Questions And Answers On Lawn Pesticides
Questions And Answers On Lawn Pesticides
- What Chemicals are registered for home lawn use?
- What data are required for evaluation of lawn chemicals?
- Why aren't data routinely required to evaluate their
- How frequently are lawns treated?
- What is EPA doing to improve regulation of pesticides used
- How many pesticide incidents attributed to lawn care
pesticides have been reported to EPA?
- Can Integrated Pest Management help maintain home lawns and
reduce risk from pesticide exposure?
- Should homeowners know more about pesticides use on lawns?
- Isn't posting of lawns an important step to take?
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, DC 20460
For Your Information
The use of pesticides on lawns is gaining increased public visibility and
corresponding concerns. The attached information may be helpful in answering
some of the concerns that are certain to surface from pesticide users, lawn
service customers, news media and other interested groups. Any questions not
covered in the attached paper may be directed to Thomas Adamczyk at
Anne Lindsay, Director
1. What Chemicals are registered for home lawn use?
There are 223 chemicals that have home lawn uses. The large majority are
used infrequently. We estimate that 35 active ingredients are used in over 90%
of lawn treatments. (See attachment #1
2. What data are required for evaluation of lawn chemicals?
Lawn pesticides fall under the category of terrestrial nonfood use. The
following data are required to evaluate the toxicity of such products:
- Acute oral toxicity - rat
- Acute dermal toxicity - rabbit
- Acute inhalation toxicity - rat
- Primary eye irritation - rabbit
- Primary dermal irritation -- rabbit
- Dermal sensitization - guinea pig
- Acute delayed neurotoxicity - hen (only for organophosphates or compounds
structurally related to substances that cause delayed neurotoxicity).
These data on the acute effects of lawn care pesticides are used to evaluate
potential hazards that may be associated with the short term or intermittent
exposure that results from their use. Highly acutely toxic pesticides are not
registered for home lawn use.
Although the above requirements are those listed as minimum toxicity
requirements, the chemical structure of new lawn pesticides has often led EPA to
require additional studies such as oncogenic, teratogenic and subacute dermal
and inhalation data.
3. Why aren't data routinely required to evaluate their longterm toxicity?
Since exposure to lawn care pesticides does not occur on a routine basis
over long periods of time, the Agency has not routinely required chronic
toxicity data to evaluate potential hazards. However, because the majority of
the primary lawn care chemicals (29 out of the 35) also are used on food or feed
crops, the Agency does have more extensive data bases for these chemicals
including sub-chronic and chronic toxicity data. Most of these 35 pesticides are
included in the Agency's program to reevaluate older pesticides. To date,
Registration Standards have been issued for 17 of them and the remainder of the
old lawn care chemicals will be reevaluated as the Agency completes its
4. How frequently are lawns treated?
Homeowners and residents are not likely to receive long term or chronic
exposure to these pesticides. Even intensively managed lawns receive, in most
areas of the U.S., a maximum of five pesticide applications a year and the
maximum number of applications of any one active ingredient is two. Below is an
example of treatments applied by lawn care companies for a home lawn in the
temperate areas of the U.S.
- Early spring - Pre-emergence crabgrass treatment (Balan, Dacthal,Betasan).
- Late spring, early summer - Broad leaf weed control (2,4-D, dicamba, MCPP).
- Mid-summer insect control - For chinch bug and/or grub control (Triumph,
Oftanol, Diazinon, Chlorpyrifos)
- Fall weed treatment - (2,4-D, dicamba, MSMA).
In addition to the above, some humid areas of the country may receive one or
more fungicide treatments for control of lawn diseases. From the above, it is
apparent that only the broadleaf control herbicides routinely are involved in
more than one application per year.
5. What is EPA doing to improve regulation of pesticides used on lawns?
In addition to its reevaluation of individual pesticides, EPA is currently
reexamining its data requirements for these types of pesticides. In particular,
the Agency's current methods for estimating exposure, including exposure to
children, most likely overestimate exposure. An experimental protocol for indoor
pesticides has been developed jointly by EPA, the California Department of Food
and Agriculture, Health and Welfare-Canada, and the National Agricultural
Chemicals Association. Further research with this protocol would allow
development of mathematical models that could generate more refined exposure
estimates for lawn pesticides. The Agency is also considering whether to require
additional subchronic toxicity data for these types of pesticides and additional
chemical-specific exposure data which could be used when the mathematical models
have been developed.
6. How many pesticide incidents attributed to lawn care pesticides have been
reported to EPA?
EPA has no firm data on the number of proven incidents, but based on
available information, believes that the incidents may be quite low, and
primarily involve misuse of a product where the product was not applied
correctly or those affected did not wait until the application was dry before
re-entering. Generally children and pets have the greatest potential danger if
these products are misused. In addition, the Agency has received reports of some
incidents where extremely sensitive individuals have apparently had adverse
reactions from exposure to treated lawns.
There are also incidents of injury to desirable trees, shrubs and flowers from
use of pesticides through drift, volatility and improper application. The
herbicide labels however, warn the user of these effects and provide instruction
on ways to minimize the likelihood of those events occurring.
Yes. EPA developed an integrated pest management plan (IPM) that involves
minimal pesticide use and will enable homeowners to have healthy, attractive
lawns. In properly maintained lawns the thick healthy turf will crowd out most
weed species and will not be severely affected by most common outdoor insects.
If the lawn is cut at the proper height, watered and fertilized properly, the
incidence of fungus diseases will be lessened. The homeowner has a number of
pest resistant grass varieties and alternative low maintenance ground cover
plants to choose from and can avoid the intense management practices that are
often used to control pest damage on ornamental turf.
If pest problems identified by careful monitoring lead to deterioration of the
turf quality, renovation to promote healthy turf may be the wisest, most
economical choice for the long term application. Lesser problems may be solved
by use of chemicals on a short term or spot treatment basis with better cultural
practices as a followup.
All of the above statements are parts of an IPM program advocated by EPA's
Office of Pesticide Programs (OPP) through the IPM staff. Research papers on
state of the art technology for turfgrass IPM are being published by OPP this
spring. The IPM Unit is also developing a workshop to focus on IPM strategies
for pest problems on turfgrass in various parts of the country. The workshop
will be taught by regional experts who are doing research on turfgrass pest
A guidance document on a turfgrass IPM strategy for golf courses and home lawns
is planned for later this year. It is an outgrowth of discussions with golf
course superintendents, with the lawn care industry, and with citizen groups
concerned about the impact of lawn pesticide use on human health and the
environment through direct exposure and through potential contamination of water
resources. It can be used by local jurisdictions to evaluate IPM programs
proposed by developers as part of the requirements for obtaining building
permits for golf courses, and to develop IPM programs for maintenance of public
8. Should homeowners know more about pesticides use on lawns?
We support consumer awareness of pesticide use and encourage.homeowners to
obtain information on the pesticides which are used on their lawn. Homeowners
should be sure to read and follow the label carefully for any products they
apply themselves and should always ask to see the label of any products
commercial lawn care services used before these products are applied. EPA has
focused its efforts.on providing guidance to homeowners on whether and how to
choose pesticides or commercial application services through pamphlets like its
"Consumer's Guide to Safer Pesticide Use" and through development of turfgrass
IPM strategies and instructional materials. EPA also maintains a pesticide
hotline (1-800-858-7378) for homeowners who want additional information or who
may need emergency medical advice if a pesticide incident has occurred.
9. Isn't posting of lawns an important step to take?
Posting of lawns has been a controversial practice. EPA does not require
routine posting, but some states, (New York, for example) require commercial
applicators to post treated lawns. Any successful posting program needs to
address the following problems:
- Those most at risk, small children and pets, can't read.
- The signs are often so small and low to the ground that it's difficult to read
the message and still avoid contact with treated grass.
- If signs are left to weather and rot, they would lose any effect they may have
- Some lawn pesticides have a very low degree of toxicity. To require posting of
lawns treated with those pesticides may raise unwarranted alarm.
- No one sign is suitable for all pesticides, yet multiple signs pose a logistics
- Homeowners apply, on a percentage basis, far more pesticides than commercial
applicators but requiring them to post treated lawns has a number of practical
An alternate approach is to create a registry of those persons who want to be
notified before a neighboring area is treated. The commercial applicators then
notify these individuals whenever they are treating that area. Such ordinances
originate at the local or state level.
MAJOR LAWN PESTICIDES
1Chemical also has food or feed uses.
2Registration Standard has been issued.