Summary of Comments Received on the Metaldehyde RED

and EPA Responses

June 13, 2007

The Agency received substantive comments on the Metaldehyde RED from
diverse sources, including a dog owner, registrants of metaldehyde
products and an alternative product, the San Francisco Department of the
Environment, the U.S. Department of Agriculture’s Animal and Plant
Health Inspection Service (APHIS), and a group representing California
Citrus Growers.

Many commenters submitted similar remarks, while some comments
conflicted with others.  Comments fell into nine general categories,
corresponding to the boldface headings below. 

The RED specifically solicited comments on how directions to exclude
children and domestic animals from residential areas treated with
metaldehyde could be enhanced via a graphic representation in product
labeling, and on the addition of  blue dye to all formulations to
discourage ingestion by wildlife and to make the product more visible
after application.  These two issues were addressed by many of the
commenters.

Labeling/precautions

Comments of several registrants of end-use metaldehyde products
included:  The precautionary text required by the RED for product labels
is excessive in length and contains redundancies, especially in text
relating to the exposures of children and pets.  More concise
precautionary language on the label would improve risk reduction. One
correspondent suggested that precautionary statements could be combined
to reduce the amount of text. 

A registrant of end-use metaldehyde products commented that the drift
statement is not applicable to granular products.

Two registrants commented that the statement, “[t]his product may be
fatal to children and dogs…if ingested,” (emphasis added) and its
variants in the precautionary and storage/disposal language of
metaldehyde products are not based on toxicity data or findings from
human incident data.  No human fatalities or life-threatening incidents
were associated with metaldehyde exposure in the years 1993-2003.  A
similar statement is not required for the anticoagulant rodenticides,
for which reports of human poisoning are more numerous and more serious.


A registrant commented that stand-alone text prohibiting broadcast,
foliar, turf, and dichondra applications is repeated in the directions
for use.   

A registrant commented that the label should caution about the
application of metaldehyde pellets in piles that might attract pets.

  

Agency response:  EPA crafted the precautionary language on the
residential product labels to emphasize key protections, but in view of
the number of comments on the redundancy and volume of precautionary
statements, we agree to some modifications to limit redundancies and
reduce the amount of text. 

The general application restrictions for residential products in dry
formulations are amended, in recognition that it is unlikely that
pellets and granular materials will drift.  

The data do not indicate that the exposure of children to metaldehyde
has resulted in lethal effects, but numerous nonlethal incidents have
been recorded.  EPA agrees to revise the label requirement to correct
the statement in question.

 

The prohibitions against broadcast, foliar, turf, and dichondra
applications are key risk mitigation measures and represent practices
that consumers may have relied upon in the past.  The statements will
still be required both as free-standing statements on product labels and
in the directions for use.

The Agency agrees to add text addressing the application of metaldehyde
pellets in piles. 

The San Francisco Department of the Environment commented that certain
elements of the residential product labeling should be presented in a
way that makes them more obvious.  Permitted uses and use patterns
should be presented in tabular form.  The 1-foot setback around plants
for which metaldehyde is not registered should be emphasized.

  

Agency response:  Registrants will be required to list the uses for
their products on all

labels.   Labels must also provide application rates, retreatment
intervals, numbers of applications, and any specialized instructions
relating to application method.  For residential products, application
rates must be given in user-friendly terms, e.g., “Apply one teaspoon
of pellets per linear foot around the plants to be protected.”  Since
many use sites share use parameters, a table may not be the most
efficient way to communicate the information.  In this instance, the
manner in which this information is presented is left to the discretion
of the registrant, but labels will be reviewed for compliance and
clarity.  

The Agency will require that the statement about the 1-foot setback,
since it is unusual, be printed on the labels of residential products
with fruit or vegetable uses in a manner which draws attention to the
change in use practices.



A registrant of an alternative snail bait commented that residential
product labels should indicate that “overuse may result in food
residues.” 

 Agency response:  Because any use of metaldehyde in residential
gardens--not just overuse--may result in residues in produce from these
gardens, this comment is not precisely correct.  Residues of metaldehyde
do appear in commodities from treated fields, and the Agency has
assessed the dietary exposures and risks associated with the use of
metaldehyde in commercial production of such commodities.  The current
assessment of dietary risks indicates that they are not of concern for
the general population or more highly exposed subpopulations.  The
Agency has not developed a method for assessing dietary exposures
associated with homegrown produce, but believes that the new application
rate limits and the 1-foot setback help preserve critical uses for
subsistence gardeners while limiting their dietary exposures.

                                                                        
                                                                        
                        

Conflicting comments were submitted on the graphic representation for
the exclusion of children and domestic animals from residential areas
treated with metaldehyde (e.g., a red circle with a diagonal line
through it, “Children and Pets” inside the circle).

A number of comments were made in opposition to the requirement for the
graphic.  These comments were made by registrants of metaldehyde
products:

Consumers might interpret the graphic to mean that they cannot not use
the product if they have children or dogs.  Written instructions should
be sufficient.  According to informal polling conducted by a metaldehyde
formulator, the graphic alone is confusing.  The use of symbols to
communicate such information must be supported by educational efforts. 
Requiring graphical warnings is premature because there are no standards
for their use on pesticide labels; data from the metaldehyde incident
monitoring program will assist in determining whether and what graphics
are useful.  Research indicates that a common warning symbol (i.e., Mr.
Yuk) is not effective in keeping children away from poisons.  

Several submitters commented in favor of the graphic.  These comments
were made by a dog owner whose pet was poisoned by metaldehyde
ingestion, a registrant of an alternative slug bait, and the San
Francisco Department of the Environment:

Eye-catching warnings such as the graphic discussed in the RED could
alert users and help to prevent pet poisonings (the commenter’s dog
was poisoned by metaldehyde applied to a residential area; the dog
recovered after expensive veterinary treatment).  The graphic will draw
attention to changes on the product labels.  Another submitter remarked
on his organization’s successful experience with large symbolic
warnings in communicating hazards to consumers, and noted that the
circle with a line through it is universally recognized, and most
effective if the image is clear and supported by text.

Agency response:  EPA believes that multiple approaches are needed to
inform users and reduce metaldehyde poisoning incidents in children and
pets--strengthening precautionary information on residential product
labels, placing restrictions on the use of these products in yards and
areas with the potential for similar exposures, and providing
specifications for how the materials may be formulated.  A key component
of the precautionary labeling is emphasizing the hazard to children and
pets.  Currently, most residential use products bear text warnings; in
order to improve risk communication, the Agency believes that
additional, uniform language and the graphic are needed.

The graphic is not intended to be a substitute for the language.  It
should draw the attention of the consumer to precautions that might
otherwise be overlooked, as it appears to be common that consumers do
not closely examine the labels of familiar products.  If there is a
question about the meaning of the graphic, the user can find written
precautions and instructions about pets and children in the text portion
of the label.

The Agency does not feel that the purported failure of the “Mr. Yuk”
graphic to prevent children from exposure to poisonous materials is
relevant in this case. Although some metaldehyde products will bear the
Mr. Yuk graphic in association with their incorporation of a particular
form of the bittering agent, the new graphic required on the metaldehyde
product labels is aimed not at children, but at the consumer and adult
user.  It is the Agency’s expectation that children and pets will be
prevented access to metaldehyde products by responsible, informed
adults.

The Agency solicited input on the type of graphic that should be used,
but no new ideas were brought forth.  The type of graphic discussed in
the RED is a familiar format used to convey prohibitions for smoking,
littering, and keeping pets away from certain areas (such as designated
areas of roadside rest stops).  While the Agency agrees that there is no
standard for the use of such symbols on pesticide labels, and believes
that refinements may be suggested by the incident monitoring data, the
use of graphic cues should complement new label text and other efforts
to reduce poisoning incidents.  The risk mitigation program for
metaldehyde is performance-based, so that if these new risk mitigation
measures aimed at reducing the number and severity of poisoning
incidents are not successful, more restrictions may be added in the
future.

The comment that the graphic should be augmented with a program of
educational outreach to the user suggests another opportunity for
registrants to improve the performance of the metaldehyde mitigation
program.  Such a program could include posters or brochures at the point
of sale, and registrants should consider posting information on their
company websites.  Website information would be especially useful for
people seeking quick answers on how to respond when a pet ingests
metaldehyde.  The Agency will discuss these suggestions with the
registrants. 

EPA will amend the RED to specify that the graphic discussed in the
original RED (i.e., a red circle with a diagonal line through it, the
words “Children and Pets” inside the circle) is the only acceptable
graphic at this time.

Blue dye/formulation changes

Comments on the blue dye varied and some were contradictory:

A metaldehyde registrant proposed that the use of colored pellets be
made optional.  Another metaldehyde registrant suggested that other
bright, non-natural colors may be effective in discouraging ingestion by
birds, especially if the visual cue is coupled with a taste-conditioned
aversion.

A registrant of an alternative snail bait cited data on the
effectiveness of blue dye in reducing ingestion by birds.  This same
commenter noted that in agricultural applications, the blue color would
help workers be precise in their placement of the pellets.  

 

Comments from the San Francisco Department of the Environment and
several registrants reflected a concern that blue or bright-colored
granules might look like candy or otherwise be attractive to toddlers
and children.  The San Francisco Department of the Environment and a
registrant of an alternative snail bait commented that blue dye could
make it easier for residential users to determine when pellets are no
longer visible, i.e., when pets and children can be allowed access to
previously treated areas, but the Department indicated that residential
users on the West Coast are likely to replenish metaldehyde bait
continuously during the time when slugs are a problem, so that they
would rely more on minimum retreatment intervals than a visual
assessment of the previous application. 

A metaldehyde registrant has found that growers express concern about
dye bleeding onto plant parts or about the visibility of blue pellets in
potted ornamentals. A registrant of an alternative snail bait has
experience with blue dyes that will not leach color even when baits are
soaked in water are available.

Agency response:  EPA has considered information supplied by commenters
on the attractiveness of blue pellets to children and on the avoidance
of blue pellets by birds in the field, and other information from the
open literature.

Based on this input, EPA believes that there is enough uncertainty about
the impact of color on children’s exposures to warrant reconsideration
of this requirement.  The Agency has also reconsidered this requirement
because the body of literature contains numerous studies with
conflicting results on the effectiveness of dyes in discouraging
ingestion of food pellets by wildlife. 

Without conclusive information of the effect of blue or other coloration
on ingestion by wildlife species, domestic animals, and children, EPA is
unable to confirm the utility of this approach.  EPA withdraws the
requirement that residential metaldehyde products be colored with blue
dye, but agricultural products may be colored at the discretion of the
formulator.

Comments on the use and testing of non-food inerts from different
sources were contradictory:

One registrant defines food-based inerts formulations as pellets, and
non-food-based inerts formulations as granules; the “pellets” are
effective for longer periods and the “granules” provide faster
knockdown but need to be applied more frequently. Granules are not
attractive to pets, so don’t need bittering agent.  Use of sand-core
formulations (granules) on turf and dichondra should be permitted.

Another registrant wrote that metaldehyde baits formulated without
food-grade components are ineffective, so the efficacy testing
requirement is not applicable.

Agency response:  EPA has no information on which to base a
determination about the attractiveness of domestic animals or wildlife
to sand-core granules of metaldehyde.  If the registrant wishes to
pursue having the bittering agent requirement lifted for sand-core
granules, data on the relative attractiveness of sand-based formulations
and food-based formulations to domestic animals or wildlife are
essential.

The submitted comments about sand-core formulations point to the need
for efficacy testing of metaldehyde formulations with and without
food-grade inerts.  These efficacy data currently are required to
support the registrations of metaldehyde products.  

Comments on bittering agents:  

A registrant of an alternative snail bait and the San Francisco
Department of the Environment support the use of a bittering agent and
the testing of bittering agents.  The alternative product registrant
suggested that if the bittering agent doesn’t reduce pet poisonings,
residential uses should be terminated.

A metaldehyde registrant wrote that the literature demonstrates the
effectiveness of the currently used bittering agent, that registrants
should be permitted to submit additional published studies, and that
requirements for testing bittering agents are unclear.  The same
registrant noted that dogs tend to gulp their food, so they can ingest
large quantities of material before they taste it, rendering bittering
agents ineffective.  Requiring rigid plastic (or other puncture- and
tear-resistant) packaging may be more effective than the use of
bittering agents.  

Agency response:  As noted above, if the implementation of mitigation
measures does not bring about a reduction in poisoning incidents, EPA
will consider additional restrictions on the metaldehyde registrations,
possibly including the termination of residential uses.

The registrants and the public at large were given a 60-day period after
release of the metaldehyde RED in which they were free to comment on the
decision and submit any information they thought would bear on that
decision.  No substantive information on the effectiveness of denatonium
benzoate was submitted during that time.  The Agency considered the open
and proprietary literature on the subject before determining that
empirical data were needed to show the efficacy of bittering agents in
preventing ingestion of snail baits by domestic animals. 

 

The Agency is working with the registrant of technical-grade metaldehyde
to develop a protocol for aversion testing of bittering agents for use
in metaldehyde formulations.  Unless and until an effective substitute
is identified, metaldehyde formulators will be required to continue with
the current practice of incorporating the specific bittering agent at
the current concentration.

EPA acknowledges that dogs in particular can eat very quickly, and may
not detect the bitterness of an aversion agent at all or until it is too
late.  Required testing will examine this issue.

While EPA will encourage formulators to market their products in
tear-resistant packaging, we believe that emphasis on storage of
metaldehyde products out of the reach of children and pets is a more
suitable approach to mitigating risks.

Metaldehyde/carbaryl combination products

The San Francisco Department of the Environment believes that a benefits
assessment for the metaldehyde/carbaryl combination products would show
minimal benefits especially with the new restrictions in place.  The
Department expressed doubt that labeling on these products will be
sufficient to prevent inappropriate use.  Metaldehyde and
metaldehyde/carbaryl combination products should be packaged
differently, fonts and graphics on labels should differ, and combination
product labels should prominently warn against using the product unless
both types of pests are present at unacceptable levels.

Agency response:  Information on alternatives to and benefits of
metaldehyde combination products are extremely limited, but some
registrants assert that they fill an important niche.  It is known that
the same pests targeted by these combination products can be controlled
with other pesticides applied separately.  EPA has reexamined the
requirements for formulation and labeling of the combination products
and agrees that certain elements must be emphasized to discourage
unnecessary use.   Labeling requirements will be revised to address this
issue.

Avian/aquatic hazard statements

A registrant claimed that metaldehyde applied as a spot treatment is not
likely to be present on impervious surfaces after residential
applications, so the labeling, “…[s]weep up or collect and remove
any product that lands on the driveway, sidewalk, or other hard surface
on which it is spilled” is not needed.

Agency response:  In the interest of reducing the volume of label text
and more closely targeting exposures of concern, the Agency will require
abbreviated text for avian hazard statement on residential product
labels.

A registrant commented that metaldehyde does not meet LC50 threshold for
aquatic hazard statement.  

Agency response:  According to 40 CFR §156.85(b)(2), if a pesticide
intended for outdoor use contains an active ingredient with a fish acute
LC50 of 1 ppm or less, the statement, ‘‘this pesticide is toxic to
fish’’ is required.  Since the fish LC50 for metaldehyde is 69 ppm,
this statement is not required.  However, according to 40 CFR
§158.85(a), where a hazard exists to non-target organisms, EPA may
require precautionary statements of the nature of the hazard and the
appropriate precautions to avoid potential accident, injury, or damage. 
Metaldehyde is a molluscicide, for which toxicity to nontarget mollusks
is likely.  The Agency will amend the metaldehyde RED to substitute the
statement, “This pesticide is toxic to fish and aquatic
invertebrates,” with a statement on the risks to mollusks in the
aquatic hazard statements for both agricultural and residential use
products.

Site-specific use parameters

The California Citrus Mutual wrote that California citrus growers rely
on applications of metaldehyde at 1 lb. ai/A per application, up to
eight applications per season, at intervals of seven days.

Agency response:  Residue data were developed for citrus based on a
single application rate of 1 lb ai/acre, for a total of 6 lbs ai/acre
per year, at a minimum retreatment interval of two weeks.  Tolerances
are established based on this treatment regimen.  In order for the
Agency to approve an increase in the number of applications per season
or a reduction in the retreatment interval, additional field trial data
would be needed to quantify residues treated under a different regimen. 
In addition, the Agency would have to consider the effect of changes on
the risks posed by the increased numbers of applications and shorter
retreatment interval.

Risk Quotients (RQs) associated with the use of metaldehyde in citrus
exceed acute risk Levels of Concern (LOCs) for small and medium-sized
birds and mammals and for endangered species of birds and mammals.  RQs
could only be calculated for one type of aquatic wildlife in an acute
exposure scenario, because toxicity data for longer exposures and other
types of animals are lacking.  Although the acute RQ for freshwater fish
does not exceed the acute LOC, the absence of data on other types of
aquatic wildlife at acute and chronic exposures makes risks to these
species uncertain.  Of particular concern are risks to non-target
mollusks, since metaldehyde is a molluscicide.  Because metaldehyde is a
molluscicide, it is reasonable to assume some level of risk to these
species.  Additional applications and shorter intervals between
applications would only increase risks to wildlife.  Although
alternative controls for snails and slugs in citrus do not predominate,
an integrated approach to pest management in which other chemical (e.g.,
iron phosphate or copper) and cultural options are used to supplement
treatments with metaldehyde provides an alternative to using larger
amounts of metaldehyde. 

One registrant had a number of comments on parameters for various use
sites:

Allow shorter retreatment intervals after rainfall.  Allow use on
strawberries grown as annuals.  Do not limit applications of metaldehyde
on artichokes grown as annuals to fewer applications than are permitted
for artichokes grown as perennials.  Allow three applications/season on
blueberries.  Allow six applications/season on grass grown for seed. 
Allow use on other seed crops not used in food or feed.  Allow use of
all formulations on commercial turf and sod farms.  Allow use on prickly
pear cactus.  

 

Agency response:  Risk quotients were calculated and tolerances
reassessed for specific treatment regimens.  The impact of changes to
the assessed regimen cannot be determined without new data to support
the use parameters. Shorter retreatment intervals would likely increase
risks and residues in associated commodities.

USDA Crop Profiles indicate that commercial production of strawberries
grown as annuals is very limited, and that snails and slugs in
strawberries and artichokes grown as annuals do not have the opportunity
to reach populations as high as those in the corresponding crops grown
as perennials.  An academic expert has advised the Agency that in annual
strawberries, metaldehyde is not needed because snails and slugs do not
have a chance to build-up to damaging populations (personal
communication, Phil Phillips at UC Davis). 

An expert with the Artichoke Research Association at the USDA research
facility in Salinas, CA has advised us that currently, less than half of
the acreage of artichokes in California is in annual production (grown
from seeds or transplants), but that annual artichokes are on the
increase mainly because pest pressure (insects, mollusks, and weeds) is
significantly lower than in perennial production (personal
communication, Dr. Mohammad Bari, Entomologist).  Accordingly, this
expert further advised that no more than two applications per season of
metaldehyde would be needed for slug control in artichokes grown as
annuals, and that additional control can be achieved with applications
of iron phosphate.

EPA has been advised by an expert in the field that three
applications/season may be needed for blueberries in years of high
rainfall and high pest pressure (personal communication, Dr. Joe
DeFrancesco, IPM Center, Oregon State University on behalf of the Oregon
Blueberry Commission).  Labeling will be amended to reflect a maximum of
three applications/season on blueberries.  The prescribed maximum number
of applications for blueberries represents a reduction from the five
applications/season originally proposed by the registrants, resulting in
a reduction in the presumed ecological risk for the use on blueberries.

Risks from the use of metaldehyde on grass grown for seed were assessed
at 1.6 lb ai/A/application, a maximum of four applications per season,
and a minimum retreatment interval of 21 days.  The ecological Risk
Quotients associated with this treatment regimen are higher than those
discussed for the use on citrus.  In addition, metaldehyde is broadcast
applied in grass grown for seed, which may make it more available for
ingestion by terrestrial wildlife or for the contamination of aquatic
habitat.  EPA’s decision to prescribe a single maximum application
rate of 0.8 lb ai/A is based on the consideration of the high risk
associated with this use and information from experts.  The Agency was
advised that grass grown for seed may be treated with metaldehyde twice
in the Fall just as the rains begin and again twice in the Spring, and
that an individual application rate of 0.8 lb. ai is adequate (personal
communication, Dr. DeFrancesco).

Slugs and snails have become more of a problem as grass seed growers
adopted no-till planting, because dead and decaying plant material left
on the soil surface provides a ready hiding place for the pests.  EPA
has received anecdotal information suggesting that metaldehyde is the
most effective chemical control available, but that it does not
completely protect against economic loss from snails and slugs in grass
grown for seed.  It has been postulated that slugs, which may be found
at depths of ten feet or more beneath the grass fields, can effectively
avoid metaldehyde pellets on the soil surface.  Rather than allow more
metaldehyde to be applied to these fields, EPA believes that other
solutions should be employed that are less risky.

The use of metaldehyde on other crops grown for seed and on sod farms
has not been assessed, so an informed risk-benefit decision cannot be
made at this time.  It is not clear what commercial turf uses the
commenter is referring to, but decisions have been made to place
restrictions on the use of metaldehyde turf in parks, school yards, and
playing fields, because these sites are similar to residential turf in
the opportunities they afford for exposure to children, dogs, and
wildlife.

The use of metaldehyde on prickly pear cactus is a new use, and a
decision on its registration will be made outside the reregistration
process.

The manufacturer of technical-grade metaldehyde supports, and the Agency
has approved, the limits on application rates for ornamentals.  Risks
for this use are still high, and the Agency is requiring risk mitigation
measures targeted to reduce exposures to wildlife and domestic animals.

One registrant noted that broadcast applications are needed for grass
grown for seed.  Another registrant believes that allowable application
methods for agricultural crops should be listed on the product label.

Agency response:  The ecological risk assessment for grass grown for
seed is based on the broadcast application of metaldehyde.  Spot or
barrier treatments are not expected to be effective for this densely
planted crop, and the excess ecological risks are mitigated primarily by
reducing the number of applications in a season by half. Broadcast
applications to grass grown for seed will be permitted.  As noted
previously, labeling requirements for use parameters on all crops will
be amended to require additional information on application methods.

One registrant wrote that broadcast applications reduce potential for
wildlife and domestic animal poisonings.  Labels should allow broadcast
applications, particularly applications to ornamentals in commercial
production at 10 lbs ai/A/year for ornamentals, at up to 26
applications/year.  Labels should prohibit application to edible plant
parts, and prescribe banding or directed broadcast applications after
formation of edible crop parts.

Agency response:  In absence of data supporting the claim that broadcast
applications reduce the potential for animal poisoning, EPA maintains
that most metaldehyde applications must be limited to spot treatments or
barriers.  Labels will continue to prohibit applications of metaldehyde
to plant parts.

A registrant commented that APHIS/Plant Protection and Quarantine
maintains zero tolerance for slugs and snails on live plants in
interstate commerce.

Agency response:  Plant Protection and Quarantine requires permits for
the transit and domestic movement of plant pests including some snails,
and some State Departments of Agriculture (e.g., Hawaii and Oregon) also
have taken measures to prevent the domestic transport of particular
snails, including species which typically cause plant damage.  The
Agency recognizes that it is necessary to curb the interstate transport
of these pests on nursery stock, but does not feel that the restrictions
imposed on metaldehyde in ornamentals production need stand in
contradiction to that goal.  In fact, some large ornamentals producers
have reported that they prefer alternatives to metaldehyde, including
iron phosphate.  According to these growers, iron phosphate does not
leave visible and toxic residues in container plants, and the material
does not mold in the humid nursery environments and stick to
customers’ shoes.  The Oregon Department of Agriculture, in its
administrative directives for nurseries where the European Brown Garden
Snail has been found, orders that a combination of methods, including
pesticides and sanitation, be used to eradicate the snails before the
nursery can ship plants without visual inspection of the plant
materials.  The Agency encourages growers to use a variety of tools,
including cultural methods, in order to keep snails and slugs out of
their shipments of ornamentals.

Cultural practices

Comments from the San Francisco Department of the Environment express
the belief that listing cultural practices on metaldehyde product labels
is an interesting idea but unlikely to be effective.  A registrant
commented that the incorporation of this information on product labels
should be at the discretion of the registrant, and that a more general,
less detailed label statement on cultural controls, such as “contact a
garden professional for advice on how cultural practices can reduced
damage from snails and slugs,” is preferred.  Several registrants
believe that cultural practices fall outside of mitigation associated
with safe handling and use of the products and should not be required on
label.  One registrant wants EPA to encourage registrants to develop
outreach materials to augment the cultural practices information on the
product labels.

Agency response:  The Agency has formulated its labeling strategy to
promote the use of metaldehyde products according to the new information
on the label.  Consumers who make note of the new restrictions and
information about cultural practices may use that information to reduce
the exposure potential in their own yards.

The Agency believes that a requirement to incorporate information about
cultural controls on product labels is more equitable than allowing
registrants to choose whether or not to include such information on
their labels.  

In response to concerns that residential product labeling is excessive
in length, the Agency has reconsidered the labeling requirements for
cultural controls.  Rather than the more general statement suggested by
the comment, the Agency will abbreviate the statement from the RED that
gives specific examples of easy-to-implement cultural practices.

  

EPA does not agree that these measures fall outside of the scope of risk
mitigation for metaldehyde, since they do indeed advise users on how to
reduce exposures to metaldehyde.

Information on how to reduce exposures to metaldehyde may be made more
effective when supplemented with outreach efforts.  Outreach can include
materials developed by the registrants to be read at the time of sale,
contact with Cooperative Extension agents, or the placement of detailed
information on cultural aspects of slug/snail control on company
websites.  An educational effort of this nature should enhance the
registrants’ efforts to reduce incidents and the performance of the
mitigation plan overall.  We will discuss options in public outreach
with the registrants of metaldehyde products.

Invasive pests

USDA/APHIS notes that broadcast applications of metaldehyde products are
needed to support the critical use in Federal and State programs that
targets exotic, invasive snails and slugs.  These pests pose hazards to
humans as vectors of disease and to plants.

The maximum individual application rate used in the mollusk eradication
programs is 2 lb ai/A, with up to six treatments needed in a year.  A
Special Use Box on product labels could allow the use on particular
target areas by contractors or other personnel under APHIS direction.

Agency response:  The Agency has worked with APHIS to develop a Special
Use Box for the labels of metaldehyde products used by contractors to
APHIS or APHIS personnel in the mollusk eradication program. 
Application parameters will be specified on the labels.

Poison hotline

One registrant believes that the human and domestic animal statements
should be combined; listing one hotline phone number for human exposures
and one for domestic animal exposures is confusing to users and
inconsistent with goals of a common reporting system.  Another
registrant believes that incidents already are adequately reported under
6(a)(2).  Another registrant commented that the RED does not explain why
the NPIC hotline number is required on the label, and says the Agency
should not mandate this one service.

Agency response:  The Agency is revising the labeling requirements in
the RED to address the use of separate statements pertaining to humans
and domestic animals.

As noted in the RED, EPA is requiring the incident monitoring program
because neither 6(a)(2) reporting, nor reports to NPIC were successful
in capturing the large number of domestic animal incidents recorded by
the American Society for Prevention of Cruelty to Pets Animal Poison
Control Center, suggesting that poisoning incidents were underreported
by the two methods. 

The Agency has determined that its objectives for metaldehyde can be
satisfied without specifying a particular hotline service.  Rather, the
Agency believes that the use of hotline services that follow a
standardized call-answering and data collection protocol can adequately
address those objectives.

General Comments/Anecdotal Comments/Corrections

A dog owner whose dog was poisoned by ingesting a metaldehyde product
stated that residential products should be removed from shelves; they
can be fatal to animals and children, who frequently spend time in yards
that may be treated.  Metaldehyde products should only be sold under
controlled conditions.  The performance-based approach to residential
risk mitigation (with the possibility of greater controls if results are
not sufficient) is reasonable.  The commenter’s veterinarian told her
he treated five cases of metaldehyde poisoning in one recent weekend. 
Commenter’s own dog was lucky to survive a poisoning incident but
treatment was expensive.

Agency response:  EPA believes enhanced precautions will decrease
residential exposures.  The registrant of technical-grade metaldehyde
has committed to expedite aversion testing and the development of a
uniform and comprehensive domestic animal incident reporting system, and
will provide quarterly results from the reporting system.  The Agency
will evaluate confirmatory data from these efforts to determine what
effect label precautions, directions for use, and aversion agents have
on poisoning incidents among domestic animals.  The review of human
incident data will continue.  It may be several years before the new
mitigation measures produce results as consumers respond to new
restrictions for metaldehyde products, but formulators will continue to
incorporate the current bittering agent in all residential metaldehyde
products until such time as the Agency approves another agent.  If an
agent cannot be found which effectively prevents ingestion by dogs in
laboratory tests, the Agency may require additional mitigation, possibly
including the termination of residential uses, and testing of additional
aversion agents.

The San Francisco Department of the Environment supports the data
call-in of ecotoxicity data, but noted that without these data, the
impact of mitigation on aquatic wildlife is unknown.

Agency response:  The Agency will review the ecotoxicity data required
by the Generic DCI, and they will be considered in the development of
future decisions on metaldehyde—for the registration of new uses,
during Registration Review, and in implementing the Endangered Species
program.  The ecological risk assessments conducted for these decisions
will be modeled using parameters associated with relevant risk
mitigation measures imposed by the RED. 

A registrant of an alternative snail bait commented that label phrases
such as “ideal for vegetable gardens” and “can be used around
fruit and vegetable plants, lawns and ornamental plants too!” are
misleading and  imply a broader range of allowed uses.

Agency response:  The Agency will review all metaldehyde label
submissions for inappropriate or misleading statements, and will reject
any labels bearing such statements.  Registrants should take care to
assure that any nonprescribed language on product labels makes only
legitimate claims consistent with the terms of reregistration.

A registrant commented that the RED does not distinguish between
formulation types and the requirements for each.  

Agency response:  EPA has reviewed the RED and the label table and has
found only one instance in which the language that does not
appropriately account for the different formulation types.   To address
this comment, the drift statement for residential use products will be
revised.

  

A registrant wrote that few incidents are associated with true and
viscous liquid formulations, so they do not need same restrictions as
solid materials.

Agency response:  Incident data on the true and viscous liquid
formulations are not abundant enough for the Agency to conclude that
these formulations pose a lesser risk, even if it would seem so
intuitively.  In absence of compelling support to the contrary, the
Agency reconfirms that these materials must be amended with the
bittering agent.    

A registrant commented that carabid beetles are snail and slug
predators, and that there is no evidence of metaldehyde toxicity to
carabid beetles.

Agency response:  Several metaldehyde toxicity studies on the carabid
beetle were discussed and used in a qualitative manner in the ecological
risk assessment supporting the RED.  The RED itself states, “…toxic
effects …have also been observed in the carabid beetle.” Appendix D
to the Ecological Risk Assessment for Metaldehyde (available on the
public docket) lists the relevant scientific references.

A registrant noted that discussion of treatment costs does not account
for different application rates of metaldehyde and iron phosphate, which
is applied at a greater rate.

Agency response:  The Agency has more thoroughly explored the issue of
the relative costs of metaldehyde and iron phosphate based on maximum
and typical application rates.  The Agency has found that cost
differentials for agricultural uses are not significant.  For
residential applications, at maximum application rates, using iron
phosphate is more expensive than using metaldehyde.  The RED is amended
to reflect the more refined analysis of comparative costs.

A registrant commented that exposures of domestic animals to metaldehyde
other than by ingestion are not known to be lethal.

Agency response:  While EPA believes that inhalation and dermal
exposures to metaldehyde are possible among domestic animals,
documentation on the effects of these exposures is not available.  The
RED will be amended accordingly.

DeSangosse should be included in list of companies holding end-use
registrations.

Agency response:  EPA acknowledges DeSangosse’s metaldehyde
registrations.  The list of registrants the commenter refers to is
representative, not exhaustive.  

A registrant submitted the comment that residential use sites should not
include athletic fields, playgrounds, parks, and recreation areas. 
Affected use sites should be clearly defined.

Agency response:  The commenter is correct that athletic fields, etc.,
strictly speaking, are not residential sites, even though exposure
potential at these sites may be similar to that at residential sites. 
The RED will be revised to distinguish between residential use sites and
the other sites currently listed with them in the labeling requirements.
 

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