	U. S. ENVIRONMENTAL PROTECTION AGENCY

	Washington, D.C. 20460	

       OFFICE OF 

	PREVENTION, PESTICIDES

	AND TOXIC SUBSTANCES 

Date: June 28, 2007

MEMORANDUM

SUBJECT:	Summary of the Discussion Between EFED and SRRD on the Exposure
and Potential Risk to Non-Target Organisms from Allethrins – June 28,
2007

TO:		Molly Clayton, Chemical Review Manager

		Kevin Costello, Team Leader

		Special Review and Reregistration Division (7508P)

 

FROM:	Melissa Panger, Ph.D., Biologist

		Environmental Risk Branch IV

		Environmental Fate and Effects Division (7507P)

 

Exposure and Risk to Non-listed Birds and Mammals

The potential for risk to non-listed terrestrial organisms is limited or
eliminated by the application methods described on the product labels. 
For instance, the use of Rainbow Wasp and Ant Spray is intended as a
spot treatment on wasp or other stinging insect hives.  The registrant
described the typical use of the spray as a 3-second directed
application at a hive, which would result in an application of about
0.156 g to an area of about 1000 cm2.  This rate is equivalent to an
application of about 13.8 lb ai/acre.

If this application rate is used as input to the T-REX model, the acute
and acute endangered species RQs for birds and mammals would exceed
levels-of-concern.  However, the exposure scenario is too unrealistic to
expect risk to birds and mammals.  To reach that level of exposure,
birds or mammals would essentially need to consume the treated hive to
ingest the allethrins applied by a directed spray.

The fogger application for the allethrins also represents an exposure
scenario that is unlikely to result in risk to non-listed birds and
mammals.  The risk assessment considered exposure from the Raid Yard
Guard Outdoor Fogger Formula VII, a total release fogger which could
affect flying insects in a 15-by-15 foot area, releasing 1.07 g of
allethrins along with another insecticide.  If all the mass of
allethrins were deposited in that 225 square-foot area, the application
would be equivalent to about 0.47 lb ai/acre, and the resulting RQs
would exceed the endangered species levels of concern for birds and
mammals.

However, that level of exposure to non-target birds and mammals is very
unlikely.  First, non-target animals would have to derive all of their
food from the 15-by-15 foot area in which a person just placed a fogger,
whether that area is a backyard patio or a lawn.  Presumably, the fogger
will have been placed in such an area so that people can be present,
which makes the likelihood of feeding less likely.  In addition, the
fogger application is designed to keep the applied insecticides in the
air, so that allethrins can work as a knockdown agent while the other
insecticide takes effect.  The applied material is unlikely to deposit
solely within the 15-by-15 foot area, but would be dispersed over a
wider area at a lower rate, dissipated by wind and degraded by
photolysis.

Acute Risk to Listed Fish and Invertebrates

As we discussed in our meeting on June 28, 2007, the indication of
possible acute risk to listed fish and aquatic invertebrates in Table 10
of the Environmental Fate and Ecological Risk Assessment for the
Reregistration of the Allethrins referred to indoor uses of allethrins,
which the registrant subsequently agreed not to support.  Acute risk to
listed aquatic animals is not indicated by our risk assessment for
remaining uses of the allethrins.  However, the potential for chronic
risk to listed aquatic animals cannot be precluded at this time due to a
lack of chronic toxicity data.

