Water chemistry maintenance is mission critical for any pool and spa professional. The water found in aquatic facilities must be inhospitable to pathogens and devoid of chemicals or particulate that can cause adverse health effects and/or turbidity in the water. These concerns are part of the daily tasks for the people who manage our pools and spas. It’s the job of the other stakeholders in the industry to make that job easier.

In 2011, public officials made a presentation to the NSF/ANSI Standard 50 Recreational Water Facility Joint Committee (RWFJC) about their concerns with materials and chemicals used in the pool and spa industry. The RWFJC is composed of three equal voting membership groups of 11 persons each representing the following sectors: public health (such as the CDC and state and county public health inspectors and administrators), product manufacturers (such as makers of pumps, filters, UV systems, etc.), and end users (such as facility designers, facility operators, trade association members, etc.).

The presentation by public officials centered on the seemingly uncontrolled use of non-certified chemicals in the pool and spa industry as well as concerns about water contact materials such as liners, coatings, covers or other pool and spa shell materials. Although a few pool and spa chemical types undergo some sort of third-party review, most are not evaluated for their use in pool and spa applications. The officials noted that it appeared that the use of some chemicals seemed to have no benefit at all or even had an adverse effect on water chemistry maintenance. Concerns were also raised because some materials leached colors or seemed to degrade and generate foam. The officials noted that they had no readily available mechanism to properly evaluate chemicals for leachate, efficacy, claim verification, percent active ingredient, degradation resistance, health safety and other aspects or potential risks.

Of the chemicals discussed, one in particular seemed to be a good example of how a chemical can be used to help or hinder pool water chemistry: cyanuric acid. CYA is used in outdoor pools and spas as a means of sequestering chlorine to slow down its degradation in the presence of sun. This effect has benefits as well as risks. When the chlorine is sequestered, it is still present, but not able to act with the same level of efficacy as it could if not sequestered. Of concern to public officials was the sequestering function of CYA on the oxidative and disinfection action of chlorine. The use of CYA can lead to miscalculations about how much free chlorine is actively available for disinfection and oxidation. Officials and manufacturers noted that CYA should never be dosed into indoor pools, spas or waterparks due to the lack of solar radiation-related degradation of hypochlorous acid.

During the 2012 RWFJC task group meetings, the group noted that the United States Environmental Protection Agency has a program that includes an initial paperwork review of submittals from manufacturers of a few chemical types. This program was seen as good in some aspects (detailed data submittal and label claim review), but as needing greater transparency and completeness (such as follow-up monitoring) in some areas and potentially less burdensome detail in other aspects. The NSF joint committee concluded that there was a need for a more comprehensive program for the evaluation of pool and spa chemicals. It was decided that there were certain aspects of the existing NSF/ANSI Standard 50 which were appropriate. Others supported certain drinking water evaluation criteria from NSF/ANSI Standard 60 and NSF/ANSI Standard 61 and felt they would be useful to incorporate for certain material types. All agreed that there was work to be done to find the right balance in the risk assessment for pool, spa and waterpark product efficacy; disinfection claims; performance verification; percent active ingredient, labeling, and packaging evaluation and testing; annual facility inspections; and monitoring test frequency and scope.

In early 2012, NSF held the first meeting of the NSF/ANSI Standard 50 task group on materials and chemicals. The group met several times in 2012 and invited staff from various public health agencies for discussion. Three programs were found to have some functional review process in place: New York Department of Health, California Department of Pesticide Regulation, and the EPA’s Office of Pesticide Programs, Anti microbials Division.

In order to understand their existing processes and infrastructure, NSF invited their participation in the task group. Staff from New York, Doug Sackett and Timothy Shay, gave an overview of their Bureau of Toxic Substance Assessment chemical evaluation program requirements.

Staff from California, Shelly Lopez and Brian Portoni, shared information about their scope of chemical and material evaluations related to pool, spa and waterpark applications as well as their risk assessment flow chart. The program not only included some health, safety and efficacy requirements for disinfectants, but also addressed adjuvants or chemicals which may support or help other chemicals be more effective.

Staff from the EPA’s Office of Pesticide Programs, Antimicrobials Division, Mark Hartman and Emily Mitchell, gave a detailed overview of the program for disinfectant chemicals and shared the EPA’s swim model for exposure and risk determination. NSF toxicology staff has reviewed this risk modeling approach and compared it with methods used in Europe as well as the NSF risk assessment programs related to drinking water.

The process of reviewing the assumptions and use characteristics is ongoing as NSF staff and the NSF/ANSI Standard 50 task group on chemicals and materials develop their recommendations for the different product categories such as:

• Water balance chemicals (buffers, acid, base, etc.)

• Clarifiers and filtration aids (coagulants, flocculants, etc.)

• Coatings, protective barrier materials, sealants and surfaces

• Disinfectants and sanitizers (chlorine, bromine, etc.)

• Oxidative additives (cleaners, degreasers, etc.)

Besides the obvious need for health and safety evaluation, other important aspects of the task group’s work includes development of methods to verify product acceptability, product content assurance, functionality, manufacturer claim compliance and performance quantification. To accomplish this goal, the task group will likely incorporate existing evaluation criteria and standards where appropriate.

For instance, some product types may already have viable testing methods which could be incorporated with virtually no modification. A structural material, surface barrier or anti-slip surfacing material might be evaluated in accordance with various NSF and ASTM standards for:

• Chemical extraction and health effects

• Slip resistance (if used in a flooring or step application)

• Hydrostatic loading

• Deflection

• Adhesion

• Impact resistance

• Abrasion resistance

Specific cycle times, substrates and a system of grading the performance values (such as level 1, level 2 and level 3 type performance) may yet need to be developed, but testing methods already exist.

Other types of evaluation which may be appropriate for various materials include:

• Color fastness (due to chemical exposure or UV exposure)

• Leachate of color or chemicals

• Chemical resistance (resistance to damage from common levels of chlorination)

• UV resistance and strength retention (if material for outdoor use and exposure)

For many of the assessment criteria, industry testing methods (from ASTM and NSF) already exists, which may be appropriate for incorporation into NSF/ANSI Standard 50. Further work on this topic will help flesh out the applicable criteria for various materials and chemicals.

If you are interested in participating in the NSF Standard 50 Recreational Water Facilities Joint Committee Task Group on Chemicals and Materials, send an email to Mindy Costello for more information.