UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C.  20460

OFFICE OF           

PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES

February 7, 2007

MEMORANDUM

SUBJECT:	Maleic Hydrazide (Chemical No. 051501).  Addendum to RED
Residue Chemistry Chapter: Recommendation for Tolerances in Meat, Milk,
Poultry, and Eggs (GLN 860.1480).  DP Barcode D330764. Reregistration
Case No. 0381.  MRID No. None.

FROM:	Thurston G. Morton, Chemist

Reregistration Branch 4

Health Effects Division (7509P)

THROUGH:	Susan V. Hummel, Branch Senior Scientist

Reregistration Branch 4

Health Effects Division (7509P)

TO:		John Pates

Reregistration Review Branch 1

Special Review & Reregistration Division (7508P)

EXECUTIVE SUMMARY:

This memorandum is an addendum to the RED Residue Chemistry Chapter and
serves to recommend tolerances for residues of maleic hydrazide (free
and conjugated) and 3-pyridazinone in the following livestock
commodities :

Cattle, meat ……………….....0.30 ppm

Cattle, meat byproducts……….4.0 ppm

          	Cattle, fat……………..……...0.40 ppm

	Milk……………….………….0.30 ppm

	Goat, meat……………………0.30 ppm

	Goat, meat byproducts…..…….4.0 ppm

	Goat, fat………………………0.40 ppm

DISCUSSION:

It has been determined tolerances are needed for residues of  maleic
hydrazide (free and conjugated) and 3-pyridazinone in cattle (meat, meat
byproducts, fat, and milk) and goat (meat, meat byproducts, and fat). 
These tolerances need to be inserted in 40 CFR §180.175(a)(1).  The
Agency is using the 28-day cattle nature of the residue study to
determine the appropriate tolerances.   The only feedstuffs are
processed potato waste and potato culls.  A reassessed tolerance of 50
ppm is recommended for processed potato waste.  No tolerances are being
recommended for poultry since processed potato waste is not fed to
poultry.  If in the future other uses on crops are requested with
livestock feedstuffs, then livestock feeding studies will be required. 
Dietary burdens for dairy and beef cattle are calculated below.

Calculation of Dietary Burden for Cattle.

Feed Commodity	Reassessed Tolerance (ppm)	% Dry Matter 1	Beef Cattle
Dairy Cattle



	% of Diet2	Burden (ppm)3	% of Diet2	Burden (ppm)3

Processed potato waste4	50	15	30	100	10	33

Soybean meal	NA	92	15	0	10	0

Field corn grain	NA	88	35	0	35	0

Field corn forage	NA	40	20	0	45	0

TOTAL	100	100	100	33

1As per Table 1 (OPPTS Guideline 860.1000).

2All beef and dairy cattle in the U.S. should have in their diet about
15% cottonseed meal, peanut meal, soybean meal, canola meal, or flax
seed meal.

3Burden = [tolerance ÷ % DM] X  % diet.

4Processed potato waste is a carbohydrate concentrate.  Feedlot cattle
may receive up to 50% of their diet as processed potato waste, however,
this would be in localized areas such as Washington, Idaho, and Oregon.

Reference: Table 1 Feedstuffs (October 2006)

cc: Chem F, Chron F. Morton 

RDI:Team: 2/7/07; SVH:2/7/07

TM, Thurston Morton, Cubicle s-10922, 305-6691, mail code 7509P

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