Environment & Resources Division

Date May 31, 2011

To Jeremy Arling, EPA/OAP/SPD

From Albert Acquaye, Abt Associates

Subject Analysis of a Major U.S. Methyl Bromide Supply Disruption: The Potential Role of 

Imports 

This memorandum presents the results of our analysis to update the estimate of necessary 

domestic methyl bromide inventories in the event of a major domestic supply disruption. Based 

on our update of the prior analysis we project that 105 to 429 MT (10 to 42 percent of annual 

2012 demand) would be required in case of a major domestic supply disruption.

We update the following data from the 2010 analysis in order to obtain new estimates for 2012:

1) U.S. consumption of critical use methyl bromide is updated from 2011 to 2012. The 

2011 number, from the 21st Meeting of the Parties to the Montreal Protocol, is updated 

with the amount authorized for U.S. consumption at the 22nd Meeting of the Parties1

. 

The updated amount for 2012 is 1,023 MT.

2) Annual critical stock allowance (CSA) allocations and expenditures are updated for 2010 

and added for 2011 (Table 1). Expended CSA for 2010, which had been projected based 

on a ratio of 70 percent expended-to-allocated CSA, is updated with the observed figure 

of 613 MT. CSA allocation for 2011 – 482 MT – is added. Expended CSA for 2011 is 

projected using the 70 percent ratio, thus projecting an expenditure of 337 MT in 2011.

 

1 Report of the 22nd Meeting of the Parties available at: 

http://ozone.unep.org/Meeting_Documents/mop/22mop/MOP-22-9E.pdf

memorandum
2

Table 1: Annual CSA Allocations and Expenditures

Year Allocated CSA 

(MT)

Expended CSA 

(MT)a

Expended CSA to 

Allocated CSA

2006 1,136 784 69%

2007 1,915 922 48%

2008 1,730 1,047 61%

2009 1,919 1,127b 59%

2010 1,028 613 60%

2011 482 337 (Projected) 70% (Projected)

a) Source: Methyl Bromide Accounting Frameworks, 2006, 2007, 2008, and 2009. Available at: 

http://www.regulations.gov/search/Regs/home.html#docketDetail?R=EPA-HQ-OAR-2009-0351

b) According to the accounting framework, 1,135 MT of CSAs were used. Reports received after the 

Framework was submitted to UNEP indicate that 1,127 MT were used.

3) Annual estimates of methyl bromide used for non-critical purposes are updated for 2010 

and added for 2011 (Table 2). The 2010 amount, which was previously projected based 

on historical data, is updated with the actual amount used (647 MT). Use in 2011 is 

projected as 773 MT, using an un-weighted average of use in the preceding five years.

Table 2: Annual Non-Critical Use of Pre-Phaseout Inventory

Year Non-Critical Uses 

(MT)

2006 1,249

2007 561

2008 1,139

2009 267

2010 647

2011 773 (Projected)

Source: Methyl Bromide Accounting Frameworks, 2006, 2007, 2008, and 2009. Available at: 

http://www.regulations.gov/search/Regs/home.html#docketDetail?R=EPA-HQ-OAR-2009-0351

4) Based on the updates discussed in 2) and 3), the projection of pre-phaseout inventory of 

methyl bromide is updated from January 1, 2011 to January 1, 2012 (Table 3).

Table 3: Projected Methyl Bromide Pre-Phaseout Inventory on January 1, 2012

Projection Amount (MT)

Pre-Phaseout Inventory (January 1, 2010) 3,063

Total Draw Down 2,370

CSAs expended in 2010 613

Non-critical uses in 2010 647

CSAs likely to have been expended in 2011 337

Non-critical uses in 2011 773

Pre-Phaseout Inventory (January 1, 2012) 693

5) Quarterly production of critical use methyl bromide in the United States is added for 

2009 and 2010.
3

The following assumptions are retained from the previous analysis: 

1) Foreign production of methyl bromide would be sufficient to meet U.S. critical use needs 

(as well as the rest of worldwide demand) should U.S. methyl bromide production be shut 

down. 

2) Given the availability and capacity of methyl bromide shipping containers and shipping 

logistics, it would take 15 weeks for the first shipment of methyl bromide to reach the 

United States following a domestic production failure.

Using these assumptions and updated data and adopting the method used for the previous 

analysis, we update the estimate of necessary domestic methyl bromide inventories during the 

15-week period in which the U.S. would be without newly produced or imported methyl 

bromide, in the event of a major loss of domestic production capacity. We use the data on 

seasonal production of critical use methyl bromide from 2005 to 2010 to calculate the average 

proportion of methyl bromide produced per week in each quarter. The average proportion of 

methyl bromide produced per week in each quarter is multiplied by the allocated amount of

critical use methyl bromide consumption in the U.S. in 2012 (1,023 MT) and 15 weeks to 

compute the average 15-week demand for methyl bromide in 2012.

Depending on the time of year in which a disruption occurs, domestic inventory requirements are 

expected to fall between 105 and 429 MT. If a supply disruption occurs in the fourth quarter of 

the year, the inventory requirement is expected to be at the lower end of this range. If the 

disruption occurs in the first quarter, the inventory requirement is expected to be at the higher 

end of the range. For a disruption during the second or third quarters, the required inventories 

would fall between the two extremes. Using the updated domestic consumption figure of 1,023 

MT and the pre-phaseout inventory projection in Table 3, we express this range as a function of 

the two extremes (Table 4).

Table 4: Domestic Methyl Bromide Inventory Requirements

Absolute Amount Percent of 2012 

Demand

Percent of PrePhaseout Inventory 

Remaining in 2012

Domestic methyl bromide 

inventory requirement 105 - 429 MT 10 - 42 % 15 - 62 %