United States
Environmental Protection
Agency
Prevention, Pesticides
And Toxic Substances
(7508W)
EPA-738-F-96-017
January 1997
R.E.D. FACTS
Pesticide
Reregistration
Trichlorfon
All pesticides sold or distributed in the United States must be
registered by EPA (the Agency), 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 reregi strati on, the Agency 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. The Agency then reregisters
pesticides that can be used without posing unreasonable risks to human
health or the environment.
When a pesticide is eligible for reregi strati on, the Agency explains the
basis for its decision in a Reregistration Eligibility Decision (RED)
document. This fact sheet summarizes the information in the RED
document for reregi strati on case 0104, Trichlorfon.
Use Profile
Trichlorfon is an insecticide that historically has been used to control
indoor and outdoor pests on agricultural, non-agricultural, residential and
commercial sites. Through the RED process many uses have been
voluntarily canceled. Those that are supported through reregi strati on
include indoor non-food uses in residential and commercial institutions to
control, among other pests, flies, roaches and ants. The outdoor uses of
trichlorfon include treatment to ornamentals, golf courses and residential
turf to control various Lepidopteran larvae pests. Also, trichlorfon may be
used in various agricultural farm premise sites, such as kennels, chicken
houses, dairy milking stalls and barns, but only in areas inaccessible to
animals; these uses are predominantly for fly control. Trichlorfon may also
be used as a mound treatment to control Harvester ants.
Trichlorfon may be formulated as a soluble powder, granular or bait.
Soluble powders may be applied through ground boom sprayers and hand-
held sprayers to turf and ornamentals or indoor spot treatments. Aerial
application is prohibited for trichlorfon. All turf uses of trichlorfon now
must include pre-treatment watering-in. The application of granular
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formulations with chest-mounted rotary spreaders are prohibited based on
potential health risks. Granular baits are used both indoors and outdoors by
scattering in problem areas. The bait is also used as a mound treatment to
control Harvester ants. The bait can no longer be used on residential lawns
and all indoor residential use of bait must be through a prepackaged child-
resistant bait station.
Regulatory Trichlorfon was first registered as a pesticide in the U.S. in 1955 by
History USD A. The Agency issued a Registration Standard for trichlorfon in June
1984. A 1991 Data Call-In (DCI) required additional data. Currently, 24
trichlorfon products are registered.
Human Health
Assessment
Toxicity
In studies using laboratory animals, trichlorfon generally has been
shown to be of moderate acute toxicity. It is moderate by the oral route and
has been placed in Toxicity Category II (the second highest of four
categories) for this effect. It is slightly toxic by the dermal route, Toxicity
Category III and practically non-toxic by the dermal route, Toxicity
Category IV. Trichlorfon causes moderate eye irritation, Toxicity Category
III. It is classified as a moderate contact allergen with skin effects classified
as Toxicity Category IV.
Dietary Exposure
People may be exposed to residues of trichlorfon through the diet.
Tolerances or maximum residue limits have been established for many
agricultural and livestock commodities (please see 40 CFR 180.198 and
186.2325). The Agency is proposing to revoke all tolerances for trichlorfon
except cattle meat, cattle fat and cattle meat by-products. The registrant is
not supporting the domestic use of the cattle treatment but will support the
tolerances needed for the continuing importation of trichlorfon treated cattle
products. In order to reassess the tolerances additional residue data are
required within 24 months. Residue and metabolism data are required to
reassess the tolerances, specifically, dermal metabolism in cattle (171-4b),
magnitude of the residue for meat (171-4J), residue analytical method
(171-4d), and storage stability (171-4e).
Occupational and Residential Exposure
Based on current use patterns, handlers (mixers, loaders, and
applicators) may be exposed to trichlorfon during and after normal use of
all formulations. The Agency has determined that there are unacceptable
risks posed to handlers in several use scenarios. In response to these
concerns, the registrant voluntarily canceled sod farm use and will prohibit
aerial application and application of granular formulations with chest-
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mounted rotary spreaders. Upon recommendation by the Agency, the
registrants have agreed to voluntarily cancel domestic lawn use with the
bait formulations. Also, indoor residential use of the bait formulation is
prohibited unless housed in prepackaged bait stations. Additional PPE was
required for handlers in other use scenarios.
Human Risk Assessment
Trichlorfon generally is of moderate acute toxicity and has been
classified as a Group E, no evidence of carcinogenicity for humans. All
trichlorfon food and feed crop uses have been voluntarily canceled. The
only dietary exposure to trichlorfon residues in foods will be through
imported cattle meat, cattle fat and cattle meat-by-products. However, the
theoretical maximum residue contribution (TMRC) to the two highest
exposed subgroups, children (1-6 years old) and non-nursing infants (< 1
year old) is relatively low, representing 14.33% and 7.32% of the RfD,
respectively. These estimates indicate the import of trichlorfon treated
cattle products does not present a chronic dietary risk.
The acute dietary exposure was estimated for the import of trichlorfon
treated cattle using established tolerances and was determined to be very
low. The estimated Margins of Exposure (MOEs) were greater than 10,
suggesting that there is little likelihood of an appreciable acute dietary risk
from the import of trichlorfon treated cattle products.
The Agency has determined that there is a concern for exposure to
children and pets from the indoor residential uses of the bait formulations.
In response, the Agency is requiring that all baits formulated for use inside
residential dwellings must be housed in child-resistant bait stations. Baits
not housed in child resistant packaging must include label statements
restricting use from indoor residential areas.
The Agency has determined that there are mitigatable risks associated
with mixer and loaders who handle the soluble powder formulation to
support typical area (40 acres per day) application to turfgrass. The risk can
be adequately mitigated with the additional PPE of chemical resistant
gloves. Also, the risk to commercial mixers/loaders/applicators handling the
granular formulation for application to turfgrass using push-type spreaders
could be adequately mitigated with the additional PPE of double layer
bodywear and chemical resistant gloves. The Agency also determined that
there was unacceptable risk posed to handlers in several other exposure
scenarios. In response to these concerns, the registrant voluntarily canceled
sod farm use and will prohibit aerial application and application of granular
formulations with chest-mounted rotary spreaders. Post-application reentry
workers will be required to observe a 24-hour Restricted Entry Interval.
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Environmental
Assessment
Environmental Fate
Potential for contamination of groundwater by trichlorfon and
trichlorfon degradates cannot be adequately assessed because acceptable
field dissipation data are not available. Potential to leach is suggested by
findings of high mobility in soil. Risk of contamination of surface and
ground water may be moderated by rapid degradation of trichlorfon in soil
and water. The major degradate in both soil and water is dichlorvos
(DDVP) with desmethyl DDVP also reported as a degradate in soil. DDVP
is itself a registered pesticide active ingredient.
Ecological Effects
On an acute basis, trichlorfon is highly toxic to moderately toxic to
birds. Trichlorfon subacute dietary toxicity is classified as moderately toxic
to practically non-toxic. Avian reproductive studies indicate that there will
be effects on reproduction at levels of trichlorfon as low as 30 mg/L.
Trichlorfon was determined to have low toxicity to honey bees.
Acute toxicity measurements with trichlorfon range from highly toxic
to practically non-toxic to freshwater fish. Chronic toxicity testing with fish
indicate that the maximum allowable toxicant concentration (MATC) for
trichlorfon is between 110 and 160 //g/L. Acute toxicity testing on aquatic
invertebrates indicate that trichlorfon is very highly toxic to all test species
except crayfish, to which it was found to be moderately toxic. Chronic
toxicity testing with aquatic invertebrates indicate that the MATC for
trichlorfon is between 5.6 and 8.6 ng/L.
Additional Data
p . j
Ecological Risk Assessment
Based on the exposure from the turf uses, acute risk levels of concern
are exceeded for freshwater, marine and estuarine fish and invertebrates and
birds. Chronic risk levels of concern are exceeded for freshwater
invertebrates and birds. The registrant has agreed to require buffer strips
from aquatic habitats, mandatory watering-in for turf sites to reduce surface
run-off, the prohibition of aerial application which can result in spray drift
and the prohibition of residential lawn use with the bait formulations.
These measures will greatly reduce the exposure of aquatic habitats to
trichlorfon as well as reduce the residues available for dietary consumption
by birds. The acreage of trichlorfon usage has also been reduced by the
cancellation of all field crops and sod farm use. The Agency has
determined that although levels of concern are exceeded for non-target
organisms, the exposure has been adequately mitigated.
^e Agency 1S requiring the following additional generic studies for
trichlorfon to confirm its regulatory assessments and conclusions: estuarine
or marine mollusk acute toxicity study (72-3b), life cycle aquatic
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invertebrate (72-4b), terrestrial field dissipation (164-1), evaluation of
worker exposure from hydraulic low pressure handwand application (231
and 232) and worker reentry exposure from turf and greenhouse use (132-1,
133-3 and 133-4), droplet size spectrum (201) and drift field evaluation
(202-1). Residue and metabolism data are required to reassess the cattle
meat, cattle fat and cattle meat-by-products tolerances (171-4b, 171-4d,
171-4e, 171-4J).
The Agency also is requiring product-specific data including product
chemistry and acute toxicity studies, revised Confidential Statements of
Formula (CSFs), and revised labeling for reregi strati on.
Product Labeling All trichlorfon end-use products must comply with the Agency's
ChariQGS current pesticide product labeling requirements and with the following. For
Red III red a comPrehensrve list of labeling requirements, please see the trichlorfon
RED document.
PPE/Engineering Control Requirements for Pesticide Handlers
For sole-active-ingredient end-use products that contain trichlorfon,
the product labeling must be revised to adopt the handler personal
protective equipment/engineering control requirements set forth in this
section. Any conflicting PPE requirements on the current labeling must be
removed.
Products Intended Primarily for Occupational Use (WPS and
nonWPS)
Minimum (Baseline) PPE/Engineering Control Requirements
At this time there are no engineering control requirements, such as
closed systems, currently required on labeling for trichlorfon products, the
Agency is not establishing active-ingredient-based minimum (baseline)
engineering control requirements for trichlorfon end-use products that are
intended primarily for occupational use.
The Agency is establishing minimum (baseline) PPE for some
occupational uses of trichlorfon.
For soluble powder formulations:
"Mixers and loaders must wear:
—long-sleeve shirt and long pants,
—chemical-resistant gloves*, and
—shoes plus socks,
Applicators and other handlers (other than mixers and loaders) must
wear:
—long-sleeve shirt and long pants,
—shoes plus socks.
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For granular formulations:
Applicators and other handlers must wear:
—coveralls over long-sleeve shirt and long pants,
—chemical-resistant gloves*, and
—chemical-resistant footwear.
For readv-to-use formulations:
Applicators and other handlers must wear:
—long-sleeve shirt and long pants,
—chemical-resistant gloves*, and
—shoes plus socks.
*For the glove statement, use the statement established for trichlorfon
through the instruction in Supplement Three of 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) personal protective equipment specified above.
The more protective PPE must be placed on the product labeling. For
guidance on which PPE is considered more protective, see PR Notice 93-7.
Placement in Labeling
The personal protective equipment requirements 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.
Products Intended Primarily for Homeowner Use
Minimum (Baseline) PPE Requirements
The Agency is not establishing active-ingredient-based minimum
(baseline) handler PPE for trichlorfon end-use products that are intended
primarily for homeowner use.
Determining PPE Requirements for End-Use Product Labels
Any necessary PPE for each trichlorfon end-use product intended
primarily for homeowner use will be established on the basis of the end-use
product's acute toxicity category.
Placement in Labeling
The personal protective equipment requirements, if any, must be
placed on the end-use product labeling immediately following the
precautionary statements in the labeling section "Hazards to Humans (and
domestic animals)."
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Entry Restrictions
For sole-active-ingredient end-use products that contain trichlorfon
the product labeling must be revised to adopt the entry restrictions set forth
in this section. Any conflicting entry restrictions on the current labeling
must be removed.
Products Intended Primarily for Occupational Use
WPS Uses
Restricted-entry interval: A 24-hour restricted-entry interval (REI) is
required for uses within the scope of the WPS on all trichlorfon end-use
products.
"Exception: if the product is soil-injected or soil-incorporated
(including watering-in), the Worker Protection Standard, under
certain circumstances, allows workers to enter the treated area if there
will be no contact with anything that has been treated."
Early-entry personal protective equipment (PPE): The PPE required for
early entry is:
— coveralls over long-sleeve shirt and long pants,
— chemical-resistant gloves,
— chemical-resistant footwear plus socks.
Placement in labeling: The REI and the PPE required for early entry must
be inserted into the standardized REI statement required by Supplement
Three of PR Notice 93-7.
NonWPS uses
Entry restrictions: The Agency is establishing the following entry
restrictions for nonWPS occupational uses of trichlorfon end-use products:
• For liquid applications:
"Do not enter or allow others to enter the treated area until sprays
have dried."
• For granular applications:
"Do not allow people or pets to enter the treated area (except those
involved in the watering) until the watering-in is complete and the
surface is dry."
• For bait applications:
There are no entry restrictions.
Placement in labeling:
If WPS uses are also on label — Follow the instructions in PR Notice 93-7
for establishing a Non-Agricultural Use Requirements box, and place the
appropriate nonWPS entry restrictions in that box.
If no WPS uses are on the label — Place the appropriate nonWPS entry
restrictions in the Directions for Use, under the heading "Entry
Restrictions".
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Products Intended Primarily for Homeowner Use
Entry restrictions: The Agency is establishing the following entry
restrictions for all homeowner uses of trichlorfon end-use products:
• For liquid applications:
"Do not allow people or pets to enter the treated area until sprays have
dried."
• For granular applications:
"Do not allow people or pets to enter the treated area (except those
involved in the watering) until the watering-in is complete and the
surface is dry."
Placement in labeling: Place the appropriate entry restrictions in the
Directions for Use, under the heading "Entry Restrictions".
Other Labeling Requirements
Products Intended Primarily for Occupational Use
The Agency is requiring the following labeling statements be located
on all end-use products containing trichlorfon that are intended primarily
for occupational use:
Application Restrictions:
For all formulations:
"Do not apply this product in a way that will contact workers or other
persons, either directly or through drift. Only protected handlers may
be in the area during application."
"Aerial application is prohibited."
For granular formulations only:
"Apply with push-type granular spreaders only. Chest-mounted
rotary spreader ("belly-grinder") application equipment is prohibited."
User Safety Requirements:
(Registrant: select this 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.
(Registrant: select this 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."
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• "Users should remove PPE immediately after handling this
product. Wash the outside of gloves before removing. As soon
as possible, wash thoroughly and change into clean clothing."
Skin Sensitizer Statement:
"This product may cause skin sensitization in some people."
Engineering Controls:
"When handlers use closed systems, or enclosed cabs in a manner that
meets the requirements listed in the Worker Protection Standard
(WPS) for agricultural pesticides (40 CFR 170.240(d)(4-6), the
handler PPE requirements may be reduced or modified as specified in
the WPS."
Products Intended Primarily for Home Use
Application Restrictions
"Do not apply this product in a way that will contact any person
or pet, either directly or through drift. Keep people and pets out
of the area during application."
"Do not apply this product using "chest mounted rotary-type
spreader" application equipment."
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."
(Select this only if gloves and/or protective eyewear are required for
homeowner users:}
• "Users should remove protective clothing and equipment
immediately after handling this product. Wash the outside
of gloves before removing. Keep and wash protective
clothing and equipment separately from other laundry."
Skin Sensitizer Statement
"This product may cause skin sensitization reactions in some
people."
Environmental Hazard Statements
All labels must have standard language, including:
"Do not apply directly to water, or to areas where surface water is
present or to intertidal areas below the mean high water mark."
"Do not contaminate water by cleaning of equipment or disposal or
wastes."
"Do not apply when turf grass areas are water logged or the soil is
saturated with water (i.e. will not irrigate)."
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"Avoid run-off or puddling of irrigation water following application."
Soluble powders:
"Do not apply when average wind speeds are greater than 15 mph."
"Apply product using spray nozzles which produce a coarse droplet
size, such as flood jet nozzles or lawn care gun."
For Golf course Use:
"Do not apply within 25 feet of lakes, reservoirs, rivers, permanent
streams, marshes natural ponds, or estuaries."
"Post-application watering-in is required."
For Other Turf/Lawn Uses:
"Post-application watering-in is required."
Premise Precautions
All products labeled for use in livestock premise or areas must include
the following:
"Remove animals before using products as a premise spray treatment
in barns."
"Do not treat areas such as drinking cup, mangers, or troughs where
livestock feed."
"Do not contaminate water, food, feedstuffs, food or feed handling
equipment, or milk or meat handling equipment."
"Do not apply bait or spray to areas accessible to animals."
All products labeled for use in indoor residential or commercial
establishments must include:
"For use in non-food/non-feed areas."
"Do not contaminate food/feed or food/feed handling equipment."
"Do not use in the food/feed areas of food/feed handling
establishments. Do not use in edible product areas of food or feed
processing plants, restaurants or other areas where food or feed is
commercially prepared for processed. Do not use in restaurant
serving areas while food is exposed."
All bait formulation products not housed in child-resistant bait
stations must include the following:
"Not for Indoor Residential Use" and
"Not for Lawn/Turf Use".
All products labeled for use as a mound treatment for Texas Harvest
Ants must include the following:
"Apply only by hand-broadcast."
All products containing the site "area treatment" must be modified to
"nonfood/nonfeed areas".
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Regulatory
Conclusion
The use of currently registered products containing trichlorfon,
labeled for non-food uses as specified in the RED, will not pose
unreasonable risks or adverse effects to humans or the environment.
Therefore, all uses of these products with approved labeling, are eligible for
reregi strati on.
For More
Information
Trichlorfon products will be reregistered once the required product-
specific data, revised Confidential Statements of Formula, and revised
labeling are received and accepted by the Agency.
The Agency is requesting public comments on the Reregi strati on
Eligibility Decision (RED) document for trichlorfon 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, GOPHER.EPA.GOV, or using ftp on FTP.EPA.GOV, or using
WWW (World Wide Web) on WWW.EPA.GOV.
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 trichlorfon RED document also
will be available from the National Technical Information Service (NTIS),
5285 Port Royal Road, Springfield, VA 22161, telephone 703-487-4650.
For more information about EPA's pesticide reregi strati on program,
the trichlorfon RED, or reregi strati on of individual products containing
trichlorfon, 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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