USG Responses to MBTOC QSC Page 1

Structures (mills)

1. We note that there is no decrease in MB use planned between 2010 and 2011 for rice 

milling and pet foods. These sectors had previously made year over year decreases in 

their MB use. Could you please provide the explanation(s) for the inability of these 

sectors to continue to decrease MB use? 

USG Response

In the judgment of USG no further transition is possible at this point for either rice mills 

or pet food facilities due to regulatory barriers. The remaining pet food facilities produce 

products that include elements not on the sulfuryl fluoride (SF) label (which also does not 

include a registered category “pet food”) limiting further uptake of SF unless there is a 

change in the registration of SF or the registration of another alternative,. Pet food 

manufacturers have reduced the frequency of methyl bromide fumigations so as to 

minimize the use of methyl bromide as much as technically feasible and now the average 

frequency is once every 3-5 years. Reducing the frequency further is not possible with 

current alternatives.

In the case of rice mills, further reduction of methyl bromide use is not economically 

feasible. In order to obtain a complete kill of all life stages it is necessary to have either 

much higher rates of sulfuryl fluoride use (in some cases to levels that exceed label rates) 

or a facility temperature of approximately 1400F (approximately 1250C). In warm areas, 

where facility temperatures average 850F, heating the facility can be accomplished at 

moderate expense. In colder areas where the facility temperature may average 40oF, the 

cost of heating the facility to obtain a complete kill is prohibitive. See table six below

outlining the economic infeasibility of further reductions in thee particular portions of the 

sector.

2. We understand the current regulatory situation for sulfuryl fluoride does not allow the 

treatment of some foods, such as pet foods and that this regulatory situation makes the 

use of SF difficult in some facilities. This may also be a problem for some rice and flour 

millers. However, in the MBTOC text box for 2008, we suggest that ways of segregating 

the food during facility fumigation be researched and assessed. (See text excerpt below.) 

Can USG tell us if trials of these methods have been conducted and the results of those 

investigations? 

Excerpt of MBTOC/TEAP, April 2008 text box for US CUN structures provided for ease 

of reference: “Pet food facilities could, however, expand use of full site or spot heat 

treatment, utilizing appropriate pest barrier methods to prevent pest escape from spot 

heat treatments.” And, “The three sectors included in this CUN are expected to work to 

improve treatment logistics that improve product segregation so that more adoption of 

alternatives can be accomplished even if regulatory barriers to the use of SF persist. 

When conducting SF fumigations where food mixes are present, the applicant could trial 

tarping off the food under positive pressure or removing food ingredients and mixes to 

non-fumigated areas or sealing off stored product warehouses to allow SF treatment of 

facility while ensuring that food is not exposed.” 

USG Response
USG Responses to MBTOC QSC Page 2

Both the Pet Food Institute and the National Pest Management Association are 

considering testing these strategies but have not yet done so, in part because of recent 

budgetary concerns. They are discussing this option with their fumigators to determine 

its potential. We will keep the MBTOC informed of further developments when they 

occur. 

3. We are having difficulty understanding the headings on the economic assessment 

tables 5, 6, and 7. If the heading 7°F means the cost of raising the facility’s temperature 

by 7°F what would the heading 29°F mean? The CUN notes that mill temperature 

averages 29.44°C. If an additional 7°C is added, the resulting temp would be 36.44°C, 

which is insufficient for a heat treatment (50°C is required). 

USG Response

On all structures assessments (rice mills, flour mills, and pet food), the 7oC and 29oC in 

the headings were incorrect but this will not change the costs in the assessment. The 

assessment was originally conducted on the Fahrenheit scale and then converted to 

Celsius. The temperature of an average facility (called a “warm facility” in the column 

heading) was assumed to be around 85oF (29.4oC). The temperature of a cold facility was 

assumed to be around 40oF (4.4oC). To heat the warm facility from 85o to 130oF (the 

temperature needed for total kill) required a 45oF increase in temperature which was 

converted to 7oC but a 7o change in temperature on the Celsius scale does not reflect a 45o 

change in temperature on the Fahrenheit scale, hence the 7o was not the correct value to 

enter in the heading. Instead it should have reflected the change from 85oF to 130oF in 

terms of Celsius so it should have read “Heat: 25oC” or the difference between 29.4oC 

and 54.4oC.

The prices in the table, however, will remain unchanged. A heat treatment needs to warm 

the facility to 130o-140oF (54o-60oC) for total kill. So the assessment for a warm facility 

(i.e., a facility with an indoor temperature of 85oF) simply used a reasonable estimate of 

costs provided by a heat treatment company. The company that we contacted provided a 

cost range of $0.02 to $0.15 per cubic foot with $0.07 being the average and $0.15 being 

a worst case scenario (i.e., extreme cold and a lot of building partitions). 

The cost of a heat treatment for warm facility (85oF or 29.4oC) assumed a cost of 

$0.07/cu ft to raise the temperature 45oF to reach 130oF. The cost of a heat treatment for 

a cold facility (40oF or 4.4oC) assumed the worst-case scenario and set the cost at 

$0.15/cu ft for heat treatment. The cost of the combination of SF + Heat treatment used 

the cost of SF from the second column plus $0.07/cu ft for heat. The difference between 

29.4oC and 54.4oC is the same as the different between 4.4oC and 29.4oC. This would be 

an example where a very cold facility used heat to boost the efficacy of an SF treatment. 

The column headings are corrected in the revised Table 6. (See below)

Mills and NPMA

4. Why is the implicit per kg price for MB and SF $42.48 for Pet Food while the price per 

kg is $13.22 for MB and SF in Rice Mills and NAMA? Implicit price is calculated by 

dividing fumigant cost (i.e. gas) per year by quantity of fumigant per year. 
USG Responses to MBTOC QSC Page 3

USG Response

The calculations for kgs per facility, fumigant cost, and other fumigation costs were 

incorrect in the pet food table. The total fumigation costs, however, are unchanged. 

Total fumigation costs were derived from information provided in the application and the 

average cost of SF ($6/lb) used throughout the assessment. The application states that a 

rate of 1.15 lbs/1,000 cu ft is needed to treat a pet food facility and that each facility is 

treated one time every 3-5 yrs or approximately 0.25x/yr. The annual cost of fumigation 

provided by the applicant in Worksheet 2-D is $38,450 but this appears to actually reflect 

the cost of one MB fumigation, not the “annual” cost which would be the cost of a single 

fumigation spread over four years. 

The calculations are corrected in the revised Table 6. (See below)
USG Responses to MBTOC QSC Page 4

TABLE 6: ANNUAL ECONOMIC IMPACTS OF METHYL BROMIDE ALTERNATIVES FOR PET FOOD INSTITUTE

Pet Food 1 Units MeBr 2SF 2

Warm Facility: 

Heat from 29.4oC 

to 54.4oC

Cold Facility: 

Heat from 4.4oC 

to 54.4oC

Cold Facility: SF 

+ Heat from 4.4oC 

to 29.4oC

Gross Revenue $/year $ 33,176,000 $ 33,176,000 $ 33,176,000 $ 33,060,000 $ 33,176,000 

Total Operating Costs $/year na na na na na 

Total Fumigation/Heat Costs $/year $ 9,613 $ 11,638 $ 17,500 $ 37,500 $ 29,138

Quantity of Fumigant

 (0.25 treatment per year)

Kgs/facility

/ treatment 522 1,134 na na na

Fumigant cost (i.e., gas) $/year $ 1,725 $ 3,750 na na $ 3,750

Other fumigation costs 

(i.e., labor, equip., etc.) $/year $ 7,888 $ 7,888 $ 17,500 $ 37,500 $ 25,388

Other Operating Costs $/year na na na na na 

Time Lost days 0 0 0 1 0

Total Loss (MeBr to alt) $/year $ - $ 2,025 $ 7,888 $ 27,888 $ 19,525 

Average Facility Loss per Kg 

MeBr Requested

$/kg MB 

requested $ - $ 110 $ 428 $ 1,514 $ 1,060

Loss as % of GR with MeBr 0% 0.01% 0.02% 0.08% 0.06%

1 Analysis for a 28,317 cubic meter (1,000,000 cubic foot) facility

2 Temperature 29.44 degrees C (85 degrees F)
USG Responses to MBTOC QSC Page 5

5. MBTOC is trying to clarify the use of MB in flour milling and food processing in North 

America through a better understanding of industry sector structure. Some mills included 

in the flour milling CUN also seem to be producers of bakery and cereal mixes and other 

processed foods. Yet, processed foods manufacturers are included in NPMA. Last year

USG indicated that about 58% of mills do not prepare bakery mixes. Can USG provide 

further clarification of percentage breakdown available, showing for example, the 

percentage of mills which only mill grain, the percentage which both mill grain and also 

prepare bakery and cereal mixes, and also the percentage which also produce prepared 

foods? 

USG Response

USG believes that 58% of mills mill grain but do not produce bakery mixes and so are 

eligible to use sulfuryl fluoride assuming that such use is economically feasible. The 

remaining 42% of mills both mill grains and produce bakery mixes so that until another 

product is registered, there is a change in the sulfuryl label, or some means of segregating 

inputs and product from the fumigation, these facilities will be unable to transition.

Cured Pork Products and Facilities

6. We note, with interest, the multi-university research program for control of pests in 

this sector. We are aware of the results with sulfuryl fluoride. However the research 

program has five different objectives; results obtained with the other alternatives have 

not been reported. If any of these studies are completed between now and September 

2009, we request that USG send the results to MBTOC.

USG Response

USG will share results as they become available. However, the multi-university research 

program is funded for 3 years with a possible extension of 2 more years. The research is 

continuing. 

7. The CUN reports that heat would alter the product. The MBTOC text box (October, 

2008) makes a suggestion about a heat treatment that might effectively control pests in 

this commodity. What method was used in the US to test the effect of heat treatment 

which resulted in the conclusion in the CUN? Was the method MBTOC suggested 

tested? Are there plans to test the method MBTOC suggested? 

Excerpt of MBTOC/TEAP October 2008 US cured pork products text box provided for 

ease of reference. “MBTOC recommends a CUE of 4.465 tonnes for specific cured (airdried) pork products in 2010. This CUN has decreased by 14.533 tonnes over the amount 

granted by the Parties for 2009. The USG is in the second of a three year multidisciplinary research program to try to find non-MB methods to control mites in this 

traditional cured pork product and associated storage houses. No chemical alternatives 

are registered for pest control in these products. Although MBTOC does not know of 

methods that have been published as effective for this situation. In the interest of 

contributing to research ideas, we can suggest: low oxygen controlled atmosphere; or 

dipping the hams in oil and lard at 90oC as practised in Spain with a similar product.
USG Responses to MBTOC QSC Page 6

MBTOC comments on economics: No economic data given. This is a minor use and there 

is little economic incentive to develop alternatives”

USG Response

At this time, neither the industry nor the researchers have investigated these techniques. 

However, at the 2008 MBAO conference, the researchers informed us that they are 

planning on investigating these alternative techniques. When the researchers are ready to 

start these investigations they do intend to contact MBTOC for more specific 

information.