioxide (ClO₂). Unlike chlorine, Chlorine Dioxide disinfects water effectively without reacting with organic material to form THMs. Here’s why Chlorine Dioxide stands as the best solution for safe and sustainable water disinfection:

1. No Harmful By-Products
   1. Chlorine Dioxide selectively targets and eliminates bacteria, viruses, and biofilms without producing THMs or other toxic by-products.
   2. It prevents the formation of haloacetic acids (HAAs), another category of potentially harmful disinfection by-products.
2. Effective Across a Broad pH Range
   1. Traditional chlorine disinfection loses effectiveness at higher pH levels and forms more THMs in alkaline water conditions.
   2. Chlorine Dioxide remains highly effective across a wide pH range, ensuring consistent disinfection performance.
3. Sustained Residual Protection
   1. While chlorine rapidly dissipates, Chlorine Dioxide remains stable in the distribution system, offering prolonged protection against microbial contamination.
   2. This reduces the need for high dosing and prevents fluctuations in water quality.

Regulatory Adoption and Global Applications

As awareness grows about the risks associated with THMs, regulatory agencies and municipalities worldwide are turning to Chlorine Dioxide as a safer alternative. Scotmas’ Chlorine Dioxide solutions are widely used in:

1. Municipal Water Treatment: Protecting communities from THM-related health risks while ensuring effective pathogen control.
2. Healthcare and Industrial Water Systems: Reducing the risk of Legionella and other waterborne diseases.
3. Food and Beverage Processing: Providing superior sanitation without residual toxicity or off-flavours.
4. Agricultural and Livestock Water Supplies: Ensuring safe drinking water for animals and irrigation without the dangers of THM exposure.

The Safer Future with Scotmas

The latest scientific evidence underscores the urgent need to transition away from chlorine-based disinfection methods that produce THMs and increase cancer risks.

Scotmas’ Chlorine Dioxide technology completely removes this threat, offering a scientifically backed, environmentally friendly, and highly effective alternative for drinking water treatment. With a commitment to innovation and public health, Scotmas continues to develop solutions that protect people, industries, and ecosystems from harmful waterborne contaminants.

Contact us today to learn how Chlorine Dioxide can transform your water treatment process and safeguard health.