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 

Science 

Cynthia 

Information 

Doucoure, Environmental 

and Analysis Branch 

Protection Specialist(] ~ 

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 

Timothy 

Economic 

Kiely, 

Analysis 

Chief 

Branch q~ \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 of this document is to convey usage information and a broad overview of the pest 

management roles of pesticides that are beginning to undergo registration review. The 

anticipated audience consists of the team of EPA staff currently evaluating the registration status 

of phosphine, 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 on information and data available to BEAD as of April2012. 

Aluminum phosphide was first registered in the 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 of the major chemical 

alternatives to methyl bromide, which has been phased out under the Montreal Protocol except 

for some special exemptions. 

While the complete mode of action of phosphine 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 of a building that is, or may be, 

occupied by humans and/or domestic animals. 

2 
USAGE 

Postharvest Use of Aluminum/Magnesium Phosphide and Phosphine in the U.S. 

Available data on the use of aluminum and magnesium phosphide and phosphine in agricultural 

and non-agricultural sectors in the U.S. are very scarce, with the exception of use trend data from 

California DPR. The best available data that are national in scope are both dated and limited in 

terms of years and crop or sector coverage. 

In Table 1 below, Kline & Company, a private market research company, reported use of these 

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% of the market. 

T a e bl 1 Ph ospJ hi ne an dAl ummuman dM agnes1um Ph ospJ h"d 1 e U seon St ore dG rams . 

Rate of Rate of 

Application to Application to 

Sector Year 

Sales by Pounds A.I. Grain Empty Bin 

(lb or gal/1 000 (lb or gal/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 USDA NASS, these results refer to pesticide applications 

and integrated pest management at off-farm storage and processing facilities after harvest. 

USDA NASS surveyed for use of magnesium phosphide and phosphine on these crops but did 

not have sufficient reports to publish usage data. 

Table 2. Postharvest Use of Phosphine and Aluminum and Magnesium Phosphide on Com, 

Oats, Peanuts, and Wheat 

Total Pounds Applied 

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 

3 
California: Use Trend of Phosphine and Aluminum and Magnesium Phosphide 

The best available state-level data on use of phosphine and aluminum and magnesium phosphide 

are from California's Department of Pesticide Regulation's Pesticide Use Reports, as shown in 

Table 3. While these data do not reflect national usage, they do show the relative importance of 

these chemicals in California's agricultural and non-agricultural market. 

Based on available data, it appears that use of these fumigants in recent years has been above 

average, particularly that of phosphine, whose use in 2009 increased by over 400% from that in 

2008. This increase is explained by two major factors, a new phosphine product was introduced 

that allows for better control and target fumigations and the reduction of availability of methyl 

bromide in this market because of the Montreal Protocol obligations . 

. Table 3. Agricultural and Non-agricultural Use of Phosphine and Aluminum and Magnesium 

Ph osp1 h.d 1 em · c a r£ 1 orma, · 2ooo -2oo9 

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 

4 
Figure 1. Pounds of Fumigants Used in California, 2000-2009 

"0 

Ql :a 200,000 +---------- --jf--

Q. 

< 

~ 150,000 +----1~--- r---flfC--.. 

"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 of Pesticide Use Report Data, 2009 

BIOLOGICAL ASPECTS RELEVANT TO PHOSPHINE 

Phosphine is considered to be a major chemical alternative to post-harvest uses of methyl 

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 if sealing is 

done properly, exposure periods are lengthened, higher dosages used, and temperature and 

humidity conditions are favorable . . 

Resistance of stored product pests to phosphine is documented in other countries, such as 

Australia, Brazil, China and India. However, a strain of phosphine-resistant grain insects has 

been eliminated by applying recommended management principles, including hygiene treatments 

and proper dosing of phosphine in gas-tight storage facility (GRDC 2011). This indicates that 

resistance to phosphine in stored product pests can be managed. 

HISTORY OF BEAD ASSESSMENTS FOR PHOSPHINE 

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). 

5 
INFORMATION THAT MAY BE USEFUL FOR BEAD'S FUTURE WORK ON 

PHOSPHINE 

Obtaining current information on the following items would improve future BEAD assessments 

of the importance of phosphine, and aluminum and magnesium phosphide on a national level and 

may be required as part of the registration review ofthis pesticide: 

• Indoor fumigation of raw agricultural commodities, animal feeds, processed food 

commodities, non-food commodities in sealed containers or structures, and outdoor 

fumigation of burrows 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 of methyl bromide. Memorandum to Debra Edwards. 

California DPR, Summary of Pesticide Use Report Data, 2009, 

http://www.cdpr .ca.gov/docs/pur/pur09rep/09sum.htm#fumigant 

Cook, C and M Ran ville. 2011. Assessment of impacts of a stay of food tolerances for sulfuryl 

fluoride on selected post-harvest commodities. U.S. Environmental Protection Agency. Docket: 

EPA-HQ-OPP-2005-0174-0111. 

FAO Manual of fumigation 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=54 7DE41 FF3245EC020EA436CO 

7 4C453C&pageN umber= 1 &filter 1 =&filter2=&filter3=&filter4= Accessed: April 9, 2012. 

IRAC. 2012. Mode of Action 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 PR Ebert. 2011. Mechanisms of 

phosphine toxicity. Journal of Toxicology 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 

6