USA CUN13 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 CUN13 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 2013 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)

2013 3,730

(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: Foreign Affairs Officer

Address: Office of Environmental Policy

U.S. Department of State

2201 C Street, N.W. Room 2658

Washington, D.C. 20520

U.S.A.

Telephone: (202) 647-1123

Fax: (202) 647-5947

E-mail: ThompsonJH@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 CUN13 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 CUN13 Post Harvest Ham

* Identical to paper documents
USA CUN13 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 may not 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 pest control as methyl bromide.

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

feasible alternatives to methyl bromide. In the meantime, this industry is using IPM techniques 

to manage their pest populations. All use sanitation to keep their curing facilities clean. Several 

companies have modified their buildings to make them more gas-tight. Some companies are 

eliminating grass, trees, and shrubs from their buildings and replacing it with gravel, as 

suggested by researchers in 2008. Many use pheromone traps; however, these traps only used 

for monitoring purposes at this time (Arthur and Phillips, 2003). 

This industry currently has no viable chemical alternative available. Although its IPM measures 

may 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. 

TABLE 2. NOMINATION AMOUNT 

 Gwaltney of 

Smithfield

 National 

Country Ham

Association 

 Nahunta Pork

Center

 American 

Assoc. of Meat 

Processors 

 Sector Total / 

Average

Quantity Requested for 2012: Amount (kgs) 726 709 91 2,204 3,730

Quantity Recommended by 

MBTOC/TEAP for 2012 :

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

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

Volume (1000 m3) 56 42 5 110 213

Rate 13 17 19 20 18

Transition from 2012 Baseline 

Adjusted Value

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

Amount (kgs)

 726 709 91 2,204 3,730

Volume (1000 m3) 36 35 5 110 187

Rate 20 20 20 20 20

HAM

Quantity Approved by Parties for 

2012:

Quantity Required for

2013 Nomination:

SECTOR
USA CUN13 POST HARVEST -- Dry, Cured Pork Products Page 4

2. SUMMARIZE WHY ALTERNATIVES ARE NOT FEASIBLE

This industry currently has no known viable chemical alternative available. Although its IPM 

measures may have 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. RESEARCH RESULTS SHOWING EFFICACY OF ALTERNATIVES

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

products during the aging process. In the spring of 2007, a proposal was submitted to the USDA 

CSREES Integrated Research, Education, and Extension Competitive Grants Program- Methyl 

Bromide Transitions by several meat scientists and an entomologist. This proposal was funded

from 2007 to 2010. 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. In addition, a grant will be submitted to the USDA in 2011 

to seek funds to continue research with respect to potential alternatives to methyl bromide for use 

in the dry cured pork industry. All of the research projects listed above and below are being 

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

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

There were several objectives to the research project that was funded by the USDA MBT 

program from 2007-2010. The first objective was to determine the effectiveness of chemical 

controls (sulfuryl fluoride, phosphine, and methyl bromide) against all life stages of both mold 

mites (Tyrophagus putrescentiae) and red legged ham beetles (Necrobia rufipes). The second 

objective was to determine the effectiveness of carbon dioxide and ozone against all life stages 

of both mold mites and red legged ham beetles. The third objective was to test the effects of 

sulfuryl fluoride, phosphine and methyl bromide on the quality and safety of the dry cured hams. 

The fourth objective was to conduct an economic analysis of the alternatives demonstrated to be 

technically viable alternatives for methyl bromide in this industry. 

The results of sulfuryl fluoride efficacy investigations on Tyrophagous putrescentiae, ham mite, 

and Necrobia rufipes, red-legged ham beetle, were presented at the 2008 MBAO Conference, in 

Orlando, FL. The studies included eggs and a mixture of adults and large nymphs of mites and 

the eggs, large larvae, pupae and adults of beetles. The experiments were conducted for 48 hours 

at 23° C at various concentrations of sulfuryl fluoride. The investigators achieved 100% 

mortality of red-legged ham beetle adults and pupae at about 4.0 g/m3, and 100% mortality of 

larvae at 5.7 g/m3. Eggs of red-legged ham beetles died at 24.0 g/m3of sulfuryl fluoride, well 

below the maximum label rate (Phillips et al., 2008). Mortality of ham mites required much 

higher concentrations of sulfuryl fluoride. A concentration of about 100.3 g/m3 was necessary to 

obtain 100% mortality of adults and nymphs under the test conditions. However, this 

concentration obtained only a 95% mortality of mite eggs. This is about three times the legal 

label rate of sulfuryl fluoride (Phillips et al., 2008) and thus indicates that sulfuryl fluoride is not

a viable alternative to methyl bromide for controlling ham mites. In addition, results also 

indicated that levels of residual fluoride and sulfuryl fluoride in the hams were linearly related to 

fumigant concentration and that use of high concentrations of sulfuryl fluoride (72 g/m3or 
USA CUN13 POST HARVEST -- Dry, Cured Pork Products Page 5

greater) and multiple fumigations could potentially lead to high concentrations of sulfuryl 

fluoride and fluoride in the ham (Sekhon et al., 2010a). 

The results of carbon dioxide, phosphine, methyl bromide and ozone efficacy investigations on 

Tyrophagous putrescentiae, ham mite, and Necrobia rufipes, red-legged ham beetle, were 

presented at the 2009 MBAO Conference, in San Diego, CA (Sekhon et al., 2009a, b; Phillips, 

2009, Sehkon et al., 2010b, 2010c). The studies included eggs and a mixture of adults and 

nymphs of mites and eggs, large larvae, pupae and adults of beetles. The experiments were 

conducted for variable times at 23° C at various concentrations of carbon dioxide, phosphine, 

methyl bromide and ozone. The investigators achieved mortality of all life stages of mites with a 

concentration of 60 % carbon dioxide with 144 hr of exposure (Sekhon et al., 2009a; Phillips, 

2009; Sehkon et al., 2010b). However, fumigation with carbon dioxide would likely not be 

applicable since ham structures are not air-tight and 144 hr is too long of a time to fumigate the 

hams. In addition, a carbon dioxide concentration (> 80 %) with an exposure time of 144 hrs 

was necessary to cause 100 % mortality for all life stages of red legged ham beetles (Sekhon, et 

al. 2009a; Phillips, 2009; Sehkon et al, 2010b). In addition, there may be higher numbers of ham 

mites that can hide in the crevices of the ham that may be able to survive during CO2 fumigation. 

Investigators achieved 100 % mortality of all life stages of red legged ham beetles and ham mites 

with 48 hours exposure of 400 and 1000 ppm of phosphine, respectively (Sekhon, et al. 2009b; 

Phillips, 2009; Sekhon et al., 2010c). In addition, residual phosphine concentrations in dry cured 

hams that were fumigated for 48 hrs at 1000 ppm were below 0.01 ppm, the legal residual limit 

in stored food products (Sekhon, et al. 2009b; Sekhon et al., 2010c), and consumer panelists 

could not detect differences between control and phosphine fumigated samples at 1000 ppm 

(Sekhon et al. 2009b; Sekhon et al., 2010c). Therefore, phosphine can now be considered a 

potential alternative to methyl bromide for controlling arthropod pests of southern dry cured 

hams. Further testing with a greater number of mites has indicated that a greater concentration 

of phosphine (>1000 ppm) is likely necessary to kill substantial mite infestations. In addition, 

commercial applications of phosphine are planned for 2010-2011 to determine the efficacy of 

using phosphine at the plant level. The effectiveness of phosphine will be evaluated through the 

use of both bioassays (with ham present) and on hanging hams in a simulated dry cured ham 

aging room. 

Other portions of this research include the economical analysis of using phosphine in comparison 

to methyl bromide, if it is effective at eradicating mites. Commercial applicators and agricultural 

economists are working with us on this portion of the research. Additional items that will be 

researched in the future (if funding is obtained) include the effect of multiple fumigations on the 

sensory quality and residual concentration of phosphine in ham, and the effectiveness of using 

phosphine in dry cured ham facilities. Many processors have indicated that they would be 

willing to help evaluate the efficacy of phosphine (at controlling ham mite infestations) in their 

plant as part of a research project, which truly demonstrates the willingness of the industry to do 

everything that they can to help determine if potential alternatives to methyl bromide exist. In 

addition, we have commitments from Universities and a commercial applicator to help 

implement phosphine fumigation in dry cured ham facilities for this research to take place. 
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Ozone concentrations of greater than 150 ppm for 48 hrs were able to achieve 100 % mortality of 

ham beetles and mites at the bench top level (Sekhon et al., 2009b; Phillips, 2009; Sekhon et al., 

2010b). Consumers also could not determine sensory differences between control hams and 

those that were fumigated with ozone at 175 ppm for 48 hrs (Sekhon et al., 2010b)). However, 

ozone is not able to penetrate surfaces well and therefore may not work well in real world 

applications since ham mites could potentially penetrate into crevices in the meat and ham 

beetles bore through the meat tissue. Research that was conducted by one dry cured ham 

processor indicated that the use of ozone in a commercial setting was not effective at eradicating 

ham mite infestations, which was likely due to the inability of the ozone to penetrate the surface 

of the ham and the ability of mites to find places to hide where the ozone did not reach. 

However, ozone may play a role in integrated pest management to help minimize infestations 

and enhance sanitation since it would sanitize areas in the plant as well as equipment that could 

potentially harbor bugs and pathogens.

Further research has recently been conducted on the effects of low pressure and low oxygen 

concentration on the mortality of Tyrophagous putrescentiae (mold mites). Exposure of mites to 

low oxygen with pressure (25 mmHg; approx. 3.0% O2) at 23°C for 144 hrs or greater was 

effective at eradicating more than 95 % of each mite life stage (Hasan et al., 2010). However, 

testing with a larger number of mites and under commercial conditions would need to be 

conducted to determine if this technology could be considered a potential alternative to methyl 

bromide. Its limitations include length of application, ability of mites to hide within meat 

crevices, and difficulty in implementing at the plant level. 

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

point in time. Research is still ongoing with phosphine, and controlled atmosphere, but more 

research and commercial applications need to be conducted before any of these 

treatments/fumigants can be considered alternatives to methyl bromide for treatment of ham 

(mold) mites. 

4. REGISTRATION UPDATE

No new chemicals have been registered nor 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

Arthur, F. and T. W. Phillips. 2003. Stored-product insect pest management and control, In: 

Food Plant Sanitation eds: Y. H. Hui, B. L. Bruinsma, J. R. Gorham, W. Nip, P. S. Tong, and 

P. Ventresca. Marcel Dekker, Inc., New York, pp. 341-358. 
USA CUN13 POST HARVEST -- Dry, Cured Pork Products Page 7

Hasan, M.M., Phillips, T.W., Aikins, J.M., Schilling, M.W. 2010. Controlled atmosphere 

treatments to control arthropod pests of American dry cured hams. Annual International 

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

FL, November 1st-5

th

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

Phillips, T.W. 2009. Personal Communication.

Sekhon, R.K., Schilling, M.W., Phillips, Hasan, M.M., Aikens, M.J, Mikel, W.B. 2009.

Chemical Composition of Dry Cured Hams Fumigated with Carbon Dioxide. Annual 

International Research Conference on Methyl Bromide Alternatives and Emission 

Reduction, San Diego, CA, November 10th-13th

Sekhon, R.K., Schilling, M.W., Phillips, Hasan, M.M., Aikens, M.J, Mikel, W.B. 2009. 

Chemical composition of dry cured hams fumigated with phosphine. Annual International 

Research Conference on Methyl Bromide Alternatives and Emission Reduction, San Diego, 

CA, November 10th-13th

Sekhon, R.K., Schilling, M.W., Phillips, T.W., Hasan, M.M., Aikens, M.J. Mikel, W.B. 2010a. 

Sulfuryl fluoride fumigation effects on the safety, volatile composition, and sensory quality

of dry cured ham. Meat Science. 84(3):505-511.

Sekhon, R.K., Schilling, M.W., Phillips, T.W., Hasan, M.M., Aikens, M.J., Nannapaneni, R., 

Mikel, W.B. 2010. Effects of carbon dioxide and ozone treatments on the volatile 

composition and sensory quality of dry cured ham. J. Food Science. 75(5):452-458.

Sekhon, R.K., Schilling, M.W., Phillips, T.W., Hasan, M.M., Aikens, M.J., Corzo, A. Mikel, 

W.B. 2010. Effects of phosphine and methyl bromide fumigation on the volatile flavor 

profile and sensory quality of dry cured ham. Meat Science. 86(2):411-417.