UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460      

	OFFICE OF PREVENTION, PESTICIDE

	AND TOXIC SUBSTANCES

	

  SEQ CHAPTER \h \r 1 MEMORANDUM

Date:  April 2, 2008

SUBJECT:	Ingredient:  Pyridalyl         Title:  Addendum to PP#s 2F6459
& 3E6592.  Pyridalyl in/on Cotton, Fruiting Vegetables, Leafy
Vegetables, Head & Stem Brassica Vegetables, Brassica Leafy Greens, and
Turnip Greens, Shrubs, Ornamentals and Non-bearing Trees.  Health
Effects Division (HED) Risk Assessment.

PC Code:  295149	DP Barcode: D351059

MRID No.:  None	Registration No.: None

Petition No.: None	Regulatory Action: None

Assessment Type: None	Reregistration Case No.: None

TXR No.: 0054837	CAS No.: None



	          	

FROM:	Lisa Austin, Ph.D., Toxicologist  SEQ CHAPTER \h \r 1 

		Registration Action Branch 1

		Health Effects Division (7509P)

THROUGH:	Dana Vogel, Branch Chief

		Registration Action Branch 1

		Health Effects Division (7509P)

		Pv Shah, Ph.D., Acting Branch Chief

		Inerts

		Registration Branch (7510P)

TO:		Olga Odiott  SEQ CHAPTER \h \r 1   SEQ CHAPTER \h \r 1 

		Insecticide Branch 

		Registration Division (7505P)

I.	 CONCLUSIONS

This memo serves as an update to the previous risk assessment of
pyridalyl (Memo, M. Clock-Rust, 8/26/04, D301446).  The previous risk
assessment conditionally required a 28-day inhalation toxicity study. 
HED has reconsidered this requirement and is now granting a waiver for a
28 day inhalation toxicity study for the proposed uses because pyridalyl
is in toxicity category IV via the inhalation route, has a low vapor
pressure (not likely to be volatilized significantly) and the calculated
inhalation MOEs range from 782-82,000.

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