Comments on U.S.EPA 40CFR82 Protection of Stratospheric Ozone;

Amendments to the Section 608 Leak Repair Requirements; Proposed 

Rule

Docket ID Number: EPA-HQ-OAR-2003-0167

Federal Register Vol. 75, No. 240, Wednesday, December 14, 2010/Proposed Rules

Definitions §82.152: Leak Rate

Leak Rate Calculation Method

 The leak rate calculation needs to have a time normalization factor to reflect the 

annual leak trigger rates.

The proposed rule replaces the existing two annual leak rate calculation methods with a 

single rolling average method that will not accurately reflect the annual leak rate in some 

cases. 

The intent of the trigger rate in the rule is to trigger repair when the magnitude of leaks 

exceed annual leak thresholds. For leaks that occur longer than a year apart or if the 

pounds of refrigerant added reflect the total additions in the past 365 days, the proposed 

formula works well. However, when leaks occur less than a year apart and the equation 

uses the number of pounds of refrigerant added since the last repair it does not reflect the 

magnitude of the annual leak rate of the system. An annual normalization factor is 

needed. For example, in the following hypothetical situation because there is no annual 

normalization built into the proposed leak rate calculation, the annual leak rate appears 

lower than actual. 

Given a 100 pound charge, and a 15 pound leak in 180 days since the last repair, the leak 

rate would be calculated using the proposed equation as:

(15 pounds leaked / 100 pound full charge) * 100% = 15% leak rate.

However, if normalized to an annual leak rate, it is:

(15 pounds leaked / 100 pound full charge) * (365 days per year / 180 days since the last 

repair) * 100% = 30% annual leak rate. 

When normalized to an annual leak rate, the leak rate increases from 15% total charge in 

six months in this example, to a 30% annual leak rate, better reflecting the magnitude of 

the leak. Therefore, the leak rate method as proposed does not reflect actual annual leak 

rates for repairs made less than one year before the leak rate was calculated. 

The leak rate calculation method should be revised to the following to accurately reflect 

annual leak rates:
(pounds of refrigerant added 

since last successful follow-up

verification test (or during the

past 365 days if that period is 

greater than one year) 365 days per year

Leak Rate = ___________________________ X ______________ X 100%

(% per year) days since last 

Pounds of refrigerant in full charge successful follow- 

 up verification test

 up to 365

Definitions §82.152: Refrigerant

 The high-global warming potential non-ODS refrigerants (substitutes for Class I

and Class II refrigerants) should be included in the rule’s definition of 

refrigerants. 

Phasing out of various ODS compounds (as required by Montreal Protocol and U.S. 

Clean Air Act Amendments of 1990) and the retrofit provisions of the current rule will 

likely cause facilities to transition into ODS substitute refrigerants such as HFCs, which, 

although not harmful to the stratospheric ozone layer, are potent greenhouse gases (GHG) 

with high global warming potential (GWP). Currently, HFCs comprise 48 percent, or 

almost half of all refrigerant greenhouse gas emissions. Therefore, to reduce GHG

emissions from refrigerant sources, it is important that HFCs and other non-ODS 

substitutes be included fully as regulated refrigerants in the proposed rule amendments. 

By12020, HFCs are expected to comprise fully 80 percent of all refrigerant GHG 

emissions, and by 2030, HFCs will comprise 99 percent of all refrigerant GHG 

emissions. Considering the U.S.EPA Endangerment Finding on GHGs, it does not seem 

reasonable to transition from one class of high-GWP compounds into another and not 

implement controls on the second class of compounds. 

Moreover, the purpose and scope (§82.150) as well as the no-venting etc. provisions of 

the current rule apply to all refrigerants including the ODS substitute refrigerants; 

therefore these refrigerants should also be subject to the required practices such as leak 

repair, retrofit and retirement, and recordkeeping requirements of the rule.

Required Practices §82.156(i): Repair of Leaks and Leak Repair Trigger Rates

Repair of Leaks at Fittings (page 78568)

 All leaks should be required to be repaired irrespective of their sources. 

The proposed allowance discussed on page 78568 of the Federal Register posting that 

leaks in appliance valves, seals, gaskets, and other fittings need not be addressed during 

 

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U.S. EPA Vintaging Model estimates of CFC, HCFC, Halon, and HFCs, 2010-2030; as estimated in 2008 
leak repair should not be included in the amended rule. While it is not possible to prevent 

all leaks; valves, seals, gaskets, and other fittings can be significant leak locations 

particularly where there is a rotating or sliding shaft as in a valve or shaft seal or other 

points of motion or stress.

Definitions §82.152: Follow-up Verification Test

Required Practices §82.156(i) Follow-up Verification Test

 The requirement that the follow-up verification test be conducted no sooner than 

24 hours after the repairs are completed may be unnecessary.

The intent that the follow-up verification test be conducted after the system has returned 

to normal operating conditions is an important stipulation to ensure that the repairs will 

hold. However, based on industry input, many systems are able to return to normal 

operating conditions much sooner than 24 hours. Therefore the intent of the requirement 

can be met in some cases during the same service repair visit, making the mandatory 24-

hour waiting time not necessary.

Definitions §82.152: Retire (new definition)

 The intent of the EPA is somewhat unclear; while repairs are at the component 

level, if a repair is unsuccessful the retirement requirement is that the entire 

appliance must be scrapped even if all but a small component is leak tight and 

functions well. 

The requirement that retire means that an entire appliance must be removed from service 

is likely to cause unnecessary expense and time when removal from service of a specific 

component that has proven to be unrepairable would likely serve the same function. 

Retire would be better defined as “the permanent removal from service of a refrigeration 

system, or component, rendering it unfit for use by the current or any future owner or 

operator”.

Contact:

Pamela Gupta, Greenhouse Gas Reduction Strategy Section Manager, 

(916) 327-0604, pgupta@arb.ca.gov

Ken Bowers

(919)323-1510, kbowers@arb.ca.gov

http://www.arb.ca.gov/cc/reftrack/reftrack.htm