Emergency do not consume/do not use concentrations for blended phosphates in drinking water
C C Willhite1, G L Ball, V S Bhat
1Risk Sciences International, Washington DC, USA. calvinwillhite@hotmail.com
Human & Experimental Toxicology
|October 13, 2012
Summary
Polyphosphates in drinking water can cause harm. Derived safe limits for consumption and contact are 600 mg PO(4)/L for ingestion and 50 mg PO(4)/L for ocular contact.
Area of Science:
- Environmental Science
- Toxicology
- Public Health
Background:
- U.S. Congress mandates vulnerability assessments for community water systems under the Safe Drinking Water Act.
- Blended phosphates (polyphosphates) are used in municipal drinking water treatment.
- High concentrations of phosphates can pose health risks.
Purpose of the Study:
- To evaluate phosphate concentrations for regulatory decision-making regarding water safety.
- To establish safe exposure limits for polyphosphates in drinking water.
Main Methods:
- Literature review and analysis of existing toxicological data.
- Dose-response assessment for oral and topical exposure routes.
- Determination of 'do not consume' and 'do not use' concentrations based on adverse effects.
Main Results:
- A 'do not consume' concentration of 600 mg PO(4)/L was derived based on adult responses to monophosphate ingestion (diarrhea).
- A 'do not use' concentration of 8,000 mg PO(4)/L was established for skin contact, based on mild irritation.
- An acute ocular contact limit of 50 mg PO(4)/L was determined, considering rabbit eye irritation studies.
Conclusions:
- Phosphate concentrations in drinking water require careful management to prevent adverse health effects.
- Established limits provide guidance for regulatory agencies to ensure water safety.
- Potential risks include chemical burns, hyperphosphatemia, and acute phosphate nephropathy.
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