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WHO International Scheme to Evaluate Household Water Treatment Technologies
UNICEF International Network on Household Water Treatment and Safe Storage10-13 November 2014Vientiane, Lao
Basis for Scheme
• Household Water Treatment– Implementable, cost-effective approach to improved water quality– May play an important role in protecting public health where
existing water sources are untreated, not treated properly, or become contaminated during distribution or storage.
• Important interim solution for:
– ~ 780 million without access to improved drinking-water supplies (http://www.unicef.org/media/files/JMPreport2012.pdf).
– Billions without access to safe and reliable drinking-water
Requires optimal choice, consistent and correct use!!!
How to make an optimal choice?
Technologies:
Physical removal (filtration, adsorption, sedimentation)
Chemical (chlorine, iodine, silver)
Disinfection by heat (boiling, pasteurization)
Ultraviolet (UV) radiation
Solar disinfection
Combination
Emerging technologies
Options! Options! Options!
How to choose: basis for Scheme
• Locally relevant performance specifications needed for decision-making for selection of technologies or approaches – Information is not always available
• To realize health gains associated with HWT– HWT technologies must sufficiently reduce pathogens to result
in significant health gains– Technologies must reach and be consistently and correctly used
by the populations most at risk for waterborne disease.
• Until recently: No international specifications to evaluate performance claims of HWT product against a health-based performance benchmark existed.
WHO Recommendations (WHO, 2011)
• WHO established an international evaluation scheme for HWT to fill the need for rigorous health-based assessments of HWT technologies (December 2012)
• First document that sets forth global criteria to
evaluate microbiological performance of HWT
(June 2011)
• WHO Scheme to Evaluate Household Water
Treatment (HWT) Technologies
• “The Scheme”
WHO Recommendations and the Scheme
Objectives: • Promote and coordinate independent and consistent testing for the
evaluation of household water treatment products based on WHO criteria
• Support national governments building technical capacity of research and laboratory institutions; especially in applying WHO Guidelines on Drinking-water Quality.
Aim: • Guide WHO Member States and procuring UN agencies in the
selection of technologies and support national governments in evaluation related functions.
Why a WHO International Scheme?
• Many countries do not have the capacity to evaluate HWT based on WHO recommendations
• Ensures criteria are appropriately adopted
• Effective mechanism to build national capacity
• WHO, global authority on public health
• Precedence: WHO Pesticide Evaluation Scheme, WHO Evaluation of Rapid Malaria Diagnostic Tests
Scheme Scope Products included in the Scheme
Household water treatment technology (definition)Products used in households or similar settings to remove microbiological water contaminants that may pose health risks.
Priority for testing: • Low-cost• Appropriate for developing country settings • Generally “free standing” products • Serve a limited number of individuals each
day.
Scheme ComponentsLaboratory Testing
Evaluation based on laboratory testing• Based on harmonized test protocol • http://www.who.int/household_water/scheme/HarmonizedTestProtocol.pdf?ua=1
• Microbiological reduction/inactivation performance specifications (not chemical)
• Tiered approach: series of health-based performance targets
Subsidized testing – funding secured for Scheme• Subsidy subject to availability of funds• Criteria: size and capital resources of manufacturer;
origin/location of manufacturer; local need; cost/liter treated
Scheme ComponentsDesignated Testing Laboratories
Selection criteria:• Institution with formal WHO relations• Not-for-profit, ISO certified• Stable income of core activities• Strictly adhere to harmonized test protocols/plans• Agree to WHO ownership of test results• http://www.who.int/household_water/scheme/laboratories/en/
Currently designated: • NSF International (USA); KWR (Netherlands)• Aim to designate labs in different geographic regions
Scheme ComponentsIndependent Advisory Committee (IAC)
• Advisory body to WHO on the Evaluation Scheme.
• Experts with demonstrated commitment to advancing public health
• Goal: attain an adequate technical distribution of expertise in drinking water quality, microbiology, water treatment technology and/or regulation, geographical and gender balance.
• http://www.who.int/household_water/scheme/IAC/en/
Scheme ComponentsPerformance - Tiered approach
WHO HWT: Series of health-based performance targets which allows for incremental improvements
Highly protective: 10-6 DALY/person/yearProtective: 10-4 DALY/person/yearLimited protection: Meets “protective” for two
classes of pathogens
Based on Disability-Adjusted Life year (DALY)
Target pathogens: viruses, bacteria and protozoa
Rating Log10 reduction:
bacteriaLog10 reduction:
virusesLog10 reduction
protozoa
Highly protective(10-6 DALYs/ P/yr)
≥ 499.99%
≥ 599.999%
≥ 499.99%
Protective
(10-4 DALYs/ P/yr)
≥ 299%
≥ 399.9%
≥ 299%
Limited protection
Achieves “protective” target for two classes of pathogens
Basis for assessing performance
Scheme Procedure
Invitation for expression of interest• Manufacturers to submit detailed information on product
WHO screening of dossiers• WHO will review with input from the Independent Advisory
Committee and determine which products are eligible for testing
Testing (or evaluation of exiting data)• Products and payment for testing sent to laboratories• Specific test plans, based on harmonized test protocol,
developed by laboratories in consultation with manufacturers
Scheme Procedure, contin
Testing Results and Reporting• Laboratory will report results to WHO• WHO with advice from IAC will determine level of performance• Summary of ALL results posted on WHO website
Use of Information • Manufacturers can discretely list performance level achieved in
technical material addressed to water and health professionals• May not use WHO name or logo in any manner
Maintenance • Manufacturers update WHO on changes in product/manufacturing
Challenges and Conclusion
• Starting simple; 2 laboratories and technically advanced protocols
• Future work on simplifying protocols and building national laboratory capacity
• Linking evaluation to new and innovative products
• Optimizing performance in tandem with achieving consistent and correct use
HWT only has health impact if used consistently and correctly by at-risk populations!
WHO/ M Montgomery
More information
Visit Scheme Webpage: http://who.int/entity/household_water/scheme/en/
Contact: Nikki Beetsch
Water, Sanitation, Hygiene and Health
World Health Organization
