• SkillCat Team

EPA Regulations for HVAC Technicians - Part 2

Updated: Apr 8

EPA Type 1 Chapter 1

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SNAP Substitutes


In this module, we will discuss how the SNAP program affects our use of refrigerants. We will also take a look at why SNAP considers a refrigerant acceptable or unacceptable and specific examples in each category. Skip to quiz!


SNAP Background


Recall that SNAP stands for the Significant New Alternatives Policy and it is implemented by the EPA. The SNAP program was developed to evaluate new alternatives to replace phased-out refrigerants.

New alternatives that are accepted under SNAP are less harmful to the environment. These accepted refrigerants do not deplete the ozone layer and have low global warming potentials.

The SNAP program classifies a refrigerant as either:

  • Acceptable,

  • Unacceptable, or

  • Acceptable under use conditions.

SNAP looks at the use of refrigerants in different types of appliances. For example, SNAP evaluates refrigerants for use in chillers, ice rinks, industrial AC, and many other end-uses.


For Type I, we care about the refrigerants that SNAP considers acceptable for small appliances since that is what Type I is. So this means we will look at the substitutes SNAP considers acceptable for new household refrigerators or freezers.


Note that SNAP approves substitute refrigerants for new appliances. Manufacturers of new appliances factory charge the appliances with acceptable substitute refrigerants. This means that older appliances can still contain refrigerants that is not acceptable as a substitute under SNAP.


Unacceptable Substitutes


Unacceptable substitutes generally are older refrigerants or blends including older refrigerants that are harmful to the environment.

HFC blends were used in the industry as a transition away from CFCs and HCFCs. Recall that under the Kigali Amendment of the Montreal Protocol, HFC refrigerants are also being phased out because they have high global warming potentials.


Under the SNAP program, refrigerant blends containing only HFCs are generally not acceptable as of January 2021. This means you will not see HFC or HFC blends in new refrigerators but you may see them in older ones.

An example of an HFC blend is R-404a, which is a blend of:

  • 44% HFC-125,

  • 4% HFC-134a, and

  • 52% HFC-143a

Since all three components of R-404a are HFC refrigerants, R-404a is considered an HFC blend.


This is why R-404a is designated by the SNAP program as an unacceptable substitute for use in household refrigerators and freezers. Because the EPA labels it as an unacceptable substitute, you will not see R-404a used in new household refrigerators and freezers.

As of January 20211, other unacceptable substitutes for new household refrigerators and freezers include:

  • R-407c, and

  • R-410a

Recall that both R-407c and R-410a are completely HFC blends. This is why the SNAP program considers them unacceptable substitutes. So we will not see either of these refrigerants in new household refrigerators and freezers.


Acceptable Substitutes


Acceptable substitutes are generally newer refrigerants that are:

  • Non-ozone depleting, and have

  • Low global warming potential.

Acceptable substitutes include:

  • Hydrocarbons, and

  • Certain refrigerant blends

Recall that hydrocarbons such as propane (R-290) and isobutane (R-600a) are considered natural refrigerants. They do not contain chlorine so they are non-ozone depleting. They also have a global warming potential of 3, which is very low.

For new household refrigerators and freezers, SNAP approves the use of hydrocarbons under certain use conditions. The concern with hydrocarbons is that they are highly flammable. Use conditions set by the EPA are set to deal with the risk of hydrocarbons being flammable.


The SNAP program issues the following use conditions for using hydrocarbons as a substitute:

  • The maximum charge is 2 lbs,

  • Permanent labels are needed, and

  • Pipes and service ports need to be marked red.

Hydrocarbons are used as a substitute in new household refrigeration appliances only. They are not approved for retrofitting existing appliances because of safety concerns around their high flammability.


Refrigerant blends that are acceptable substitutes generally have much lower global warming potential than the refrigerants they are replacing.


For example, R-450a is an acceptable substitute for household refrigerators and freezers under the SNAP program. R-450a is a blend of

  • 42% HFC-134a, and

  • 58% HFO-1234ze.

R-450a is an alternative to R-134a. Although R-450a contains an HFC refrigerant, it is also blended with an HFO refrigerant, which gives it a lower global warming potential than R-134a. The GWP of R-450a is 547, which is a 60% reduction from the GWP of just R-134a.


To summarize, unacceptable substitutes are generally refrigerants that have high GWP-like blends that are made of completely HFCs. Some refrigerant blends containing HFC refrigerants are considered acceptable because they have much lower global warming potentials than the refrigerants they are replacing.


Hydrocarbons are considered acceptable substitutes with use conditions, but existing systems cannot be retrofitted to use hydrocarbons. Equipment containing hydrocarbons must be marked with red to deal with the risk of their flammability.



Refrigerant Management


In this module, we will review retrofitting and discuss restrictions on using hydrocarbons in retrofit applications. We will also look at how mixed refrigerant affects appliances and talk about how to prevent the mixing of refrigerants. Skip to quiz!



Retrofit Refrigerants


Recall that retrofitting is the modification of systems components in order to use different refrigerants in the system. Generally, we retrofit systems that operated on phased out CFC or HCFC refrigerants in order to use new refrigerant blends.


For example, since R-22 is phased out, we could modify or retrofit an R-22 system to operate on a different refrigerant like R-407c. SNAP regulates what refrigerants are acceptable for retrofit, depending on the appliance’s category.

Make sure that the refrigerant you want to retrofit for is approved by SNAP as acceptable for use as a substitute in that category. For example, if we want to retrofit a household refrigerator containing R-22, we want to look for acceptable substitutes for retrofitting household refrigerators.


SNAP regulates the use of a refrigerant for retrofitting separate from new appliances. For example, SNAP can find a refrigerant acceptable as a substitute for retrofit purposes but not acceptable as a substitute for use in new appliances.


For the household refrigerators and freezers, SNAP deems R-407c:

  • Acceptable as a substitute in retrofit applications, but

  • Not acceptable as a substitute in new appliances

Alternative refrigerants that are labeled acceptable substitutes by the SNAP program may be used in existing systems. But these alternative refrigerants cannot be used without retrofitting or modifying components of the system. The system must first be modified to accommodate the alternative refrigerant.


A drop-in refrigerant is a refrigerant that can be used as a replacement for the original refrigerant without any modifications to the system. According to the EPA, there are no “drop-in” substitute refrigerants for R-22. We must retrofit a system in order to use another refrigerant in the system.


Remember that we cannot retrofit a system to operate on hydrocarbon refrigerants. This is because they are highly flammable and it would be dangerous if retrofit components failed. Hydrocarbons can only be factory charged.


Mixed Refrigerant


The thermal properties of a refrigerant allow the refrigerant to go through phase changes at specific temperatures and pressures. This needs to happen in order for the refrigerant to do its job of moving heat from one place to another.

Mixed or contaminated refrigerants can have unpredictable thermal properties. The unpredictable properties cause the compressor to operate inefficiently and can cause damage to components.

Imagine mixing diesel and regular gasoline together and then using the mixture in your car. This is essentially what is happening if we put contaminated refrigerants in our system.


Recall that refrigerant must be reclaimed to virgin specifications in order to change ownership. We need to send the refrigerant to an EPA-certified reclaimer to get the refrigerant reclaimed.


If you send mixed or contaminated refrigerant to be reclaimed, the reclaimer may either

  • Refuse to accept it, or

  • Charge you extra to try to remove contaminants from the refrigerant.

To prevent the mixing of refrigerants, we need to first check what refrigerant is contained in an appliance. If you are recovering the refrigerant, make sure that the recovery cylinder is used for the same refrigerant as what is inside the appliance.


For example, let’s say we check the appliance and see that it contains an R-22 refrigerant. We’ll need to make sure to recover the refrigerant using a recovery cylinder that is only used for R-22.

Recall that recovery cylinders can only be used for one type of refrigerant. For example, recovery cylinders previously used for R-12 cannot be used to recover R-22 refrigerant. This would contaminate the refrigerant you are recovering.


If you discover that refrigerant is mixed, you must turn it into a reclaimer to try to get it reclaimed. The reclaimer will access whether the refrigerant can be restored to virgin specifications for the refrigerant. If not, you will likely have to pay a fee for the reclaimer to destroy the refrigerant.


In this module, we looked at two refrigerant management practices: retrofitting and preventing the mixing of refrigerants. In order to use a different refrigerant in any system, the system must first be modified to operate on the new refrigerant.


We want to prevent the mixing of refrigerants because reclaimers can refuse to reclaim them or charge you extra. And mixed refrigerant can cause component failure so we don’t want that in our appliances anyway. If you discover any refrigerant is mixed, you must turn it into a reclaimer to try to reclaim it.



Question #1: Which of the following is not true?

  1. SNAP lists acceptable substitutes for phased out refrigerants for different categories of end-users

  2. SNAP is implemented by the EPA

  3. Refrigerants can be classified as unacceptable under SNAP

  4. None of these

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Answer: None of these

All of these are true so the correct answer is (4).

Question #2: The SNAP program could label Refrigerant A as an acceptable substitute for use in chiller but an unacceptable substitute for vending machines.

  1. True

  2. False

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Answer: True

This is true. The SNAP program looks at a refrigerant’s use in a particular end-use or appliance. Just because it is considered an acceptable substitute for one appliance does not make it automatically accepted as a substitute for all appliances.

Question #3: Do you expect to see R-22 listed as an acceptable substitute under the SNAP program?

  1. Yes

  2. No

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Answer: No

The purpose of SNAP is to replace the use of refrigerants like HCFCs which are harmful for the environment.

We do not expect CFCs, HCFCs, or HFCs to be acceptable substitutes under SNAP.

Since R-22 is an HCFC and it’s being phased out, we do not expect it to be an acceptable substitute. In fact, R-22 is what we will be replacing with the substitute refrigerants.

Question #4: Do you expect to see R-404a in household refrigerators and freezers?

  1. Yes

  2. No

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Answer: Yes

We expect to see R-404a in some household refrigerators.

Recall that the SNAP rule on HFC blends is effective as of January 2021. So household refrigerators and freezers manufactured before then could still contain R-404a.

We do not expect to see R-404a in new household refrigerators or freezers.

Question #5: Do you expect to see R-407c in new household refrigerators and freezers?

  1. Yes

  2. No

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Answer: No

We do not expect to see R-407c in new household refrigerators and freezers.

We may see them in household refrigerators or freezers that were manufactured before January 2021, which is when the SNAP rule on HFC blends became active.

Question #6: New household refrigerators and freezers can be factory charged with

  1. R-600a

  2. R-290

  3. Both 1 and 2

  4. None of these

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Answer: Both 1 and 2

R-600a (isobutane) and R-290 (propane) are both hydrocarbons and are acceptable as substitutes in new household refrigerators and freezers under SNAP.

Recall that small appliances, including household refrigerators and freezers, are factory charged. This means the appliances are functioning out of the box.

So new small appliances will be factory charged with the acceptable substitutes under SNAP.

Question #7: Isobutane is

  1. R-290

  2. An acceptable substitute for all household refrigerators and freezers

  3. An unacceptable substitute for new household refrigerators and freezers

  4. An acceptable substitute for all new household refrigerators and freezers

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Answer: An acceptable substitute for all new household refrigerators and freezers

Isobutane is R-600a. It is considered an acceptable substitute in new household refrigerators and freezers under the SNAP program.

It is not an acceptable substitute in all new household refrigerators and freezers because that would include older appliances. They are not acceptable substitutes for used, older appliances.

Question #8: New household refrigerators and freezers containing R-290 can contain 3 lbs of refrigerant.

  1. True

  2. False

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Answer: False

R-290 is a hydrocarbon so it is subject to use conditions.

New household refrigerators and freezers containing R-290 can only contain up to 2 lbs of refrigerant.

Question #9: We can retrofit an old appliance to operate on 2 lbs of R-600a.

  1. True

  2. False

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Answer: False

R-600a is a hydrocarbon and is subject to use conditions. Under the use conditions, we cannot retrofit old appliances to operate on hydrocarbons because they are highly flammable. Any malfunction of the modified parts will be dangerous and can cause fires or explosions.

The 2 lb maximum charge applies to new appliances only.

Question #10: Only refrigerant blends without HFCs are acceptable under the SNAP program.

  1. True

  2. False

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Answer: False

Refrigerant blends can contain HFC refrigerants and still be acceptable under the SNAP program. But they are not acceptable if they contain only HFC refrigerants.

R-450a, for example, is a blend of an HFC refrigerant and an HFO refrigerant. But it has 60% global warming potential than HFC-134a because of its HFO component.

R-450a is an acceptable substitute under the SNAP program.

Question #11: R-450a is an acceptable substitute for use in new household refrigerators and freezers under SNAP. This means new household refrigerators and freezers can be factory charged with R-450a.

  1. True

  2. False

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Answer: True

R-450a is an acceptable substitute.

New household refrigerators and freezers are factories charged with refrigerants that are acceptable substitutes under the SNAP program.


Question #12: If a household freezer contains R-22, we can retrofit it to operate on:

  1. R-12

  2. R-600a

  3. R-410a

  4. None of these

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Answer: R-410a

If a household freezer contains R-22, we can retrofit it to operate on R-410a.

When we retrofit appliances, we modify components of the system to operate on a newer refrigerant. Generally, this will be a refrigerant blend that is much more environmentally friendly.

  1. R-12 is a CFC refrigerant. This would be going backwards in terms of environmental friendliness. R-12 is actually worse than R-22 in ozone depletion

  2. Hydrocarbons are not approved for retrofit applications in the category of household refrigerators and freezers, as covered in the SNAP module

  3. Correct, this is a possible candidate for retrofit

  4. Incorrect because (c) is a possible answer


Question #13: For R-22, there are no drop-in substitutes.

  1. True

  2. False

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Answer: True

The EPA does not recognize any drop-in substitutes for systems that operate on R-22.

If we want to use a new refrigerant in an R-22 system, we must retrofit it.

Question #14: Which of the following is not correct for household refrigerators?

  1. Hydrocarbons are sometimes not approved for retrofit applications

  2. Hydrocarbons are highly flammable

  3. Hydrocarbons can only be factory charged

  4. Hydrocarbons are acceptable substitutes with use conditions

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Answer: Hydrocarbons are sometimes not approved for retrofit applications

Hydrocarbons are sometimes not approved for retrofit applications

  1. False. Hydrocarbons are not approved for retrofit applications for household refrigerators

  2. True

  3. True

  4. True

Question #15: Contaminated refrigerants can cause the appliance to:

  1. Last longer

  2. Cool less efficiently

  3. Optimize cooling

  4. None of these

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Answer: Cool less efficiency

Contaminated refrigerants in a system will decrease cooling efficiency and even cause the system to fail.

Question #16: Which of the following is true?

  1. You can only sell refrigerant that is reclaimed to virgin specifications

  2. Reclaimers can refuse to accept contaminated refrigerant

  3. Reclaimers can charge extra for processing contaminated refrigerant

  4. All of these

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Answer: All of these

All of these are true.

Question #17: If we have two HFC refrigerants, we can use the same recovery cylinder because they are the same type of refrigerant.

  1. True

  2. False

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Answer: False

We can only recover one type of refrigerant in any recovery cylinder.

Even though they may be both HFC refrigerants, they still have different properties. For example, R-32 and R-134a are both HFC refrigerants. But they must be recovered using different recovery cylinders because they still have different properties.

Question #18: If we find refrigerant that is mixed, what must we do?

  1. Destroy it

  2. Send it to the EPA to be reclaimed

  3. Send it to SkillCat to be reclaimed

  4. Send it to a certified reclaiming facility to try to reclaim it

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Answer: Send it to a certified reclaiming facility to try to reclaim it

Send it to a certified reclaiming facility to try to reclaim it

Recall that reclaiming can only be done by a certified reclaiming facility. If this is not clear, you can review our Section 608 Core module.

If the refrigerant is found to be mixed, we must send it to a reclaimer so they can try to process it to virgin specifications.


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