United States
Environmental Protection
Prevention, Pesticides
And Toxic Substances
EPA-738-F-94-022
September 1994
R.E.D. FACTS
Pesticide
Registration
M-Cresol and Xylenol
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 years ago be reregistered to ensure that they meet
today's more stringent standards.
In evaluating pesticides for reregi strati on, EPA obtains and reviews a
complete set of studies from pesticide producers, describing the human
health and environmental effects of each pesticide. The Agency imposes
any regulatory controls that are needed to effectively manage 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 reregi strati on, EPA announces this and
explains why in a Reregi strati on Eligibility Decision (RED) document. This
fact sheet summarizes the information in the RED for m-cresol and xylenol,
cases 4027 and 4098, which are formulated together to produce a single
pesticide product called Gallex.
Use Profile
Regulatory
History
M-cresol and xylenol, when formulated together, have bacteriostatic
activity against the causal agents of crown gall and olive knot on fruit,
ornamental and shade trees and ornamental woody shrubs and vines and
control of the genetic/physiological disorder, burr knot, on apples. The
pesticide product that contains these two active ingredients, Gallex, is a
ready-to-use liquid that is brushed or painted onto the infected areas of trees
and ornamentals. Treatments may be made every 4 to 6 months, or about
twice a year. Although usage data are not available, EPA assumes that the
volume of use is relatively low.
M-cresol and xylenol were first registered for use as pesticides in the
U. S. in 1980. Their initial registration was for a use pattern similar to that
of the currently registered product, Gallex. Gallex contains the two active
ingredients at a very low concentration (only 0.46% of each).
Human Health
Assessment
Cresols (m-cresol and two other isomers) are present at low
concentrations in various environmental media including air, car exhaust,
wood and coal. Reports that cresols may have tumor promoting activity
have not been substantiated by scientific studies. Only acute and subchronic
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toxicity and mutagenicity studies are required for reregi strati on of m-cresol
and xylenol because of their current use patterns.
Toxicity
Technical grade m-cresol causes severe eye and skin irritation and has
been placed in Toxicity Category I, indicating the greatest degree of acute
toxicity, for these effects. Technical xylenol also is corrosive to the skin,
and has been placed in Toxicity Category I for this effect.
The end use product that contains both m-cresol and xylenol has been
found to cause slight eye irritation in rabbits and has been assigned to
Toxicity Category II for eye effects. It has been found to produce skin
sensitization in guinea pigs but does not cause skin irritation in rabbits.
Subchronic toxicity studies by the National Toxicology Program
(NTP) of the National Institutes of Health on m-cresol alone and with p-
cresol, a related isomer, indicated effects to the kidneys, liver and other
organs in rats and mice, particularly at high doses. A dermal study using
the formulated product on rabbits showed the product to be corrosive to
skin.
M-cresol does not cause developmental toxicity, but causes effects on
body and organ weights in reproductive toxicity studies using rats and mice.
M-cresol is not mutagenic, and is excreted through urine.
Dietary Exposure
Since m-cresol and xylenol are applied only to the bases of fruit and
nut trees, no residues are expected to remain in food or feed commodities.
The Agency is requesting the registrant seek an exemption from tolerance
(enforceable residue limit).
Occupational and Residential Exposure
Applicators may be exposed to m-cresol and xylenol when applying
the end-use product Gallex by paint brush to infected areas of trees and
ornamentals. Direct dermal and eye exposures to this product are
considered potentially significant because the active ingredients have a high
degree of acute toxicity to the eyes and skin. The formulated product
Gallex is also considered to be a dermal sensitizer. Use of personal
protective equipment (PPE) may mitigate the acute toxicity risks to
applicators.
Since no more than four consecutive days of occupational/residential
exposure are typically expected, a short term occupational/residential
margin of exposure (MOE) was calculated for m-cresol based on maternal
toxicity. The MOE for the end-use product, estimated to be 1,017, is
acceptable. The Agency also considered intermediate term exposure due to
the potential that commercial applicators may be exposed to the end-use
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product for this interval. The intermediate term exposure assessment was
based on a 28-day feeding study. The less likely intermediate term exposure
revealed a MOE for the end-use product at 308, an acceptable level. There
are no post-application worker exposure concerns.
Human Risk Assessment
Dietary exposure to m-cresol and xylenol is not a concern since
residues of these pesticides do not remain in the fruit or nuts of treated
trees. Applicators face acute toxicity hazards to the skin and eyes.
However, these risks will be mitigated by use of PPE, as required by the
RED. Considering Gallex's use pattern, the low concentration of each
active ingredient in the end use product, the toxicity characteristics of these
chemicals, and the acceptable MOE, EPA does not expect significant health
risks from short term or intermediate term residential/occupational exposure
to m-cresol and xylenol, when used properly as directed.
EPA did not conduct an environmental risk assessment for m-cresol
and xylenol and did not require any data on environmental fate or
ecotoxicity The current use pattern of these pesticides and their low
volume of use will result in very low environmental exposure, resulting in
no threat to wildlife. Non-target organisms including endangered species
are not expected to be adversely affected from this use.
Additional Data EPA is requiring product specific data including product chemistry
Required anc^ acute toxicity studies, a revised Confidential Statement of Formula and
revised labeling for reregi strati on of m-cresol and xylenol.
Product Labeling The label of the registered pesticide product containing m-cresol and
Changes Required xylenol must comply with EPA's current pesticide labeling requirements.
In addition, Personal Protective Equipment (PPE) must be required on
product labeling, as follows:
"Applicators and other handlers must wear: protective eyewear,
chemical resistant gloves, long sleeves, long pants, shoes and socks."
Environmental
Assessment
Regulatory
Conclusion
Use of the currently registered pesticide product containing m-cresol
and xylenol in accordance with approved labeling will not pose unreasonable
risks or adverse effects to humans or the environment. Therefore, all uses
of these pesticides are eligible for reregi strati on. The product Gallex will
be reregistered once the required product specific data, Confidential
Statement of Formula and revised labeling are received and accepted by
EPA.
For More EPA is requesting public comments on the Reregi strati on Eligibility
Decision (RED) document for m-cresol and xylenol during a 60-day time
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Information 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.
Following the comment period, the m-cresol and xylenol RED
document 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 m-cresol and xylenol RED, or reregi strati on of the end-use product
containing m-cresol and xylenol, please contact the Special Review and
Reregistration 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 8:00 am and 6:00 pm Central Time, Monday
through Friday.
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