METHYL BROMIDE CRITICAL USE RENOMINATION FOR POSTHARVEST -- COMMODITIES

NOMINATING PARTY: The United States of America

FILE NAME: USA CUN12 POST HAVEST USE FOR COMMODITIES

BRIEF DESCRIPTIVE TITLE OF NOMINATION: 

Methyl Bromide Critical Use Nomination for Post Harvest Use on Commodities (Submitted in 

2010 for 2012 Use Season) 

QUANTITY OF METHYL BROMIDE REQUESTED IN EACH YEAR OF 

NOMINATION: 

TABLE 1: QUANTITY OF METHYL BROMIDE REQUESTED IN EACH YEAR OF NOMINATION

YEAR NOMINATION AMOUNT (KILOGRAMS) 

2012 4,907 

(Details on this page are requested under Decision Ex. I/4(7), for posting on the Ozone Secretariat website under 

Decision Ex. I/4(8).) 

In assessing nominations submitted in this format, TEAP and MBTOC will also refer to the original nomination on 

which the Party’s first-year exemption was approved, as well as any supplementary information provided by the 

Party in relation to that original nomination. As this earlier information is retained by MBTOC, a Party need not 

re-submit that earlier information. 

NOMINATING PARTY CONTACT DETAILS: 

Contact Person: John Thompson 

Title: Division Director 

Address: Office of Environmental Policy 

 U.S. Department of State 

 2201 C Street, N.W. Room 2657 

 Washington, D.C. 20520 

 U.S.A. 

Telephone: (202) 647-9799 

Fax: (202) 647-5947 

E-mail: Thompsonje2@state.gov

 

Following the requirements of Decision IX/6 paragraph (a)(1) The United States of America has determined that the 

specific use detailed in this Critical Use Nomination is critical because the lack of availability of methyl bromide for 

this use would result in a significant market disruption. ■ Yes  No 

 

Signature Name Date 

Title: 

USA CUN12 POST HARVEST COMMODITIES 1
CONTACT OR EXPERT(S) FOR FURTHER TECHNICAL DETAILS: 

Contact/Expert Person: Jack Housenger 

Title: Division Director 

Address: Biological and Economic Analysis Division 

 Office of Pesticide Programs 

 U.S. Environmental Protection Agency 

 1200 Pennsylvania Avenue, N.W. Mailcode 7503P 

 Washington, D.C. 20460 

 U.S.A. 

Telephone: (703) 308-8200 

Fax: (703) 308-7042 

E-mail: Housenger.Jack@epa.gov 

 

LIST OF DOCUMENTS SENT TO THE OZONE SECRETARIAT IN OFFICIAL NOMINATION PACKAGE: 

1. PAPER DOCUMENTS: 

Title of paper documents and appendices 

No. of pages Date sent to Ozone 

Secretariat 

USA CUN12 POST HARVEST: COMMODITIES 

2. ELECTRONIC COPIES OF ALL PAPER DOCUMENTS: 

*Title of each electronic file (for naming convention see notes above) 

No. of 

kilobytes 

Date sent to Ozone 

Secretariat 

USA CUN12 POST HARVEST: COMMODITIES 

* Identical to paper documents 

USA CUN12 POST HARVEST COMMODITIES 2
METHYL BROMIDE CRITICAL USE RENOMINATION FOR POSTHARVEST -- COMMODITIES

1. SUMMARY OF NEED FOR METHYL BROMIDE 

Commodity fumigation with methyl bromide is used primarily at harvest time, when rapid 

fumigation is needed to keep up with the large volumes of incoming commodities. Methyl 

bromide is also used in situations requiring rapid fumigation prior to shipping. 

TABLE 2. NOMINATION AMOUNT 

 California Dried 

Plum Board 

California Walnut 

Commission 

 California Date 

Commission 

 Sector Total / 

Average 

Quantity Requested for 2011: Amount (kgs) 1,170 6,266 2,009 9,445 

Quantity Recommended by 

MBTOC/TEAP for 2011 : Amount (kgs) 620 3,317 1,063 5,000 

Amount (kgs) 620 3,317 1,063 5,000 

Volume (1000 m3) 130 392 97 619 

Rate 5 8 11 8 

Transition from 2011 Baseline 

Adjusted Value Percentage (%) 0% 15% 0% -2%

Amount (kgs) 527 3,317 1,063 4,907 

Volume (1000 m3) 138 12 51 201

Rate 45 24 21 24 

Quantity Required for 

2012 Nomination:

Quantity Approved by Parties for 

2011:

SECTOR

COMMODITIES

2. SUMMARIZE WHY KEY ALTERNATIVES ARE NOT FEASIBLE 

This sector includes walnut, dried fruit (prunes, raisins, figs), and dates, all of which are subject 

to infestation by several insect pests. Since infestation begins in the field, methyl bromide is 

used to rapidly fumigate harvested commodities on arrival at processing plants on a daily basis. 

Most fumigation occurs over several weeks, during the peak production season, as the bulk of 

the harvest moves from the field into storage and shipping channels. Upon arrival from the field, 

each load is fumigated with methyl bromide in preparation for shipment to national and 

international markets. Any one load of commodities is fumigated with methyl bromide only 

once. 

Research with sulfuryl fluoride (SF) indicates that this fumigant is a potential methyl bromide 

alternative for walnuts, provided fumigation occurs at temperatures above 70 oF. Recent studies 

have shown that under vacuum or atmospheric conditions, SF is effective against adult, pupal, 

and larval stages of insects infesting walnuts. The ovicidal efficacy of SF, however, exhibits a 

marked temperature dependence, making it less effective against the egg stages of at least four 

insect pests of dried fruit and nuts, at maximum label rates and temperatures below 70 oF. 

USA CUN12 POST HARVEST COMMODITIES 3
Walnuts - Preliminary tests show that sulfuryl fluoride fumigation is comparable to methyl 

bromide fumigation in its ability to kill diapausing larvae of codling moth, Cydia pomonella, 

inside walnuts. While codling moth eggs are somewhat more tolerant than larvae to sulfuryl 

fluoride fumigation, they do not occur naturally on walnuts at the time of harvest. The navel 

orangeworm, Amyelois transitella, is primarily a scavenger, but will also infest walnuts after hull 

split, especially in areas that support high orangeworm populations. Occasionally, larvae 

emerging from eggs laid directly on walnuts shortly before harvest may penetrate and infest the 

nutmeat through cracks in the hull. Although insect eggs are relatively more tolerant of 

fumigants than other life stages, sulfuryl fluoride fumigation is lethal to three-day navel 

orangeworm eggs when used at the rate of approximately 56.5 mg/L (3.5 lb/1,000 cubic feet) for 

24 hours, at normal atmospheric pressure. 

The applicants indicate that USDA/ARS in Parlier, California has shown that SF does not readily 

kill egg stages of navel orangeworm or the eggs of several stored product insects at temperatures 

below 70 °F at or below maximum label rates. The applicants further observe that the walnut 

industry fumigates during 6 months of the year at or below 50 °F and provide supporting 

temperature data for the San Joaquin and Sacramento Valleys of California. The applicants 

believe that further research is needed on the ovicidal efficacy of SF at temperatures below 70 

°F, as well as on the ovicidal efficacy of propylene oxide/SF combinations. 

Dates - Methyl bromide is used primarily to control the carob moth and other insects infesting 

dates. Sulfuryl fluoride is currently labeled for use on dried dates, but most dates grown in the 

California are harvested fresh. The California Date Commission reports that it is currently 

testing the efficacy of sulfuryl fluoride on dates, with preliminary results showing less than 

adequate egg kill, even when the amount used is twice that needed for a comparable methyl 

bromide fumigation. 

Dried Fruit – SF is currently labeled for use on dried fruit for control of several insects. 

However, recent USDA research results presented at the 2009 MBAO meeting, indicate that 

under low temperatures and current label rates the ovicidal efficacy of SF is inadequate against 

several dried fruit pests. 

The potential use of sulfuryl fluoride for commodity fumigation is unrelated to the use of this 

chemical for structure fumigation. In the fist case, it is the commodities themselves that are 

fumigated, only once, and just before being shipped to their intended markets. In the second, it 

is a storage or food processing facility (i.e. a building) that is fumigated periodically, as needed 

3. SUMMARY OF RECENT RESEARCH 

Sulfuryl fluoride

Walnuts

Quick turn-around time for walnuts at harvest time is the primary justification for methyl 

bromide use in this sector. Vacuum fumigation with methyl bromide may take 4-6 hours and 

atmospheric fumigation approximately 24 hours. The methyl bromide use rate for this sector is 3 

USA CUN12 POST HARVEST COMMODITIES 4
lb/1,000 cubic feet. Phosphine gas fumigation takes approximately three days and is being used 

to fumigate walnuts in storage. 

Sulfuryl fluoride has been shown to be effective against the adult, pupal, and larval stages of 

several insect pests of stored products, although somewhat less effective against the egg stage 

(Fields and White, 2002, Schneider et al., 2003). Preliminary tests show that sulfuryl fluoride 

fumigation is comparable to methyl bromide fumigation in its ability to kill diapausing larvae of 

codling moth, Cydia pomonella, inside walnuts (Leesch, undated). Methyl bromide fumigation 

of in-shell walnuts has targeted primarily diapausing codling moth larva because this is the most 

tolerant life stage that may infest the nut at harvest. Data recently submitted to EPA by Dow 

AgroSciences (Muhareb and Hartsell, undated) indicate that vacuum fumigation with sulfuryl 

fluoride for four hours is effective against diapausing codling moth larvae at rates of 25 mg/L 

(1.5 lb/1,000 cubic feet), at 15.6oC (60.1oF) and 17-20 mg/L (1.06 - 1.25 lb/1,000 cubic feet), at 

25oC (77.0oF). While codling moth eggs are somewhat more tolerant than larvae to sulfuryl 

fluoride fumigation, they do not occur naturally on walnuts at the time of harvest (Wood, 1999; 

Zettler and Leesch, 2000; Zettler and Gill, undated). 

The navel orangeworm, Amyelois transitella, is primarily a scavenger, but will also infest 

walnuts after hull split, especially in areas that support high orangeworm populations. 

Occasionally, larvae emerging from eggs laid directly on walnuts shortly before harvest may 

penetrate and infest the nutmeat through cracks in the hull. Although insect eggs are relatively 

more tolerant of fumigants than other life stages, sulfuryl fluoride fumigation has been shown to 

be lethal to three-day navel orangeworm eggs when used at the rate of approximately 56.5 mg/L 

(3.5 lb/1,000 cubic feet) for 24 hours, at normal atmospheric pressure (Zettler and Gill, undated). 

USDA/ARS researchers plan to continue testing the efficacy and practicality of using sulfuryl 

fluoride, relative to methyl bromide, to control post-harvest pests of nuts and dried fruit. 

Sulfuryl fluoride thus appears to be an effective methyl bromide alternative for in-shell walnuts. 

Dates

Methyl bromide is used to rapidly fumigate California dates at harvest time, when up to a million 

pounds per day are being harvested within a relatively tight timeframe during the fall. Methyl 

bromide is used on dates at the rate of 1.5 lb/cubic feet. Although several insect may infest 

dates, the carob moth, Ectomyelois ceratoniae, is the more damaging species. The majority of 

dates grown in the United States are fresh dates and sulfuryl fluoride is currently labeled for use 

on dried dates only. Still, the California Date Commission, in collaboration with Dow 

AgroSciences, is currently testing sulfuryl fluoride as a methyl bromide replacement. The 

California Date Commission reports that it is currently testing the efficacy of sulfuryl fluoride on 

dates, with preliminary results showing less than adequate egg kill, even when the amount used 

is twice that needed for a comparable methyl bromide fumigation. 

Dried Fruit

A quick turn-around time for dried fruit at harvest time is the primary justification for the current 

use of methyl bromide, at the rate of 1.5 lb/1,000 cubic feet. Phosphine gas is used for stored 

dried fruit fumigation. Sulfuryl fluoride is currently labeled for use on dried fruit for control of 

USA CUN12 POST HARVEST COMMODITIES 5
Indianmeal moth, raisin moth, Cadra figulilella, dried fruit beetles, Carpophilus hemipterus, 

navel orangeworm, and other insects that infest these commodities. However, citing research 

results presented at the 2009 MBAO meeting (Walse et al., 2009), the California Dried Plum 

Board notes that under low temperatures and current label rates SF efficacy is inadequate against 

dried fruit beetle, red flour beetle, and Indianmeal moth eggs. According to the Dow 

AgroSciences Fumiguide, sulfuryl fluoride is effective against the Indianmeal moth when used at 

a rate of approximately 21 mg/L (1.3 lb/1,000 cubic feet) at normal atmospheric pressure, for 24 

hours, at 80 oF (26.6oF). However, the applicant counters that commodities cannot always be 

treated at 80 oF and that egg stages of target pests may not always be controlled even at these 

temperatures. 

Sulfuryl fluoride and propylene oxide

Wample (2006) is investigating the feasibility of using sequential or combined treatments with 

sulfuryl fluoride and propylene oxide (PPO) as a methyl bromide alternative for control of pest 

of stored products. It is anticipated that this line of research will determine if combinations of 

sulfuryl fluoride and PPO will be more efficacious and cost effective than methyl bromide, 

especially regarding the egg stage of several economically important insects that infest tree nuts 

and dried fruit. 

Propylene Oxide

The U.S. EPA has established tolerances for propylene oxide on prunes, figs, and raisins. 

However, no comparative efficacy data for commodity fumigation seems to be currently 

available. 

Electromagnetic Energy

Ongoing research focusing on the technical feasibility of using radio frequency energy to control 

insect pests infesting in-shell walnuts is yielding promising results. Wang et al. (2006) have 

demonstrated that radio frequency treatment of walnuts can achieve 100% mortality of fifthinstar navel orangeworm larvae at an average walnut surface temperature of 60°C. However, 

60° C for more than a few seconds may shorten the walnut shelf life. 

Phosphine 

Most commodity operations in the U.S. currently use phosphine, alone and in combination, 

whenever feasible. Phosphine is suitable for fumigating commodities in storage, where 

fumigation time is not a factor, but it is generally too slow for treating large commodity volumes 

that need to be processed rapidly. Phosphine its also corrosive to certain metals, and this 

characteristic limits its use in some processing plants, especially those outfitted with electronic 

sorting and processing control equipment 

4. ECONOMIC INFEASIBILITY OF ALTERNATIVES 

TABLE 3. ECONOMIC SUMMARY FOR EACH ALTERNATIVE

USA CUN12 POST HARVEST COMMODITIES 6
METHYL BROMIDE 

ALTERNATIVE

ECONOMIC SUMMARY

PHOSPHINE

Economic losses from additional production downtimes due to longer fumigation time and 

from capital expenditures required to adopt an alternative. Economic losses due to 

downtime with phosphine are persistent. 

SULFURYL 

FLUORIDE

SF is a viable alternative to MeBr; costs per lb are comparable but application rates may be 

higher. Walnuts have inelastic demand; cost increase may be passed to consumers. Higher 

application rates will not change. 

A separate economic analysis of alternatives was conducted for each commodities sub-sector; in 

each case, phosphine was not found to be economically feasible for any of the commodities. For 

phosphine, production downtime was estimated to be 84 days per year on average; total capital 

expenditures for electrical modifications due to corrosive nature of phosphine was assumed to be 

$215 per 1000 m3

. The potential economic losses associated with the use of phosphine mainly 

originate from the cost of production delay. The estimated economic losses are shown in Tables 

E.1 through E.3. The estimated economic losses as a percentage of net revenue are over 100% 

for all CUE applicants in the commodity sector; that is, all applicants experience negative net 

revenues with use of phosphine. 

Walnuts

The United States walnut industry is concentrated in the state of California where production 

averaged 332,000 short tons of walnuts per year from 2003-2007. The largest processor is the 

Diamond Foods in Stockton, California that processes walnut harvest from 1,700 growers in 

California – accounting for approximately 50% of the post-harvest market.1 The United States is 

one of the world’s largest exporters of both shelled and in-shell walnuts.2

 Both production and 

sales peak in the fall in anticipation of the holiday season in December. Approximately 25 

percent of walnuts are sold in the shell.3

 Those that are packed and shipped to European market 

within a couple of days of the fumigation treatment qualify for quarantine exemptions for Methyl 

Bromide use. Those that are sold domestically or not immediately shipped may apply for a 

CUE. The remaining 75 percent of walnuts are processed further to create a variety of packaged 

shelled products. These walnuts must be fumigated before they are put in long-term storage or 

continue in the processing chain due to the key pests. Phosphine can be used for the 75 percent 

of walnuts that are allocated for packaged shelled products because turnaround time is not 

crucial. 

The economic analysis is conducted on a per 1,000 cubic meter basis. Phosphine for the in-shell 

product results in down-time that leads to decreased prices after market window. Sulfuryl 

fluoride results in slightly higher costs due to higher application rates but there is no additional 

downtime. Prices per lb for methyl bromide and sulfuryl fluoride are comparable. Use of 

sulfuryl fluoride results in a 1.65% decrease in net revenue assuming that no costs are passed on 

to the consumer. Given that walnuts have a price elasticity of demand of -0.28 (Russo et al., 

2008), the additional cost of SF fumigant gas could be passed on to the consumer. 

 

1 http://www.diamondfoods.com/growers/ 2 http://www.fas.usda.gov/htp/horticulture/Tree%20Nuts/Walnuts.pdf 3

 

USA CUN12 POST HARVEST COMMODITIES 7
TABLE 4: ANNUAL ECONOMIC IMPACTS OF METHYL BROMIDE ALTERNATIVES FOR WALNUT

Walnuts Units MB Phosphine SF 

Total Commodity Treated kg 

 

301,548,208 

 

301,548,208 301,548,208 

1,000 cubic meters treated kcm 

 

941.25 

 

941.25 941.25 

Avg Mkt Price $/kg $ 1.89 $ 1.55 1 $ 1.89 

Gross Revenue $/kcm $ 6,635.34 $ 497,440.98 $ 606,635.34 

Total Operating Costs $/kcm $ 531,233.52 $ 529,714.86 $ 532,479.97 

Total Fumigation Cost (1x) $/kcm $ 6,934.61 $ 5,200.96 2 $ 7,220.40 

Kg Fumigant per kcm kg/kcm 48.06 na 56.06

Fumigant Cost (i.e., gas) $/kcm $ 1,697.93 na $ 1,980.86 

Other fumigation costs 

(i.e., tarps, etc.) $/kcm $ 5,236.68 $ 5,200.96 $ 5,239.54 

Other Operating Costs $/kcm $ 524,298.90 $ 524,513.89 $ 525,259.57 

Net Revenue $/kcm $ 75,401.83 $ (32,273.88) $ 74,155.36 

 

Time Lost days 0 84 0

Total Loss (MeBr to alt) $/kcm $ - $ 107,675.71 $ 1,246.46 

Loss per Lb MeBr Requested 

$/kg 

MeBr $ - $ 2,240.66 $ 25.94 

Loss as % of GR with MeBr na 17.75% 0.21%

Loss as % of NR with MeBr na 142.80% 1.65%

1 Time lost with phosphine is assumed to result in a lower average market price for walnuts because less would be treated 

during peak prices, and increased supply at other times would depress off-peak prices. 

2 Total fumigation costs; breakdown for gas and operating costs not available. 

Dried Fruit

The dried fruit industry has already replaced a large portion of methyl bromide with phosphine in 

processing dried fruits. 

As in previous analyses, EPA reviewers estimated that having to rely on phosphine alone would 

require an additional 84 days treatment time. In addition to the production loss, there are 

increased costs from using phosphine. Additional expenditures are required to adopt phosphine 

for accelerated replacement of plant and electronic equipment due to the corrosive nature of 

phosphine. The net effect of production losses and cost increases is shown in Table 3. 

TABLE 5: ANNUAL ECONOMIC IMPACTS OF METHYL BROMIDE ALTERNATIVES FOR DRIED FRUIT

Dried Fruit Units MB Phosphine SF 

Kgs of commodity Treated kg 

 

405,882,980 

 

292,235,746 1

 405,882,980 

USA CUN12 POST HARVEST COMMODITIES 8
1,000 cubic meters treated kcm 

 

1,266.92 

 

912.18 1,266.92 

Avg Mkt Price $/kg $ 1.17 $ 0.96 $ 1.17 

Gross Revenue $/kcm $ 374,457.83 $ 307,055.42 $ 374,457.83 

Total Operating Costs $/kcm na na na 

Total Fumigation Costs $/kcm $ 446.75 $ 544.28 $ 542.87 

Quantity of Fumigant per unit Kgs/kcm 24.03 na 40.05 

Fumigant Cost (i.e., gas) $/kcm $ 144.17 $ 144.17 $ 240.28 

Other fumigation costs (i.e., 

tarps, etc.) $/kcm $ 302.59 $ 302.59 

$ 

302.59 

Other Operating Costs $/kcm na $ 97.52 na 

 

Time Lost days 0 84 0 

Total Annual Loss (MeBr to alt) $/kcm $ - $ 67,499.93 $ 96.11 

Annual Loss per Lb MeBr Requested 

$/kg MB 

requested $ - $ 2,809.26 $ 4.00 

Loss as % of GR with MeBr na 18.03% 0.03% 

1 Time lost with phosphine is assumed to result in a lower dried fruit produced overall resulting in lower gross revenues. 

Dates

An economic analysis was not done for dates because sulfuryl fluoride is labeled specifically for 

“dates, dried” and efficacy tests have not been conducted for this alternative. 

USA CUN12 POST HARVEST COMMODITIES 9
CITATIONS

Fields, P. and N. D. G. White. 2002. Alternatives to methyl bromide treatments for storedproduct and quarantine insects. Annual Review of Entomology 47:331-59. 

Leesch, J.G. undated. The use of 3 fumigants on walnuts to control diapausing codling moth 

 larvae. USDA-ARS report. At: 

http://www.mbao.org/1999airc/76leesch.pdf

Muhareb, J. and P. Hatsell. undated. Laboratory evaluation of the toxicity of sulfuryl fluoride in 

vacuum fumigations for diapausing larvae of the codling moth, Cydia pomonella, and 

larvae of the navel orangeworm, Amyelois transitella, in plugged walnuts. Dow 

AgroSciences internal report. 

Phillips, T., P. Bolin, and G. Mbata. 2006. Vacuum for post harvest disinfestation of insects from 

 durable and fresh commodities. CSREES Funded Post-harvest project. At: 

 http://www.oardc.ohio-state.edu/nc213/PR06.pdf 

Russo, C., Green, R.D. & Howitt, R.E. “Estimation of Supply and Demand Elasticities of 

California Commodities”. Department of Agricultural and Resource Economics 

University of California, Davis, Working Paper No. 08-001, June 2008. 

Schneider, S.M., E.N. Rosskopf, J.G. Leesch, D.O. Chellemi, C.T. Bull, and M.Mazzola. 2003. 

United States Department of Agriculture – Agricultural Research Service research on 

alternatives to methyl bromide: pre-plant and post-harvest. Pest Manag. Sci. 59:814-826. 

Walse, S.S., J.G. Leesch, and S. Tebbets. 2009. The ovicidal efficacy of sulfuryl fluoride on 

insect pests of dried fruit and nuts. USDA/ARS, San Joaquin Valley Agricultural Sciences 

Center, Parlier, CA 93648. 

Wample, R.L. 2006. Efficacy with the combination of sulfuryl fluoride and propylene oxide as 

replacement for methyl bromide fumigation of stored food product. CSREES Funded Postharvest project. At: http://cris.csrees.usda.gov/cgibin/starfinder/0?path=icgpmbtlink.txt&id=anon&pass=&search=CG=*-51102-

*%20and%20gy%3e1999&format=WEBTITLESG

Wang, S., M. Monzon, J.A. Johnson, E.J. Mitcham, and J. Tang. 2007. Industrial-scale radio 

 frequency treatments for insect control in walnuts II: Insect mortality and product quality. 

 Postharvest Biol Technol 45:247-253. 

Wood, M. 1999. Walnut pests foiled by fumigant, studies show. News & Events, USDA/ARS. 

 At: http://ars.usda.gov/is/pr/1999/991105.htm

Zettler, J.L. and J.G. Leesch. 2000. Sulfuryl fluoride: A disinfestation treatment for 

 walnuts and almonds. USDA/ARS. Vol. 6, No. 2. At: 

http://www.ars.usda.gov/is/np/mba/apr00/sulf.htm

USA CUN12 POST HARVEST COMMODITIES 10
USA CUN12 POST HARVEST COMMODITIES 11

Zettler, J.L. and R.F. Gill. undated. Sulfuryl fluoride: A disinfestation treatment for 

 walnuts and almonds. USDA/ARS report. At: http://mbao.org/1999airc/108zettl.pdf