What are trihalomethanes?

As with many things in life, chlorine use doesn’t come with risk. However, chlorine’s vast range of benefits largely outweigh any known risks – risks such as trihalomethanes.

The use of chlorine to ensure safe drinking water is one of the greatest public health achievements.

Since the beginning of the twentieth century, our drinking water has been safe for consumption thanks to the use of chlorine. In fact, diseases such as typhoid fever and cholera have been completely eradicated from the western world thanks to clean drinking water – an accomplishment which wouldn’t have been possible without chlorine usage.

Chlorine isn’t just used for our drinking water either. In the modern world, it’s used across a variety of industries and sectors, including leisure, food processing, agriculture and more.

As with many things in life, chlorine use doesn’t come with risk. However, chlorine’s vast range of benefits largely outweigh any known risks – risks such as trihalomethanes.

What are trihalomethanes?

Trihalomethanes (THMs) are chemical compounds which may be found in water treated by chlorine, including indoor swimming pools and outdoor splash parks.

THMs may be formed as a result of adding chlorine to water containing high levels of organic material, like vegetation. This usually occurs when source water originates from a raw source, such as a creek, river or stream.

In rare cases, long-term exposure to THMs has been suggested to have effects on human health. However, the benefits of using chlorine to treat our water are much greater than any possible health risk from THM exposure.

Humans can be exposed to trihalomethanes in different ways. Not only can THMs be ingested (swallowed) if present in water, but they can also be inhaled if present in air – this occurs when water evaporates.

Lastly, THMs can be absorbed through the skin while showering, bathing or swimming in a chlorinated pool.

How do THMs affect health?

Short-term health effects of THMs in drinking water are rare.  Therefore, temporary raised levels of THMs are unlikely to result in any risk to health.

However, some studies suggest a link between long term exposure to THMs (over many years) and cancer and reproductive effects, but the evidence is not conclusive. Because of this, THMs are classified as ‘possibly carcinogenic’ to humans (See HSE for more).

Any such possible risks are, however, are much lower than the risk of serious illness that could result from using water that has not been properly disinfected. Without proper water disinfection, the effects of bacteria such as legionella are far more detrimental to human health.

Testing water for THMs

The legal limit of total THMs in drinking water in Europe is 100 µg (microgrammes) per litre. The legal limit for total THMs is based on a level of exposure (through inhalation and ingestion) that is acceptable over a lifetime (70 years) and safety factors are built into the calculations. All public water supplies are tested for THMs, typically more frequently than other types of supplies.

The benefits of chlorine dioxide use

As mentioned, the benefits of water disinfection using chlorine massively outweigh the potential risks of THM consumption. That is why chlorine has been paramount in both primary and secondary water disinfection for over 100 years.

Our unique, patented chlorine generation systems offer a safe, reliable method for on-site chlorine generation. They showcase a wide range of valuable benefits which can be utilised by swimming pools, water treatment plants, food processing lines and more.

Not only do our chloriDOS® iOX® chlorine dioxide disinfection systems require minimal maintenance, they use unique, accurate blending technology that significantly reduces the chemicals required for effective chlorination – saving business expenditure in the long haul to create recurrent annual cost saving benefits.

Other benefits of using chloriDOS® iOX® as a water disinfection system is optimal safety. Chlorine dioxide generation on-site removes the hazard of spillages and leaks, putting staff and customer safety at the forefront of operations. In-situ chlorine generation also improves sustainability measures by reducing the environmental impact of transportation to site.

chloriDOS iOX system tackles THMs at South Queensland water treatment plant

WestWater (one of our trusted approved distribution partners), in partnership with a South Queensland Regional Council, started a 12-month trial utilising chlorine dioxide generation and dosing at a potable water treatment plant using our chloriDOS® iOX® technology. To find out more about the trail and results, read the full THMs case study.

Call us today 01254 350180 or contact Gaffey Technical Services to find out more about our chloriDOS iOX® chlorine dioxide generation systems.

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