United States
Environmental Protection
Agency
Prevention, Pesticides
And Toxic Substances
(7508W)
EPA-738-F-96-028
September 1995
R.E.D. FACTS
Pesticide
Reregistration
Use Profile
Regulatory
History
Bis(trichloromethyl)
sulfone
All pesticides sold or distributed in the United States must be
registered by EPA, based on scientific studies showing that they can be used
without posing unreasonable risks to people or the environment. Because of
advances in scientific knowledge, the law requires that pesticides which
were first registered before November 1, 1984, be reregistered to ensure that
they meet today's more stringent standards.
In evaluating pesticides for reregistration, EPA obtains and reviews a
complete set of studies from pesticide producers, describing the human
health and environmental effects of each pesticide. The Agency develops
any mitigation measures or regulatory controls needed to effectively reduce
each pesticide's risks. EPA then reregisters pesticides that can be used
without posing unreasonable risks to human health or the environment.
When a pesticide is eligible for reregistration, EPA explains the basis
for its decision in a Reregistration Eligibility Decision (RED) document.
This fact sheet summarizes the information in the RED document for
reregistration case 2055, bis(trichloromethyl) sulfone.
Bis(trichloromethyl) sulfone is used to control microbes, algae, and
fungi in cooling water systems, waste disposal systems, pulp and paper mill
water systems, oil extraction systems, and other industrial settings
(adhesives, industrial coatings, industrial emulsions, etc.). Formulations
include soluble concentrated liquids, ready-to-use liquids, and soluble
concentrated solids. These products are added to systems and industrial
products using pouring and pumping methods. Product labeling includes
National Pollutant Discharge Elimination System (NPDES) license
requirements.
Bis(trichloro)methyl sulfone was first registered in the U.S. in 1967 as
a fungicide. In 1968, another registration was issued for a
bis(trichloromethyl) sulfone product with additional biocide uses. Currently
there are five companies with fourteen products. One of these products is
registered as a technical with an active ingredient declaration of 98%. The
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others are end-use products containing from 2.5% to 49%
bis(trichloromethyl) sulfone.
In 1987 the Agency issued the Antimicrobial Data Call-in Notice to
obtain additional chronic and subchronic toxicity data for this and other
antimicrobial chemicals.
Human Health Toxicity
Assessment Bis(trichloromethyl) sulfone is slightly toxic to non-toxic in acute oral
and dermal toxicity tests. However, it is highly toxic in eye irritation,
dermal irritation, and inhalation acute toxicity studies.
In an acute neurotoxicity study with rats, decreased food
consumption, body weights, core body temperatures, and motor activity
were observed in the low dose animals. In a subchronic dermal rabbit
toxicity study changes in the blood and clinical chemistry values occurred.
In developmental studies in the rat and rabbit, signs of maternal toxicity
included decreased body weight gains and reduced food consumption.
Incidences of clinical toxicity were observed in maternal rabbits at the mid-
dose. Although no developmental treatment-related effects were noted in
rabbits, decreased fetal body, skeletal, and external abnormalities were
identified in the mid-dose animals. Evidence of mutagenicity was observed
in several studies. Because the findings were equivocal in the gene
mutation study, an assay that involves animal germ cells is required.
Dietary Exposure
Tolerances or residue limits are established for bis(trichloromethyl)
sulfone in adhesives, paper and paper products which may contact food.
These uses of bis(trichloromethyl) sulfone in the manufacture of paper,
paperboard (21 CFR §176.300) and adhesives (21 CFR §175.105) which
may contact food are regulated by the U.S. Food and Drug Administration
(FDA). There are no other registered food uses of bis(trichloromethyl)
sulfone.
Occupational and Residential Exposure
Based on the current use patterns, handlers (mixers, loaders, and
applicators) may be exposed to bis(trichloromethyl) sulfone during and after
normal use of the liquid and solid soluble concentrates and the ready-to-use
liquid formulations. An exposure assessment is appropriate based on the
toxicological endpoints from the subchronic dermal and developmental
toxicity studies in the rat.
Several exposure scenarios were considered in the Agency's exposure
assessment, including both open and closed application systems. Data
suggest that for the estimation of dermal exposures were appropriate. As
expected, exposures to handlers were greatest from open systems,
particularly in cooling water and oil drilling muds/packer fluid applications.
For these scenarios, margins of exposure (MOEs) were less than 100 for
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Environmental
Assessment
both the short-term and intermediate term exposures. An MOE of less than
100 is of concern to the Agency.
To mitigate these risks to handlers, EPA is requiring use of a closed
system for loading and application in water cooling systems and oil drilling
muds/packer fluid scenarios. For all other uses of bis(trichloromethyl)
sulfone, baseline personal protective equipment (PPE) equivalent to those
worn in the exposure study are required.
Although exposures to workers in areas where bis(trichloromethyl)
sulfone has recently been applied are expected, EPA believes that these
exposures would be significantly less than those for handlers applying the
pesticide.
There are no bis(trichloromethyl) sulfone products labeled for
homeowner use. Exposures to homeowners may occur from products, such
as adhesives or paper products, treated with bis(trichloromethyl) sulfone.
Again, the Agency believes that these exposures would be minimal.
Human Risk Assessment
Bis(trichloromethyl) sulfone was determined to be highly toxic in eye
irritation, dermal irritation and inhalation acute toxicity studies, but was
slightly toxic to non-toxic in other acute toxicity tests.
The use of bis(trichloromethyl) sulfone in the manufacture of paper,
paperboard, and adhesives which may contact food are regulated by FDA.
There are no other registered food uses.
The Agency is concerned for exposures to bis(trichloromethyl)
sulfone in the workplace, especially for handlers open-pouring the pesticide
in cooling water and oil drilling mud/packer fluid applications. To protect
these workers, the Agency is requiring closed system loading and
application methods. Baseline PPE is required for other uses of
bis(trichloromethyl) sulfone.
Environmental Fate
Marginal data are available to estimate the environmental fate of
bis(trichloromethyl) sulfone. These data suggest that the primary route of
dissipation is through microbial action, with a half-life of less than 0.5 days.
Ecological Effects
Bis(trichloromethyl) sulfone is practically non-toxic to birds, and
highly to very highly toxic to freshwater and estuarine/marine organisms.
Ecological Effects Risk Assessment
While the hazard to aquatic organisms from bis(trichloromethyl)
sulfone has been characterized, a quantitative risk assessment has not been
conducted. The risks to aquatic environments from this use are regulated
under the NPDES permitting program of EPA's Office of Water. The
Agency currently requires that labels for all bis(trichloromethyl) sulfone
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products require that discharges to aquatic environments comply with an
NPDES permit.
Risk Mitigation
Additional Data
Required
Product Labeling
Changes
Required
To lessen the risks posed by bis(trichloromethyl) sulfone, EPA is
requiring the following risk mitigation measures.
• EPA is requiring meter-pump loading and application of
bis(trichloromethyl) sulfone for the following uses:
pasteurizer/warmer/cannery cooling water systems, commercial/
industrial water cooling systems, evaporative-condenser water
systems, heat-exchanger water systems, and oil recovery drilling
muds/packer fluids.
• The Agency is establishing active ingredient based minimum PPE
requirements for primary occupational handlers. Since all the MOEs
generated are based on units of exposure from the Chemical
Manufacturers Association exposure study in which handlers wore
chemical resistant gloves, such chemical-resistant gloves are required
for occupational handlers of bis(trichloromethyl) sulfone.
EPA is requiring additional generic information for
bis(trichloromethyl) sulfone to confirm its regulatory assessments and
conclusions, including an acute neurotoxicity study in rats, gene mutation
study, and a sister chromatid exchange study.
Data generated by the Antimicrobial Task Force of the Chemical
Manufacturers Association have been used to address these exposures in the
bis(trichloromethyl) sulfone RED document; however, the Agency requires
offers of compensation be made for the use of these data or new, adequate
data be submitted. A Data Call-in has been issued to the registrants of
bis(trichloromethyl) sulfone requiring these actions.
All bis(trichloromethyl) sulfone end-use products must comply with
EPA's current pesticide product labeling requirements and with the
following.
• PPE/Engineering Control Requirements for Pesticide Handlers
For sole-active-ingredient end-use products that contain
bis(trichloromethyl) sulfone, the product labeling must be revised to
adopt the handler personal protective equipment (PPE)t/engineering
control requirements set forth below. Any conflicting
PPE/engineering control requirements on the current labeling must be
removed.
For multiple-active-ingredient end-use products that contain
bis(trichloromethyl) sulfone, the PPE/control requirements set forth in
this section must be compared to the requirements on the current
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labeling and the more protective must be retained. For guidance on
which requirements are considered more protective, see PR Notice
93-7.
(1) Minimum (Baseline) Engineering Control Requirements
Products with bis(trichloromethyl) sulfone must be labeled to
require pump engineering controls during loading and
application for the following uses: oil recovery drilling
muds/packer fluids, pasteurizer/warmer/cannery cooling water
systems, commercial/industrial water cooling systems,
evaporative-condenser water systems, and heat exchanger water
systems.
In the "Directions For Use" portion of the label referring to
these uses, registrants must insert the following language:
"This product must be loaded and applied only using a
meter-pump system or a closed loading/application system
for the following uses: (list uses}. Open pouring is
prohibited."
(2) Minimum (Baseline) Personal Protective Equipment
Requirements
EPA is establishing active-ingredient-based minimum (baseline)
PPE for bis(trichloromethyl) sulfone end-use products that are
intended for occupational use. Product labels must be amended
to include the following statement:
"Applicators and other handlers must wear: chemical
resistant gloves, long pants, a long sleeved shirt, shoes and
socks."
Placement in labeling: The PPE must be placed on the end-use
product labeling in the location specified in PR Notice 93-7 and the
format and language of the PPE requirements must be the same as is
specified in PR Notice 93-7.
Determining PPE Requirements for End-Use Product Labels:
The PPE that would be established on the basis of the acute toxicity
category of the end-use product must be compared to the active-
ingredient-based minimum (baseline) PPE specified above. The more
protective PPE must be placed on the product labeling. For guidance
on which PPE is considered more protective, its placement, format,
and wording refer to PR Notice 93-7. NOTE: If the end-use product
is classified as toxicity category I or II for eye irritation potential,
protective eyewear is also required.
The Agency is requiring the following labeling statements to be
located on all end-use products containing bis(trichloromethyl)
sulfone that are intended primarily for occupational use.
Application Restrictions
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"Do not apply this product in a way that will contact
workers or other persons."
User Safety Requirements
—Registrants: add the following statements if coveralls are
required for pesticide handlers on the end-use product label:
"Discard clothing or other absorbent materials that have
been drenched or heavily contaminated with this product's
concentrate. Do not reuse them."
—Registrants: add the following statements always:
"Follow manufacturer's instructions for
cleaning/maintaining PPE. If no such instructions for
washables, use detergent and hot water. Keep and wash
PPE separately from other laundry."
User Safety Recommendations
• "Users should wash hands before eating, drinking, chewing
gum, using tobacco, or using the toilet."
• "Users should remove clothing immediately if pesticide
gets inside. Then wash thoroughly and put on clean
clothing."
• "Users should remove PPE immediately after handling this
product. Wash the outside of gloves before removing. As
soon as possible wash thoroughly."
To clarify the intent of the oil recovery drilling muds/packer fluids use
(as an indoor or outdoor use pattern) the following statement must be
added to the labels for terrestrial non-food oil/gas drilling muds and
packer fluids:
"For use on terrestrial oil wells only."
And the following statement must be added to the precautionary
labeling:
"Do not apply in marine and/or estuarine oil fields."
The following statement must be added to the labels for aquatic non-
food industrial drilling muds and packer fluids:
"For use on offshore oil wells only."
For use in both terrestrial and offshore oil drilling muds and packer
fluids, the following statement must be added:
"This product may be used for terrestrial and offshore oil
drilling muds and packer fluids."
Registrants must specify on labeling the complete directions for use
for each use pattern: site of application, type of application, timing of
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application, equipment used for application, and the rate of
application (dosage).
• To clarify that water cooling uses do not include once-through
systems, the following statement must be added:
"This product may not be used in once-through cooling
systems."
For a comprehensive list of labeling requirements, please see the
Bis(trichloromethyl) sulfone RED document.
Regulatory
Conclusion
For More
Information
The use of currently registered products containing
bis(trichloromethyl) sulfone in accordance with approved labeling and as
described in the Reregi strati on Eligibility Document will not pose
unreasonable risks or adverse effects to humans or the environment.
Therefore, all uses of these products are eligible for reregi strati on.
Bis(trichloromethyl) sulfone products will be reregistered once the
required product-specific data, confirmatory generic data, revised
Confidential Statements of Formula, and revised labeling are received and
accepted by EPA.
EPA is requesting public comments on the Reregi strati on Eligibility
Decision (RED) document for bis(trichloromethyl) sulfone during a 60-day
time period, as announced in a Notice of Availability published in the
Federal Register. To obtain a copy of the RED document or to submit
written comments, please contact the Pesticide Docket, Public Response
and Program Resources Branch, Field Operations Division (7506C), Office
of Pesticide Programs (OPP), US EPA, Washington, DC 20460, telephone
703-305-5805.
Electronic copies of the RED and this fact sheet can be downloaded
from the Pesticide Special Review and Reregi strati on Information System
at 703-308-7224. They also are available on the Internet on EPA's gopher
server, GOPHEREPAGOV, or using ftp on FTP.EPAGOV, or using
WWW (World Wide Web) on WWW.EPAGOV.
Printed copies of the RED and fact sheet can be obtained from EPA's
National Center for Environmental Publications and Information
(EPA/NCEPI), PO Box 42419, Cincinnati, OH 45242-0419, telephone 513-
489-8190, fax 513-489-8695.
Following the comment period, the [name] RED document also will
be available from the National Technical Information Service (NTIS), 5285
Port Royal Road, Springfield, VA 22161, telephone 703-487-4650.
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For more information about EPA's pesticide reregi strati on program,
the bis(trichloromethyl) sulfone RED, or reregi strati on of individual
products containing bis(trichloromethyl) sulfone, please contact the Special
Review and Reregi strati on Division (7508W), OPP, US EPA, Washington,
DC 20460, telephone 703-308-8000.
For information about the health effects of pesticides, or for assistance
in recognizing and managing pesticide poisoning symptoms, please contact
the National Pesticides Telecommunications Network (NPTN). Call toll-
free 1-800-858-7378, between 9:30 am and 7:30 pm Eastern Standard Time,
Monday through Friday.
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