UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D

.C

. 20460 

## AUG 

# 06 2DJ2

MEMORANDUM OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION



### SUBJECT: BEAD Chemical Profile for Registration Review Phosphine (066500), Aluminum Phosphide (066501) and Magnesium Phosphide (066504) 

### FROM:

THRU: Colwell Cook,

# Entomologist~ Biological Analysis Branch Cynthia Doucoure, Environmental Protection Specialist(]

## ~ Science Information and Analysis Branch Derek Berwald, Economist

## ~ (\+.

## \AA**~** Economic Analysis Branch 

### "-J

# J Biological and Economic Analysis Division (7503 Amet Jones, Chief Biological Analysis Branch Diann Sims, Chief Science Information and Analysis Branch

# q~ Timothy Kiely, Chief Economic Analysis Branch 

## \IV\, Biological and Economic Analysis Division (7503P) 

### TO: Dana Friedman, Chemical Review Manager Risk Management and Implementation Branch 2 Pesticide Re-evaluation Division (7508P)



### Product Review Panel date: May 05, 2012 INTRODUCTION The purpose ofthis document is to convey usage information and a broad overview ofthe pest management roles ofpesticides that are beginning to undergo registration review. The anticipated audience consists ofthe team ofEPA staffcurrently evaluating the registration status ofphosphine, aluminum phosphide, magnesium phosphide, and eventually the general public.This document builds upon the data already provided in the "Usage and Label Use Data Packages" that are also provided to Registration Review teams by BEAD. The document is based oninformation and data available to BEAD as ofApril2012. Aluminum phosphide was first registered inthe U.S. in 1958, followed by magnesium phosphide in 1979 and phosphine in 2002. The Reregistration Eligibility Decision (RED) for aluminum and magnesium phosphide was signed in December 1998. Aluminum phosphide and magnesium phosphide liberate phosphine gas and are therefore clustered with phosphine for registration review. Phosphine gas is colorless and is effective against stored-product insect pests and vertebrate pests, mainly rodents. Phosphine may be used as a space fumigation (under tarps, mills, food plants, warehouses); as a vehicle fumigation (railcars, trucks, vans, containers); as a commodity fumigation (raw agricultural, processed foods); as a grain fumigation (silos, farm storage, flat storage); and as a vessel or ship fumigation. Phosphine is one ofthe major chemical alternatives to methyl bromide, which has been phased outunder the Montreal Protocol except for some special exemptions. While the complete mode ofaction ofphosphine is unknown, it is listed by IRAC as a mitochondrial complex IV electron transport inhibitor. There is some evidence that phosphine exposure also decreases acetylcholine esterase activity as well as increasing oxidative stress in cells (Nath, et al. 2011). 

### COMMON FORMULATIONS AND APPLICATION METHODS Phosphine is formulated as a pressurized gas. Aluminum and magnesium phosphide are formulated as impregnated materials, pellets/tablets, and granules which release phosphine gas upon exposure to atmospheric moisture.



### USE SITES Agricultural Use Sites Phosphine is an insecticide/rodenticide labeled for use on numerous stored raw commodities (i.e. tress nuts, dried fruits, cereal grains), animal feed and feed ingredients, and processed foods (i.e. candy, bakery mixes, crackers, cheese, meat products). Non-Agricultural Uses Phosphine is also labeled for use on numerous non-food commodities and other non-food items. These include tobacco, cloth fibers, feathers, hair, wood and wood products, paper, tires, and beehives. In addition aluminum/magnesium phosphide pellets/tablets are used for rodent control, especially burrowing pests. Pellets or tablets are placed into the rodent burrows. However, these products may not be used in burrows that are within 100 feet ofa building that is, ormay be, occupied by humans and/or domestic animals.
2USAGE Postharvest Use ofAluminum/Magnesium Phosphide and Phosphine in the U.S. Available data onthe use ofaluminum and magnesiumphosphide and phosphine in agricultural and non-agricultural sectors in the U.S. are very scarce, with the exception ofuse trend data from CaliforniaDPR. The best available datathat are national in scope are both dated and limited in terms ofyears and crop or sector coverage. In Table 1below, Kline & Company, a private market research company, reported use ofthese fumigants on stored grains, including wheat, com, rice, and soybeans, and peanuts. According to Kline and Company, during the 2002-2003 time periods, aluminum phosphide was the leading active ingredient used on stored grains (wheat, com, rice, and soybeans) with 791,000 pounds sold, which was 43% ofthe market.

T bl 1 Ph hi

a e ospJ ne an dAl dM ummuman agnes1um Ph h"d U ospJ 1 e seon St dG

. ore rams Rate of Rate of Application to Application to Sector Year Sales by Pounds A.I. Grain EmptyBin (lb orgal/1000 (lb orgal/1000 bushels) bushels) On-Farm Off-Farm Low High Low High Aluminum Phosphide 2002-2003 66,000 725,000 0.26 1.190 0.130 0.400 Magnesium Phosphide and 2002-2003 <5,000 <19,000 Phosphine Gas Source: Klme & Company, 2004

Best available data compiled from the USDA NASS Postharvest Chemical Use Surveys are presented in Table 2. According to USDANASS, these results refer to pesticide applications and integrated pest management at off-farm storage and processing facilities after harvest. USDA NASS surveyed for use ofmagnesium phosphide and phosphine on these crops but did nothave sufficient reports to publish usage data

. Table 2. Postharvest Use ofPhosphine and Aluminum and Magnesium Phosphide on Com, Oats, Peanuts, and Wheat Total PoundsApplied Crop,Postharvest Year Aluminum Magnesium Phosphine l'hosphide Phosphide Com 2004-2005 19,900 Oats 2005-2006 400 Peanuts 2004-2005 3,900 Wheat 2000 115,400 2009 118,300 <50 Source: USDA NASS Postharvest Chemical Use Surveys, 2000, 2004-2006, and 2009 3California: Use Trend ofPhosphine and Aluminum and Magnesium Phosphide The best available state-level data on use ofphosphine and aluminum and magnesium phosphide are from California's Department ofPesticide Regulation's Pesticide Use Reports, as shown in Table 3. While these data do not reflect national usage, they do showthe relative importance of these chemicals in California's agricultural and non-agricultural market. Based on available data, it appears that use ofthese fumigants in recent years has been above average, particularly that ofphosphine, whose use in

### 2009 increased by over

### 400% from that in 

### 2008. This increase is explained by two major factors, a newphosphine product was introduced that allows for better control and target fumigations and the reduction ofavailability ofmethyl bromide in this market because ofthe Montreal Protocol obligations

.

.Table 3. Agricultural and Non-agricultural Use ofPhosphine and Aluminum and Magnesium Ph h.d · 

### c r£ · 2ooo 2oo9 osp1 1 em a 1 orma, 

# - Pounds A.L Applied Year Aluminum Magnesium Phosphine Total Phosphide Phosphide 2000 119,784 3,550 0 125,334 2001 99,856 2,492 44 104,393 2002 169,218 4,824 901 229,727 2003 119,512 2,844 1,141 125,500 2004 131,303 2,621 1,664 137,592 2005 135,751 3,156 2,688 263,092 2006 150,555 3,931 2,774 159,266 2007 104,840 4,984 5,262 117,093 2008 132,296 10,507 48,243 276,359 2009 156,241 7,957 263,667 429,874 Average 131,936 4,687 32,638



### .. Source: Cahfomta DPR, Summary ofPestlctde Use Report Data, 2009



### 4Figure 1. Pounds ofFumigants Used in California, 2000-2009

"0 Ql 

## :a 200,000 +--- ------- --jf-- Q. <**~** 150,000**+-- --1~** **--- r--** **-fl fC--..**  

### "' "0 § 100,000**-t- ~J.---** **---------' -+-**  0 a.

0 o rl N m**~ ~** **~ ~** **~** m 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 N N N N N N N N N N Year - Aluminum Phopshide

- Magnesium Phosphide

- Phosphine

Source: California DPR, Summary ofPesticide Use Report Data, 2009

BIOLOGICAL ASPECTS RELEVANT TO PHOSPHINE Phosphine is considered to be a major chemical alternative to post-harvest uses ofmethyl bromide, which was phased out in developed countries in 2005, except for special exemptions, under the Montreal Protocol. Like all fumigants, maximum control can be attained ifsealing is done properly, exposure periods are lengthened, higher dosages used, and temperature and humidity conditions are favorable

. 

# . Resistance ofstored productpests to phosphine is documented in other countries, such as Australia, Brazil, China and India. However, a strain ofphosphine-resistant grain insects has been eliminated by applying recommended management principles, including hygiene treatments and proper dosing ofphosphine in gas-tight storage facility (GRDC 2011)

. This indicates that resistance to phosphine in stored product pests can be managed.

HISTORY OF BEAD ASSESSMENTS FORPHOSPHINE No specific assessments for phosphine have been conducted by BEAD. However, phosphine has been included as the main alternative for impact analyses conducted for post-harvest uses of methyl bromide (Becker, et al. 2006) and sulfuryl fluoride (Cook and Ranville 2011).

5INFORMATION THAT MAY BE USEFUL FOR BEAD'S FUTURE WORK ON PHOSPHINE Obtaining current information on the following items would improve future BEAD assessments ofthe importance ofphosphine, and aluminum and magnesium phosphide on a national level and may be required as part ofthe registration review ofthis pesticide:
• Indoor fumigation ofraw agricultural commodities, animal feeds, processed food commodities, non-food commodities in sealed containers or structures, and outdoor fumigation ofburrows to control rodents and moles in non-domestic areas, non-cropland, and agricultural areas.

REFERENCES Becker, J, W Chism, C Cook, M Kaul, D Donaldson, E Rim, TJ Wyatt. 2006. Impact assessments for postharvest use ofmethyl bromide. Memorandum to DebraEdwards. California DPR, Summary ofPesticide Use Report Data, 2009, http://www.cdpr.ca.gov/docs/pur/pur09rep/09sum.htm#fumigant Cook, C and M Ran ville. 2011. Assessment ofimpacts ofa stay offood tolerances for sulfuryl fluoride on selected post-harvest commodities. U.S. Environmental Protection Agency. Docket: EPA-HQ-OPP-2005-0174-0111. FAO Manual offumigation for insect control- chemicals used as fumigants- phosphine. Found at: http://www.fao.org/docrep/x5042e/x5042EOa.htm

. Accessed April 9, 2012. Grains Research and Development Corporation (GRDC). 2011. Phosphine-resistant grain insects eliminated. Found at: http:/ /www.grdc.com.au/director/research/harvesting?item id=547DE41FF3245EC020EA436CO 7

4C453C&pageNumber=1 &filter1 =&filter2=&filter3=&filter4= Accessed: April 9, 2012. IRAC. 2012. Mode ofAction Classification. Available at: http://www.irac-online.org/wpcontent/uploads/MoA-classification.pdf

. Accessed April 9, 2012. Nath, NS, I Bhattacharya, AG Tuck, DI Schlipalius, and PREbert. 2011. Mechanisms of phosphine toxicity. Journal ofToxicology Volume 2011, Article ID 494168, 9 pages. Kline and Company, The U.S. Market for Stored Grain Insecticides, 2004 USDA NASS Postharvest Chemical Use Surveys, 2000, 2004-2006, and 2009



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