Putting household water treatment products to the test

February 2016

WHO’s new International Scheme to Evaluate Household Water Treatment (HWT) Technologies ensures that products used to treat water in homes are effective in protecting health.

Girl holding a glass of water
WaterAid/Tom Greenwood

Globally, an estimated 1.9 billion people rely on water supplies that are contaminated with faeces. This requires many to use household water treatment (HWT) technologies to help prevent disease and make water safe for drinking.

The global market for HWT products has now become flooded with products. From chlorination to filtration systems and solar disinfection, the options for purifying water are endless. Manufacturers claim their products make water safe for drinking, but in low-income countries, where many of these devices are essential, labs lack the capacity to verify these claims.

But, times are changing.

“The primary benefit from household water treatment is protecting health,” says WHO's Dr Batsi Majuru.

Now, the health benefits of HWT are increasingly recognized and the need for independent and rigorous evaluation is essential, adds Dr Majuru.

It is estimated that when used correctly and consistently, HWT and safe storage of water can reduce diarrhoeal diseases by as much as 45%, and save thousands of young children every year.

An international evaluation scheme

The International Scheme to Evaluate Household Water Treatment Technologies was established in 2014 to independently and consistently assess the performance of HWT products against WHO health-based criteria - an evaluation system similar to how pharmaceuticals and insecticide-treated bed nets are pre-qualified.

Under the Scheme, a product can be evaluated if it is low-cost, appropriate for low-income settings, free standing and able to treat enough water to serve a limited number of individuals for a day. Products that meet these requirements are tested to see how well they remove microbiological contaminants, such as bacteria, viruses and protozoa, from drinking water. Product performance is classified based a 3 tiered system and those that achieve the highest removal of pathogens are given a 3-star rating.

“The primary benefit from household water treatment is protecting health.”

Dr Batsi Majuru, WHO technical officer, Department of Public Health, Social and Environmental Determinants of Health

Recently, WHO released the first round of results on 10 HWT technologies ranging from ultrafiltration to chemical disinfection and found 8 met performance targets. These products reach an estimated 60 countries and millions of users. Every year, WHO plans to test new technologies and release results to help countries like Ethiopia that are working to scale-up HWTselect the technologies that meet WHO performance criteria.

Improving regulation in Ethiopia

Ethiopia is often affected by droughts and floods, meaning that safe drinking water can be hard to come by and diarrhoeal diseases are common. To address the situation, the Government launched the ‘One WASH Programme’, which aims to achieve universal access to safe water, sanitation and hygiene, and improve safe storage and treatment practices in the household.

Prior to WHO’s scheme, many laboratories tried to evaluate HWT products, but there were no standard protocols or test processes. Now, the Ethiopian Food, Medicine and Health Care Administration Control Authority, which is mandated to test the safety of pharmaceuticals, food and beverages, is also mandated to regulate HWT products.

“Previously, we only conducted document reviews and chemical testing on chlorine-based HWT technologies being used in the country,” says Bikila Bayissa, Deputy Director General of Food & Medicines Quality Assessment, Ethiopian Food, Medicine and Health Care Administration & Control Authority. “Now, through WHO’s Scheme, we are also focusing on the microbiology, which is critical to ensuring drinking water is safe.”

WHO is working with the Government of Ethiopia to train staff from various government laboratories, ministries and regulatory bodies on how to do the microbiological testing to evaluate product performance, as well as implementing WHO Guidelines on Drinking-water Quality.

“Many HWT products are imported from other countries, but no one knows if they are good or bad,” says Dr Almaz Gonfa, coordinator, Food Microbiology and Food Safety Research Lab at Ethiopian Public Health Institute. “The WHO Scheme will help Ethiopians know the products they are using are actually cleaning their water and protecting their health.”

Scaling-up in more countries

Universal access to safe drinking water is called for in the Sustainable Development Goals. By strengthening protection and management of water supplies, including at the household level, WHO and governments are taking steps to achieve this goal.

This year, WHO is working with the Government of Ghana to develop HWT performance standards and a certification and product labelling system to aid users in making informed purchases. Once launched, the certification programme will support the Government’s National Strategy for Household Water Treatment and Safe Storage, aimed at reducing waterborne diseases by 2025.

“WHO’s scheme will help make sure the technologies in Ghana effectively clean water, are appropriate for local households and meet international standards,” says Kweku Quansah, programme officer, Ghanaian Ministry of Local Government & Rural Development.

“Once we pass technologies through the evaluation process, individuals will have the assurance that these technologies are internationally verified,” he adds.