The Silver Filter Company Ltd.
The Silver Filter is a type of ceramic water purifier enhanced with colloidal silver.
Silver Filters are silver enhanced ceramic ‘pot’ water filters for household drinking water treatment. This filter was first developed in 1981 by Dr. Fernando Mazariegos of the Central American Industrial Research Institute (ICAITI) in Guatemala and is now promoted by Potters for Peace (PFP), a USA based nonprofit organization. These filters are low-tech and low-cost water filters that eliminate approximately 99.88% of water-born disease agents at the flow rate of 1-3 L/h.
This product is mainly implemented by Potters for Peace but is distributed worldwide by organizations such as the International Federation of the Red Cross and Red Crescent, Doctors Without Borders, UNICEF, Plan International, Project Concern International, Oxfam and USAID.
Primary competitors of these silver-enhanced ceramic filters include Ekofil filter, Ceramic filter UTP, Arcifiltro, Ecofiltro, or ceramic candle filters such as Stefani filtro flex.
Goal 6: Clean water and sanitation
Individuals and households
This product is locally made and is mass-produced in local target regions, identified by Potters for Peace. The building materials of this product includes locally sourced clay and sawdust. These are then later mixed with water, pressed into the filter shape, and fired to gain a ceramic state. Finally, the flow rates are tested to ensure the product consistency and at last coated with silver nitrate solution.
Users can obtain Silver Filters at retail stores or from distributing organizations.
Description of the type of ceramic filter (pot, candle, or disk)
What primary material is used (ceramic, mud, clay etc.)?
Additional materials added to improve disinfection
Manufacturer-specified flow rate (L/hr)
Laboratory-evaluated log scale removal rate of bacteria
Laboratory-evaluated log scale removal rate of viruses
Laboratory-evaluated log scale removal rate of protozoa
Reduction levels of heavy metals and/or arsenic through this treatment system
Manufacturer-specified maximum level of inlet turbidity (NTU)
Range or value of outlet turbidity levels (NTU)
How often/when should maintenance be performed?
What is the total number of liters that is recommended can be filtered?
Is there safe water storage integrated into this product?
Silver Filters consist of a porous 10 L capacity ceramic filtering element that suspends in a 30-liter plastic or ceramic receptacle that stores and dispenses filtered water. The flow rate is 1.5-3.0 liters per hour when full.
There is no technical support provided and users are expected to maintain the product on their own by scrubbing ceramic filter element with a brush.
Replaceable components include the tap for dispensing water, safe storage containers, and ceramic filtering elements.
Until it breaks, approximately 2 years.
This filter was designed to removes bacteria, parasites, and turbidity. Manufacturers specify these filters are low-tech and low-cost and eliminate approximately 99.88% of water-born disease agents.
No known safety hazards are related to this product.
Screen mesh or cloth as a pre-filter
Donachy, B., 2011, Summaries of Reports and Studies of the Ceramic Water Purifier (CWP): A Colloidal Silver (CS) Impregnated Ceramic Water Filter. Retrieved Dec, 6, p.2014.
Hagan, J.M et al., 2009. Resource development international-Cambodia ceramic water filter handbook. EWB Australia. Phnom Penh Cambodia.
Van Halem, D., 2006, Ceramic silver impregnated pot filters for household drinking water treatment in developing countries.
Lantagne, D.S., 2001, Investigation of the Potters for Peace colloidal silver impregnated ceramic filter. Report, 1, p.79.
This filter does not comply with WHO for the reduction of viruses, therefore, are unlikely to achieve a performance classification higher than one-star.
Field evaluations by Care International and Social Fund for Development.
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