Exposure to Endocrine Disruptors via Materials in Contact with Drinking Water
DWI0809
May 1999

Executive Summary

Recently there has been much media and public concern about the potential health effects of so-called endocrine disruptors. Many commonly used industrial chemicals are now considered to be endocrine disruptors and it is probable some of these chemicals are used in the manufacture of materials for use in contact with drinking water. Although, it is generally believed that drinking water is not a significant route of human exposure to endocrine disruptors, it is prudent to investigate the potential of materials in contact with drinking water to leach endocrine disruptors into drinking water.

In order to select endocrine disruptors for this study the following steps were taken:

1. A literature study was undertaken to find compounds reported to show endocrine disrupting properties, this list is given in Appendix A.
2. Chemicals were then rejected from this list if:
• the evidence was considered clearly insufficient to show endocrine disruption;
• they were not considered to be in common use in materials used in contact with drinking water.

The final list of chemicals is given in Table 2.1. Four groups of compounds were identified, namely: phthalates; bisphenols; alkyl phenols; alkyl phenol ethoxylates and polyethoxylates. Manufacturers were contacted to find out whether their products contained any of these chemicals.

It became apparent that a variety of materials used in contact with drinking water contain chemicals that are currently suspected to be endocrine disruptors. Most of these materials were site-applied products.

In all cases, when the materials were tested in the laboratory, any detected levels of endocrine disruptors were found to decrease over time. However, in many cases, when trying to relatinge the laboratory leaching test results to worst-case concentrations in actual drinking water, it was difficult. What constituted a worst case, in terms of the surface area in contact with water, the contact time and whether any high initial leaching would be flushedrun to waste was not always clear.

The indications were that concentrations in practice, sometimes after initially high short-term leaching, concentrations would be very low and probably negligible. However, at least one product requires further, more detailed, consideration.

Field testing of epoxy resins showed that long-term leaching, again sometimes after relatively high short-term leaching, was very low, usually not detectable. It would appear from these results that chronic exposure to suspected endocrine disruptors from materials in contact with drinking water is unlikely to be significant. However, initial exposure from newly installed products may require consideration of whether flushing procedures need to be modified.

In addition, it may be appropriate to reconsider controls on the application of site-applied materials, such as the maximum area that may be treated, in a particular time frame, in relation to the volume of water in contact and residence times.

Copies of this report may be available as an Acrobat pdf download under the 'Find Completed Research' heading on the DWI website.