December 21, 1999
Re: Public Comments in Response to Reregistration Eligibility Decision, Pentachlorophenol, Case 2505
Dear Mr. Elkassabany:
Thank you for the opportunity to comment on the science chapter of the Reregistration Eligibility Document (RED) for the antimicrobial pesticide pentachlorophenol (PCP). These comments are submitted on behalf of Beyond Pesticides/National Coalition Against the Misuse of Pesticides (NCAMP).
We look forward to receiving the revised science chapter that addresses the micro-contaminants of PCP, namely hexachlorobenzene, dioxins and furans. All of these contaminants are found in commercial grade PCP. We assume that this addition to the science chapter will consider PCP and its contaminants as a unit, looking at the potential synergistic and additive toxicity of this complex mixture of toxins. We will provide the Environmental Protection Agency (EPA) with a more complete set of comments after we have been given the opportunity to examine this additional information. A RED for PCP should be issued only if data on PCP and its contaminants are complete and support reregistration under the standards of authorizing legislation and corresponding regulations.
Beyond Pesticides/NCAMP conducted a survey of over 3,000 utility companies; collecting data in order to complete the picture of PCP use in the U.S. The results of that survey show that the EPA has neglected to consider a number of utility company practices that represent additional sources of exposure to workers, the public and the environment. Data from the survey pertaining to these practices are provided with these comments.
Beyond Pesticides/NCAMP has published a report combining information from the utility survey with some examples of the cancer risk estimates from the preliminary science chapter. Please find a copy of Pole Pollution: New Utility Pole Chemical Risks Identified By EPA While Survey Shows Widespread Contamination attached to these comments. Pages 16-21 of the report is a table of hazards, risks and data gaps revealed in the environmental fate and human risk assessment sections of the science chapter.
These comments do not represent a comprehensive list of the problems - the excessive risks assigned to PCP exposure and/or data gaps - in the PCP science chapter that cause our concern. Any one of the problems that are addressed in these comments is sufficient to mandate a Final Determination and Notice of Intent to Cancel and Deny Application for Reregistration of Pesticide Products Containing PCP. In sum, Beyond Pesticides/NCAMP feels that the only conclusion that EPA can reach is that PCP, when used in accordance with widespread and commonly recognized practice, causes unreasonable adverse effects on human health and the environment.
I. Based on Both the Known Hazards of PCP and Identified Data Gaps the EPA Cannot Reach the Conclusion that PCP Will Not Pose Unreasonable Risks to Humans or the Environment
In announcing its January 2, 1987 Final Determination and Notice of Intent to Cancel and Deny Application for Reregistrations of Pesticide Products Containing PCP (including but not limited to its salts and esters) for Nonwood Uses, EPA said:
The Agency is concerned about the ubiquity of pentachloro-phenol, its persistence in the environment, its fetotoxic and teratogenic properties, its presence in human tissues, and its oncogenic risks from the presence of dioxins in the technical material.
By this statement the Agency made clear that it is aware of and concerned by the toxicity and ubiquity of PCP. It is time now for the EPA to take the next logical step and deny application for reregistration of all uses of pesticide products containing PCP.
The EPA should issue a RED only when it has complete information on the product and its ingredients. At page one of the Executive Summary of the science chapter the agency states "data gaps prevented the calculation of MOEs [margin of exposure] for the worker applying liquid formulation at pressure treatment plants - retort workers (helpers/switchman)." This is particularly significant in light of the following information also found on page one of the science chapter:
Based on the best
available data and default assumptions used in this RED chapter, the short-
and intermediate-term non-cancer dermal risk estimates for occupational
handlers exceed the risk level of concern after maximum risk mitigation
measures have been applied . . . for the following scenarios:
According to the science chapter, at page 12, the EPA granted the registrant's request to waive the data required to estimate dermal and inhalation exposure at indoor sites (formerly guideline numbers 233 and 234). Additionally, the data requirements addressing dermal and inhalation exposures at outdoor sites is still outstanding. This is particularly disturbing in light of the fact that at page 77 of the Science chapter it is stated that all of the existing inhalation studies of PCP are considered unacceptable for regulatory purposes. The Science chapter goes on to state at page 77 that: "[d]ue to the lack of acceptable data, it was determined that pentachlorophenol be placed in Toxicity Category I for inhalation toxicity." (emphasis added).
In addition, EPA requires estimates of post-application dermal and inhalation exposure to PCP to support guideline numbers 875.2300, 875.2400, and 875.2500. Page 12 of the Science chapter states that there is no data available for the following list of post-application exposure scenarios:
treatment facility retort maintenance (e.g., inspecting or performing
routine maintenance of the retort)
(emphasis in the original).
The EPA has placed PCP in Toxicity Category I for inhalation toxicity. The EPA, by its own admission, recognizes that occupational handlers face an unreasonable risk of poisoning from exposure to PCP. In light of the unreasonable health risks faced by these workers can EPA in good conscious assume that workers in and around pressure treatment plants, for which no data is available, face no unreasonable risk?
II. The EPA Must Base its RED on the Risks Faced by Those People that are Most Likely to Contact PCP
It is important that the EPA consider the risks faced by people that have no other presumed contact with PCP other than ubiquitous wooden utility poles and other treated wood products in their communities. This group includes the vast majority of U.S. citizens. But basing a decision to reregister a poison on this level of exposure is inappropriate. A legitimate risk assessment focuses primarily on the dangers associated with the exposure levels faced by people that are in contact with PCP every working day. Are people that suffer occupational exposure to PCP of lesser value than anyone else in EPA's analysis? The answer to that question can be inferred from the agency's risk level of concern, >10-4 for occupational exposure; compared to the agency's risk level of concern for non-occupational exposure, >10-6.
The EPA fails to address the occupational exposure faced by people whose jobs are to manufacture, or store, or transport, or dispose of PCP. Instead the PCP science chapter focuses almost exclusively on occupational exposure through wood treatment plants and handlers of treated wood products. The science chapter states at page two that:
[c]ancer risk estimates for thirteen (13) exposure scenarios exceed the Agency's level of concern. Cancer risk estimates for occupational handlers using typical application rates do not exceed the Agency's risk level of concern (> 10-4), using maximum protective measures . . . for only one scenario . . . (emphasis in original).
Consulting Table 6 on page 108 of the science chapter reveals cancer risks as high as 3.4x100 for applicators of grease formulation for groundline remediation of utility poles (using a brush). The sheer size of the cancer risk assigned to applicators of groundline remediation speaks volumes about the hazards associated with exposure to PCP.
The science chapter states at page 113 that EPA has no data for the applicators of liquid formulation at pressure treatment plants - helpers/switchmen. Given the extremely high risk of cancer associated with applicators of grease formulation of PCP on utility poles (3.4x100 as mentioned above) it would be inappropriate for EPA to assume that any occupational exposure scenarios for which it has no data are associated with an acceptable risk.
III. The Data Available to the EPA Addressing the Risks Associated with Residential Post-application Exposure is Inadequate and can only Lead to a Final Determination and Notice of Intent to Cancel and Deny Application for Reregistration of Pesticide Products Containing PCP
The science chapter at page 123 notes that the "Agency is concerned that there are potential exposure concerns relating to post-application exposure to individuals following pentachlorophenol applications in residential settings." The science chapter, at page 123, lists the following potential residential exposure pathways:
(1) homeowner incidental
ingestion and dermal contact with soil contaminated with Pentachlorophenol
(e.g., soil contaminated by PCP-treated utility poles) (child);
It is troubling to find, also at page 123 of the science chapter, that no chemical-specific post-application studies conforming to OPPTS Test Guidelines Series 875 guidelines are available.
The Science chapter at page 7 points out that residues of PCP "in drinking water (when considered along with exposure from food and residential uses) pose an unacceptable chronic risk to children." Consulting Table 10 at page 125 the following exposure scenarios pose unacceptable residential post-application cancer risks for children: contact with soil contaminated with PCP, with both maximum (2.2x10-4) and minimum (1.2x10-6) risks unacceptable; and, outdoor residential contact with industry pressure-treated wood products, with an unacceptable maximum risk of 6.4x10-6.
In light of stated EPA data gaps and the recognized danger that PCP poses to children EPA cannot allow the reregistration of PCP.
IV. The Science Chapter Fails to Address Non-Occupational Post Application Exposure to PCP Through Handling Recycled/Re-Used Treated Wood Poles
Beyond Pesticides/NCAMP's survey of utility companies found that 70% of respondents gave or sold their discarded chemically treated wood poles to the public. These poles are used by private citizens and local government agencies for fence material, parking lot boundaries and a variety of other projects. A remarkable example includes the presentation of an award by the Kansas Department of Health and Environment on September 29, 1999 to Western Resources for their program of recycling electric transmission poles. The list of completed power pole lumber projects in that case includes bridges, a handicapped-accessible wildlife observation platform, an environmental classroom shelter, and a bird viewing blind as well as numerous nest boxes. It is safe to assume that young children visit these structures and are exposed through inhalation and dermal contact to PCP.
The used utility poles have to be cut to size by homeowners for use on projects. The toxic saw dust ends up on the skin and in the lungs of these unfortunate people and their families. Children play on and around the finished projects.
The PCP science chapter neglects to examine this source of exposure. This is alarming given the EPA's own estimation of risks from residential exposure to PCP. In fact, EPA has prohibited most indoor applications and indoor uses of PCP treated wood. Unfortunately, the good people of Kansas are unaware of the dangers of exposure to PCP from the use of PCP treated lumbar. How many communities are recycling treated wood poles in similar ways?
Our analysis of the
science chapter of the RED for PCP reveals numerous examples of data gaps.
EPA has a responsibility to conduct a cradle to grave analysis of PCP,
and the other wood preservatives in turn. The main focus of the science
chapter is the risks of occupational exposure related to wood treatment
plants. This approach is clearly inadequate.
There is an absence of analysis on the health risks associated with post-application exposure to PCP from the use of discarded wood utility poles. A majority of utility companies give or sell their discarded poles to the public. This represents a very hazardous exposure scenario that the EPA must factor into its risk assessment.
We look forward to engaging EPA in a meaningful discussion on the issues outlined in these comments. The issues are of grave concern given the hazards associated with PCP and its contaminants, as well as the larger question of how EPA conducts its evaluations in the RED process.