The first NSF International standard designed specifically for swimming pool treatment chemicals is on the horizon.
The standard is in the final stages of balloting and will be included in the next edition of NSF/ANSI Standard 50: Equipment for Pools, Spas, Hot Tubs, and Other Recreational Water Facilities. The new document was drafted by a task group consisting of public health professionals, recreational water facility operators and treatment chemical manufacturers.
The new information will be added to the next edition of NSF/ANSI 50 as Annex A, Toxicology Review and Evaluation Procedures for Swimming Pool Treatment Chemicals, as summarized below. At this time, the inclusion of evaluation criteria for pool treatment chemicals in NSF/ANSI 50 is focused primarily in the area of health effects parameters. This is most important for chemicals that are not covered by the scope of the U.S. EPA Federal Insecticide, Fungicide, and Rodenticide Act requirements, such as algaecides and biocides, which undergo a separate evaluation/registration through the EPA Office of Pesticides. Disinfectants, algaecides and other biocides that are registered by EPA are not subject to the additional risk assessment criteria of this Annex.
NSF would like to thank all members of the NSF/ANSI 50 Recreational Water Facilities Joint Committee Task Group on Chemicals and Materials for sharing their time and expertise in the development of the pool treatment chemicals evaluation criteria. If you are interested in participating in this task group, please contact Lauren Panoff at [email protected] for more information.
Summary of Annex A (NSF/ANSI 50); Toxicology Review and Evaluation Procedures for Swimming Pool Treatment Chemicals:
a) Detailed product formulation information shall be obtained that allows for the identification of all unique chemical components of the product, as well as the concentrations of each component. Additionally, the maximum recommended dose rate of the product shall be provided.
b) Based on formulation information and label or use instructions, the concentration of each swimming pool treatment chemical (and/or contaminants) in the swimming pool water following dosing at the maximum recommended dose rate shall be calculated.
c) As an initial toxicity screening evaluation, any chemical constituent (or contaminant) in the product formulation that has a concentration in the swimming pool water of ≤10 µg/L at the maximum recommended dose does not require further toxicology evaluation. This threshold value shall not apply to any substance for which available toxicity data and sound scientific judgment indicate a significant increase for an adverse health effect at a swimming pool water concentration at or below 10 µg/L. All chemical constituents (or contaminants) that exceed the 10 µg/L threshold at or below the maximum recommended dose require additional evaluation.
d) For chemical constituents (or contaminants) with concentrations in the swimming pool water that exceed 10 µg/L at or below the maximum recommended dose, an exposure assessment shall be performed utilizing equations and assumptions described in Annex A, Section A.5.
e) Following the determination of exposure levels (in mg/kg-day) for chemical constituents (or contaminants) with concentrations in the swimming pool water that exceed 10 µg/L at or below the maximum recommended dose, the following approaches may be utilized to determine the acceptability of the calculated exposure:
• A determination shall be made as to whether a published (publicly available in printed or electronic format) and peer-reviewed quantitative risk assessment for the chronic exposure to the substance is available. When a quantitative risk assessment is available, the assessment and its corresponding reference dose shall be reviewed for their appropriateness in evaluating the human health risk of the swimming pool treatment chemical constituent (or contaminant).
• As an alternative approach, the total allowable concentration values as reported in NSF/ANSI 60 (2013) and NSF/ANSI 61 (2013) may be utilized if available for the specific chemical constituent (or contaminant) by converting the TAC value into a mg/kg-day rate by utilizing default body weight and drinking water consumption assumptions (70 kg and 2 L), respectively. The resulting mg/kg-day rate may be compared with the estimated exposure at the maximum recommended dose to determine acceptability.
• If a TAC value or other published risk assessment value is unavailable, a risk assessment for the specific chemical constituent (or contaminant) may be conducted in accordance with the procedures outlined in Annex A.6.4; however, in lieu of determining a TAC value, the identified point of departure may be utilized to conduct a margin of exposure analysis.
• If a TAC value or other published risk assessment value is unavailable and there are insufficient toxicity data from which to perform a risk assessment in accordance with Annex A.6.4, the chemical exposure cannot be assessed and presence of the chemical in the formulation is precluded at a concentration greater than 10 ug/L.
