USA CUN14 POST HARVEST -- Dry, Cured Pork Products Page 1

METHYL BROMIDE CRITICAL USE RENOMINATION FOR POSTHARVEST -- DRY CURED PORK PRODUCTS

NOMINATING PARTY: The United States of America

FILE NAME USA CUN14 POST HARVEST -- DRY, CURED PORK PRODUCTS

BRIEF DESCRIPTIVE TITLE OF NOMINATION:

Methyl Bromide Critical Use Nomination for Post Harvest Use on Dry Cured Pork Products

(Submitted in 2011 for 2014 Use Season)

STRUCTURE, COMMODITY OR OBJECT TREATED:

This sector is for the production of cured meat products, such as country hams. These are 

produced primarily in the southern U.S. This sector has no known viable alternative currently 

available. 

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)

2014 3,730 kg

(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: Federico San Martini, Ph.D.

Title: Foreign Affairs Officer

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) 647-3819

Fax: (202) 647-1052

E-mail: SanMartiniFM@state.gov

Following the requirements of Decision IX/6 paragraph (a)(1) 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
USA CUN14 POST HARVEST -- Dry, Cured Pork Products Page 2

Signature Name Date

Title: 

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

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 CUN14 Post Harvest Ham

* Identical to paper documents
USA CUN14 POST HARVEST -- Dry, Cured Pork Products Page 3

METHYL BROMIDE CRITICAL USE RENOMINATION FOR POSTHARVEST -- DRY CURED PORK PRODUCTS

1. SUMMARY OF NEED FOR METHYL BROMIDE AS A CRITICAL USE

Currently there are no viable alternatives to methyl bromide for the dried meat industry: heat 

would alter the product, and phosphine has failed to control mites, a major pest. Sulfuryl 

fluoride received federal registration and has been tested for efficacy against the mites and other 

pests of cured meat products. Although mortality of the red-legged ham beetle occurred at levels 

below maximum rates of sulfuryl fluoride, the same cannot be said for the ham mites (Phillips, et 

al., 2008). Control of the ham mites took three times the legal limits of sulfuryl fluoride 

(Phillips, et al., 2008). At the time of this nomination, there are no known registered alternatives 

for use on hams in the U.S. that provide the same level of mite control as methyl bromide.

This industry is cooperating with university researchers to find technically and economically 

feasible alternatives to methyl bromide. Dry, cured pork producers no longer fumigate with 

methyl bromide on a monthly schedule, but monitor and fumigate when pests are detected. 

Many producers use pheromone traps to monitor for pests (Arthur and Phillips, 2003). Producers

improved sanitation in their curing facilities. Producers have modified their buildings to make 

them more gas-tight, not only to try to exclude pests, but also to retain methyl bromide better. 

Some companies eliminated grass, trees, and shrubs from their buildings and replacing them with 

gravel, as suggested by researchers in 2008, to reduced harborage for pests outside their aging 

houses. These efforts have reduced their use of methyl bromide, but have not eliminated the 

need to disinfest their dry, cured pork products. 

This industry currently has no viable chemical or non-chemical alternative available. Although 

some measures, listed in the above paragraph, have reduced the number of times fumigation is 

needed in some facilities, it has not eliminated the need for fumigation. Therefore, methyl 

bromide remains critical to this industry. 
USA CUN14 POST HARVEST -- Dry, Cured Pork Products Page 4

TABLE 2. NOMINATION AMOUNT 

2. SUMMARIZE WHY ALTERNATIVES ARE NOT FEASIBLE

This industry currently has no viable chemical or non-chemical alternative available. Although 

its IPM measures has reduced the number of times fumigation is needed, it has not eliminated the 

need for fumigation. Therefore, methyl bromide remains critical to this industry. 

3. UPDATE OF RESEARCH RESULTS SHOWING EFFICACY OF ALTERNATIVES

Researchers are actively investigating the control of arthropod pests that infest dry cured pork 

products during the aging process. 

Research Results

Fumigation trials were conducted in May, October, and November 2011 in 1000-cubic meter 

shipping containers intended to simulate dry cured aging ham houses at phosphine 

concentrations ranging between 1000-2000 ppm and exposure times of 48 or more hours. 

Temperature was measured in the ham houses during fumigation and twenty Tyrophagus 

putrescentiae (ham mites) bioassay jars and ten Necrobia rufipes (red-legged ham beetles) jars 

were placed in each shipping container for each trial. Ten dry cured hams were hung from racks 

in shipping containers to simulate dry cured aging conditions. Five of these hams were used for 

mite inoculation and the other 5 hams were used for sensory analysis and phosphine residue 

testing. The lean portion of the dry cured hams (that were used for inoculation) was also 

inoculated with a mixed culture of approximately 1000 mites. Phosphine gas was produced in 

the shipping containers using magnesium phosphide cells that reached target fumigation doses at 

 Gwaltney of 

Smithfield 

 National 

Country Ham 

Association 

 Nahunta Pork 

Center 

 American 

Assoc. of Meat 

Processors 

 Sector Total 

Quantity Requested for 2013: Amount (kgs) 726 709 91 2,204 3,730

Quantity Recommended by 

MBTOC/TEAP for 2013 :

Amount (kgs) 726 709 91 2,204 3,730

Amount (kgs) 726 709 91 2,204 3,730

Volume (1000 m3) 56 42 5 110 -

Rate 13 17 18 20 -

Transition from 2014 Baseline 

Adjusted Value

Percentage (%) 0% 0% 0% 0% -

Amount (kgs) 726 709 9 1 2,204 3,730

Volume (1000 m3) 56 42 5.1 110 -

Rate 13 17 18 20 -

Transition Use Reduction Description Spreadsheet

HAM

Quantity Approved by Parties for 

2013:

Quantity Required for 

2014 Nomination:

SECTOR

2014 Methyl Bromide Usage Newer Numerical Index (BUNNI) 
USA CUN14 POST HARVEST -- Dry, Cured Pork Products Page 5

between 8 to 12 hours after the fumigation was started. Phosphine concentration was measured 

in the shipping containers using both Dräger tubes and a calibrated UV-VIS detector.

The post-embryonic mite mortality was 99.8% in the bioassays at two weeks post fumigation

when 2000 ppm phosphine was achieved, but the eggs on either the hams or in the bioassays 

were not controlled, even at concentrations as great as 2000 ppm. The next phase of the study 

will be to fumigate in spring 2012 at 2000 ppm for 72 hours to determine if greater control of 

ham mite eggs can be reached with a longer exposure time when the temperature is greater than 

20o C. A trial fumigation of 72 hrs in November 2011 had been planned; however, the ambient 

temperature was already too cold (<15o C) to achieve successful control of ham mites in this 

follow up trial. (Schilling & Phillips, personal communication)

Earlier investigations presented at 2010 MBAO, demonstrated that at temperatures of 20o C or 

greater, all life stages of Necrobia rufipes (red legged ham) beetles were controlled in all 

phosphine fumigation trials. Variations in test conditions indicated that temperatures and 

exposure times need to be optimized for fumigation since 48 hours was not long enough to 

control ham mites at 2000 ppm and ambient temperatures below 15o C decreased the 

effectiveness of the fumigation against both ham mites and red legged beetles. Sensory tests 

indicated that trained panelists could not determine differences between phosphine treated dry 

cured hams and non-fumigated hams. In addition, residual phosphine concentrations were below 

the legal limit of 0.01 ppm in ham slices that were taken from phosphine fumigated hams. Thus 

maintenance of post-treatment market quality and food safety support continued research on 

efficacy of phosphine fumigation for hams. (Phillips, et al. 2008)

Previous USG nominations described the failure of sulfuryl fluoride, carbon dioxide, and ozone 

to control ham mites and red legged ham beetles. USG previously reported the results of low 

pressure and low oxygen concentrations on ham mites under laboratory settings, which took too 

long to be a viable option at this time. 

There is still no technical alternative for methyl bromide for the dry cured ham industry at this 

point in time. Research is still ongoing with phosphine, but more research and commercial 

applications need to be conducted before any treatment can be considered an alternative to 

methyl bromide for treatment of ham (mold) mites. 

Funding

In the spring of 2007, a proposal was submitted to the USDA Integrated Research, Education, 

and Extension Competitive Grants Program- Methyl Bromide Transitions (CSREES-MBT) by 

several meat scientists and one entomologist. A no-cost extension was granted for 2010-2011, 

and additional funding has been provided through the Southern Regions Integrated Pest 

Management Center to continue research efforts for 2010 and 2011. 

The researchers successfully competed for a USDA-MBT grant to support their investigations. 

The new funding is for 2011-2013, with a potential no-cost extension into 2014. This research 

will start in January 2012 and is a collaborative effort between Mississippi State University, 

Kansas State University, and Oklahoma State University. In addition, all the research projects 
USA CUN14 POST HARVEST -- Dry, Cured Pork Products Page 6

are being conducted in conjunction with the National Country Ham Association, The American 

Association of Meat Processors, individual ham producers, and fumigant companies. 

4. REGISTRATION UPDATE

No new chemicals have been registered or de-registered since the last nomination. 

5. ECONOMIC INFEASIBILITY OF ALTERNATIVES

An economic analysis was not conducted because this sector has no technically feasible 

alternatives at this time. 

CITATIONS

Phillips, T.W. Hasan, M.M., Aikens, M.J., Schilling, M.W. 2008. Efficacy of sulfuryl fluoride 

to control ham mites and red-legged ham beetles. Annual International Research 

Conference on Methyl Bromide Alternatives and Emission Reduction, Orlando, FL, 

November 11th-14th

Schilling, W. and T. W. Phillips, 2011. Personal Communication.