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inorganic arsenicals Notice of Final Determination 11/93

Inorganic Arsenicals; Conclusion of Special Review 



AGENCY: Environmental Protection Agency (EPA). 



ACTION: Notice of Final Determination; Conclusion of Special 

Review.  

.

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SUMMARY: This Notice announces the conclusion of the Special 

Review for the remaining non-wood preservative uses of the inorganic 

arsenicals. In 1988, a Notice of Final Determination for most 

of the non-wood uses was issued. In that Notice, EPA determined 

to cancel several registrations for inorganic arsenicals, leave 

two registrations in effect, and defer action on five remaining 

uses. Four of the remaining five uses subsequently were canceled. 

In 1991, the Agency proposed cancellation of the remaining use 

- arsenic acid on cotton. Subsequently, these registrations 

also were voluntarily canceled. Since there are no longer any 

viable registrations for these five uses, EPA is concluding 

the Special Review. 



FOR FURTHER INFORMATION CONTACT: Ann Sibold, Special Review 

and Reregistration Division (7508W), Environmental Protection 

Agency, 401 M St., SW., Washington, DC 20460. Office location 

and telephone number: Special Review Branch, 3rd floor, Crystal 

Station Building #1, 2800 Crystal Drive, Arlington, VA. 22202. 

(703) 308-8033. 



SUPPLEMENTARY INFORMATION:  



I. Introduction  



   This Notice concludes the Special Review of the five remaining 

non-wood preservative uses of the inorganic arsenicals. The 

Special Review of the inorganic arsenicals began on October 

18, 1978, when EPA issued a Notice of Rebuttable Presumption 

Against Registration (RPAR, now called a Special Review) (43 

FR 48267) for the wood preservative and non-wood preservative 

uses of inorganic arsenicals. The RPAR was triggered by the 

finding that use of the inorganic arsenicals met or exceeded 

the risk criteria for carcinogenicity, teratogenicity (developmental 

effects) and mutagenicity (genetic effects).  

   1. Wood preservative uses. In 1981 (46 FR 13020), EPA proposed 

changes to the terms and conditions of registration for the 

wood preservative uses of inorganic arsenicals. These changes 

were based on an assessment of the risks and benefits of continued 

registration of inorganic arsenicals as wood preservatives. 

The Final Determination, issued July 13, 1984, (49 FR 28666), 

required certain modifications to the terms and conditions of 

registration and concluded the Special Review for the wood preservative 

uses of the inorganic arsenicals. Subsequently, EPA received 

requests for hearings from registrants contesting the requirements 

of that Notice. EPA considered registrants' suggestions for 

reaching the goals of the July 13, 1984 Notice, and amended 

the Notice of Intent to Cancel (51 FR 1334, January 10, 1986). 

All registrants have either modified their registrations in 

accordance with the Amended Notice or their registrations were 

canceled.  

   2. Non-wood preservative uses. On January 2, 1987, EPA issued 

a Preliminary Determination proposing to cancel the registrations 

of virtually all of the non-wood preservative uses (the ``minor'' 

uses) of inorganic arsenicals (52 FR 132). This action was based 

on two risk concerns, acute toxicity and carcinogenicity. Acute 

toxicity had been added as a risk concern after the Special 

Review was initiated. It was based on a large number of accidental 

poisonings, particularly of children. The Agency found that 

the acute risks to children from accidental ingestion of arsenic 

compounds outweighed the benefits. Carcinogenicity was found 

to be a risk to workers handling inorganic arsenical pesticides. 

The Agency found that protective clothing or a restricted use 

classification would not reduce the risks to an acceptable level 

in light of the limited benefits. EPA deferred consideration 

of four inorganic arsenicals - the ``major'' uses, including 

arsenic acid on cotton and okra, sodium arsenite on grapes, 

calcium arsenate on turf, and lead arsenate on citrus-for the 

following reasons. First, these uses did not pose acute risks, 

and second, the Agency found it necessary to review further 

the potential risk from dermal and dietary exposure. In 1988, 

EPA issued a Final Determination to Cancel products containing 

inorganic arsenicals for most of the minor uses of inorganic 

arsenic (53 FR 24767). In this Notice, only two registrations 

were retained: the insecticidal use of arsenic trioxide in a 

sealed metal container and the solid formulation of arsenic 

trioxide used to control moles and gophers. These uses were 

retained because the products were packaged in a manner that 

reduced chances of exposure, so that the benefits of continued 

use outweighed risks. Finally, this Notice concluded the Special 

Review of the non-wood preservative uses except for the deferred 

uses. After a hearing requested by several registrants, an Administrative 

Law Judge upheld the cancellations, and in July, 1989, that 

determination was upheld by the Administrator.  

   The Agency subsequently took regulatory actions on the deferred 

uses of the inorganic arsenicals as discussed below.  

   On October 19, 1990, EPA announced receipt of a request to 

voluntarily cancel a registration of lead arsenate used as a 

growth regulator on citrus (55 FR 42445). EPA stated the cancellation 

would become effective December 18, 1990 unless EPA received 

a request to withdraw the cancellation during the comment period. 

No such request was received. The cancellation became effective 

January 22, 1991. The Registrant could sell existing stocks 

until October 19, 1991. Existing stocks in the hands of dealers 

and users could be sold and used until exhausted. Tolerances 

were revoked April 3, 1991 (56 FR 13593). The revocation took 

effect before the end of the last sales date set in the cancellation 

order because the Agency believed that all but untreated commodities 

had cleared the channels-of-trade by the end of 1990.  

   In a letter dated March 15, 1989, EPA canceled a registration 

of calcium arsenate on turf at the registrant's request. The 

registrant was permitted to sell existing stocks until February 

28, 1990. Existing stocks in the hands of dealers and end users 

could be sold and used until December 31, 1991.  

   On June 19, 1991, EPA announced that it had received a request 

for voluntary cancellation of the registration of sodium arsenite, 

a fungicide, on grapes (56 FR 28154). EPA also established a 

comment period to allow any interested party to have the registrations 

transferred. No requests for transfer were received. Thus, on 

January 13, 1992, EPA canceled the registrations (57 FR 1262). 

The registrant was allowed to sell and distribute existing stocks 

until January 13, 1993. All others were allowed to sell and 

use existing stock until supplies were exhausted. The tolerance 

was proposed for revocation in 1992 (57 FR 1244), and became 

final on July 22, 1993 (58 FR 39153). The effective date of 

the revocation is June 30, 1994.  

   Arsenic acid was also registered as a desiccant on okra grown 

for seed under the authority of section 24(c) of FIFRA. In 1989, 

the registrant requested voluntary cancellation from the state. 

The state allowed sale and use of existing stocks until November 

1990.  

   In 1991, EPA announced its preliminary determination to cancel 

the registration of arsenic acid as a desiccant on cotton (56 

FR 50576). The risk case was based on unacceptable cancer risks 

to workers exposed to arsenic, which is classified as a known 

human (Group A) carcinogen. The Agency concluded that these 

risks were not amenable to mitigation and were not balanced 

by the benefits to growers. In addition, while not a basis for 

initiating the Special Review, the Agency considered groundwater 

contamination a potential source of exposure. EPA further concluded 

that there were no practical protective measures to adequately 

mitigate exposure. Other matters addressed by EPA included: 

   (1) A proposal to prohibit the sale and use of existing stocks 

because the benefits associated with allowing time to sell and 

use existing stocks were judged to be limited and not justified 

when weighed against risks.  

   (2) A proposal to conclude the Special Review of all other 

non-wood preservative pesticide products containing inorganic 

arsenicals.  

   (3) A comment period which was later extended to June 5, 

1992, at the request of several commenters (57 FR 3755, dated 

January 31, 1992).  

   EPA transmitted copies of the PD 2/3 to the Secretary of 

Agriculture and the Scientific Advisory Panel (SAP) for comment. 

The SAP met on June 25, 1992, to review the scientific issues 

in the PD 2/3. The SAP and the Department of Agriculture's comments 

are summarized in this Notice. In addition, they are printed 

in full in the Support Document for the Conclusion of the Special 

Review together with EPA's response. This Support Document may 

be found in the public docket as described in Unit VI of this 

notice.  

   After the comment period closed, the registrants Elf Atochem 

North American (Atochem) and Voluntary Purchasing Groups (VPG) 

initiated discussions with the Agency regarding voluntary cancellation 

conditioned upon provision for sale and use of existing stocks 

through the 1993 use season. On May 6, 1993, (58 FR 26975), 

EPA announced receipt of voluntary requests from these registrants 

of arsenic acid to cancel their registrations of arsenic acid 

use on cotton. The cancellations were made effective immediately. 

In the cancellation order, EPA permitted existing stocks to 

be sold until October 31, 1993. Growers are permitted to use 

existing stocks until December 31, 1993. Registrants will buy 

back stocks (in unopened containers) remaining after the 1993 

use season. A discussion of the reasons for the change in the 

provision for sale and use of existing stocks may be found in 

Unit IV of this notice.  

   Subsequently, EPA found that Drexel Chemical Company also 

had a viable (although suspended) registration for arsenic acid 

cotton desiccant. After being contacted by EPA regarding this 

registration, Drexel requested voluntary cancellation, and notice 

of this action and the cancellation order was published in the 

Federal Register on July 22, 1993, (58 FR 39205).  

   The tolerance for arsenic acid on cottonseed was proposed 

for revocation on September 22, 1993 (58 FR 49267). With these 

actions, EPA completed review of the last inorganic arsenical 

in Special Review.  

   3. Conclusion of Special Review (PD4). In the PD 2/3 for 

arsenic acid on cotton (56 FR 50576), EPA set forth its risk/benefit 

determination for this use. After reviewing the comments received 

in response to the PD 2/3, EPA found no new information that 

would cause a change in the risk/benefit determination for arsenic 

acid on cotton. EPA's review of the comments, reconsideration 

of the risks and benefits of the registrants' proposal to permit 

the sale and use of existing stocks, and final determination 

regarding Special Review of arsenic acid on cotton are set forth 

in this document.  

   In addition, the PD 2/3 also proposed that the special review 

be concluded for lead arsenate on citrus, calcium arsenate on 

turf, sodium arsenite on grapes, and arsenic acid on okra grown 

for seed. The Agency's final determination regarding Special 

Review of these uses is set forth in this document.  



II. Summary of Risk Determinations and Agency Evaluation of 

Comments and Additional Data  





A. Hazard Characterization  



   In the PD 2/3 for arsenic acid (56 FR 50576), EPA discussed 

in detail the data on the carcinogenicity of arsenic. Arsenic 

is a known human (Group A) carcinogen, for which a dose-response 

relationship has been calculated for the inhalation and oral/dermal 

routes of exposure. The SAP reviewed and agreed with the risk 

characterization of the PD 2/3. Their comments are included 

in full in the Support Document. EPA received no other comments 

on the hazard characterization of arsenic. Thus, EPA has not 

revised the hazard characterization set forth in the PD2/3. 



B. Exposure and Risk Assessment  



   In the PD 2/3, the Agency discussed the basis for its estimates 

of the levels of inhalation and dermal exposure for workers 

handling arsenic acid. The PD 2/3 displays in tabular form the 

Agency's conclusions regarding levels of exposure and risk for 

different occupations and different geographical regions where 

arsenic acid is applied. Estimates of excess upper bound risks 

ranged from 10.-2 to 10.-7. In addition, the Agency calculated 

levels of potential exposure and risk for residents living in 

the vicinity of cotton gins. The estimated excess upper bound 

risk was estimated at 10.-3. EPA also found that there was a 

potential for arsenic to contaminate groundwater. The SAP reviewed 

and agreed with the risk characterization of the PD 2/3. The 

USDA comments did not specifically address the exposure and 

risk assessment of the PD 2/3. The Agency received several other 

public comments on its exposure case. These comments questioned 

exposure measurements for closed cabs, mixer/loader exposure, 

pilot exposure, ground-water concerns, the definition of a ``normal'' 

work year for harvesters, the use of the Pesticide Handlers 

Exposure Database (PHED), estimates of risk to area residents, 

and regulatory jurisdiction over cotton gin workers. Commenters 

submitted some new data relating to enclosed cab exposure, but 

noted that the limited data could not support a regulatory decision. 

   EPA carefully considered these comments. However, neither 

the comments nor the new data received could demonstrate that 

EPA's exposure estimates should be revised. Thus, EPA has not 

changed its exposure estimates or its risk case. A detailed 

discussion of the comments and the Agency response are available 

in the Support Document.  



III. Summary of Benefits Assessment and Agency Evaluation of 

Comments and Additional Data Received  



   In the PD 2/3, EPA estimated that affected growers could 

lose in aggregate as much as $19 to $22 million per year as 

a result of the cancellation of arsenic acid. EPA received a 

number of comments on the benefits assessment. The most important 

general criticism was that EPA did not adequately assess the 

ripple effect on the local community if many growers left the 

cotton business. EPA carefully considered these comments. However, 

none of these comments contains data or specific information 

that would prove that EPA's estimate of benefits is greatly 

understated. Thus, EPA does not find it necessary to revise 

its benefits case. A detailed discussion of the comments on 

the benefits assessment of the PD 2/3 and EPA's response may 

be found in the Support Document.  

   In addition, the PD 2/3 was sent to the Secretary of Agriculture. 

The USDA/National Agricultural Pesticide Impact Assessment Program 

(NAPIAP) estimated losses ranging between $14 and $52 million, 

based on USDA and State assessments. They noted that EPA's estimate 

of $19 to $22 million was toward the lower end of their range. 

They noted the variability of arsenic acid use based on earliness 

of frost.  

   EPA carefully considered these comments. However, because 

the comments contained no data or details of how USDA made its 

estimates, EPA cannot evaluate their soundness. Thus, EPA does 

not feel its estimate is necessarily too low. EPA is well aware 

of the variability in frost dates from information contained 

in the Inorganic Arsenicals Assessment Team Report of 1980, 

and took this variability into account in developing its benefits 

assessment. These comments are considered in more detail in 

the Support Document.   



IV. Summary of Existing Stocks Provisions and Agency Evaluation 

of Comments and Additional Data Received  



   In the PD 2/3, EPA proposed to prohibit the sale, distribution, 

and use of existing stocks of arsenic acid after the final date 

of cancellation because risks outweighed the localized benefits. 

EPA received several comments both supporting and opposing this 

position. Several commenters opposed a prohibition on sale and 

use of existing stocks because the severe local economic impact 

could be eased by a phaseout. Other commenters supported the 

prohibition on sale and use of existing stocks because waste 

treatment costs resulting from processing arsenic acid treated 

cotton were unreasonably high. EPA considered these comments, 

but did not find them persuasive.  

   However, with regard to the registrants Atochem and VPG, 

EPA has determined to allow the sale and use of existing stocks 

of arsenic acid products through the 1993 use season because 

this action achieves the most favorable risk/benefit determination. 

The comments, EPA response, and EPA's decision is discussed 

in detail in the May 6, 1993 Notice of Voluntary Cancellation 

(58 FR 26975) and in the Support Document.  



V. Comments of the Scientific Advisory Panel and the Secretary 

of Agriculture  



   As required under Sections 6 and 25 of FIFRA, the Agency 

provided the PD 2/3 and technical support document to the Scientific 

Advisory Panel and the Secretary of Agriculture. Their comments 

and the EPA responses are summarized in Units II and III of 

this notice. In addition they are printed in full in the Support 

Document along with the EPA response.  



VI. Risk/Benefit Assessment and Decision Regarding Special Review 



   Prior to 1991, the Agency had completed the review of the 

inorganic arsenicals, including wood preservatives, and most 

non-wood preservatives except for five uses of arsenic acid, 

sodium arsenite, lead arsenate, and calcium arsenate. In the 

PD 2/3 for arsenic acid, the Agency proposed to conclude the 

Special Review of four of these uses, including the use of arsenic 

acid as a desiccant on okra grown for seed, sodium arsenite 

as a fungicide on grapes, lead arsenate as a plant growth regulator 

on grapefruit, and calcium arsenate as a herbicide on turf, 

leaving only arsenic acid as a desiccant on cotton remaining 

in Special Review. In today's notice, the Agency has responded 

to the comments received on the PD 2/3 for arsenic acid as a 

cotton desiccant, and the Agency has determined that it will 

not modify the risk/benefit assessment of arsenic acid on cotton, 

which was set forth in the PD 2/3. Further, the registrants 

have requested voluntary cancellation of their registrations 

for arsenic acid on cotton, and EPA has canceled them. Sale 

and use of existing stocks of Atochem and VPG arsenic acid cotton 

desiccant products will end after the 1993 use season. Therefore, 

the Agency is concluding the Special Review for the remaining 

non-wood preservative uses of the inorganic arsenicals: lead 

arsenate growth regulator on citrus, calcium arsenate on turf, 

sodium arsenite fungicide on grapes, and arsenic acid on okra 

and cotton.  



VII. Public Docket  



   Documents referred to in this Notice, including the Support 

Document, may be reviewed at the Public Docket (OPP-30000/29B), 

located at Room 1132, CM #2, 1921 Jefferson Davis Highway, Arlington, 

Virginia 22202. The Docket is open from 8:00 a.m. to 4:30 p.m., 

Monday-Friday. 



List of Subjects 



   Environmental protection. 



   Dated: November 24, 1993. 





Lynn R. Goldman, 

Assistant Administrator for Prevention, Pesticides and Toxic 

Substances. 



[FR Doc. 93-29716 Filed 12-7-93; 8:45 am]