Environmental and Safety Practices

Copyright © 2014 Delmar, Cengage Learning

Environmental and Safety Practices

Instructor Name: (Your Name)

2CHAPTER


Learning Objectives

• Describe the effects of CFCs on the world’s ozone layer.

• Explain the Clean Air Act.

• Identify the pros and cons of CFCs, HCFCs, and HFCs.

• Work safely with mobile air-conditioning and refrigeration equipment.


Learning Objectives (continued)

• Explain the differences between virgin, recycled, and recovered refrigerant.

• Explain the greenhouse effect and its impact on our environment.

• List the greenhouse gases.

• Explain the differences between disposable and refillable refrigeration containers.


Learning Objectives (continued)

• Discuss the rationale for alternate refrigerants.

• Understand the health hazards of working with refrigerants.

• Explain how refrigerants may produce poisonous gases.

• Learn to how handle refrigerant containers safely.

• Understand general workplace precautions for working with refrigerants.


Introduction

• As of January 1, 1993, any person repairing or servicing motor vehicle air conditioners must certify to the Environmental Protection Agency (EPA) that they have acquired and are properly using approved equipment.

• Each technician authorized to use such equipment must be properly trained and certified under Section 609 of the Clean Air Act.


System Overview

• This chapter serves as a guide for technicians working in the air-conditioning and mobile-refrigeration trades.

• It outlines some of the safe handling and environmental concerns for working with today’s refrigerants.

• You will also learn about the EPA’s penalty for undocumented refrigerant gas usage as it relates to ozone depleting substances.


CAUTION

This chapter by no means exempts a technician from getting proper certification or licensing, as mandated by the EPA.


Stratospheric Ozone Depletion

• The ozone layer is located in the stratosphere, high above the earth’s surface (Figure 2-1).

• The ozone layer is formed by ultraviolet (UV) light from the sun acting on oxygen molecules.

• The ozone layer is often referred to as a protective layer because it absorbs and scatters ultraviolet light from the sun, preventing some of the harmful ultraviolet light from reaching the earth’s surface.


Stratospheric Ozone Depletion (continued)

Figure 2-1. Location of the stratosphere, far above the earth’s surface.



• Chlorofluorocarbons (CFCs) gradually float up to the stratosphere, where the chlorine reacts with the ozone, causing it to change back into oxygen (Figure 2-2).

• When the ozone layer decomposes, more UV radiation penetrates to the earth’s surface

(Figure 2-3).• Stratospheric ozone depletion is a global

concern, and it will take the cooperation of many nations to bring this process under control.



Figure 2-2. CFC molecules gradually float up to the stratosphere where they damage the ozone layer.



Figure 2-3. How chlorofluorocarbons (CFCs) destroy the ozone layer.



The health and environmental concerns caused by the breakdown of the ozone layer include:• Increase in skin cancers• Suppression of the human immune response

system• Increase in cataracts• Damage to crops• Damage to aquatic organisms• Increase in global warming


The Montreal Protocol• The Montreal Protocol is a response to the global nature

of ozone depletion.• On September 16, 1987, in Montreal, 24 nations and the

European Economic Community (EEC) signed the Montreal Protocol on substances that deplete the ozone layer.

• Most of the nations that are major producers and consumers of CFCs and halon signed the agreement.

• On August 1, 1988, the EPA put this agreement into regulations for the United States (Figure 2-4).


The Montreal Protocol (continued)

Figure 2-4. The ozone depletion process.


The Clean Air Act

• The Clean Air Act directs the EPA to establish regulations to prevent the release of ozone-depleting substances.

• Sections 608 and 609 deal with ozone depletion.

• Section 608 pertains to stationary air-conditioning equipment, mobile-refrigeration equipment, and air-conditioning equipment that uses R-22.


The Clean Air Act (continued)

• Section 609 deals with the mobile motor vehicle open-driven air-conditioning industry.

• The sale of refrigerant containers weighing less than 20 pounds is restricted to technicians certified in Section 609 (Figure 2-5).

• Technicians working with HFC-134a mobile vehicle air conditioning must be trained and certified by an EPA-approved organization.

• Technicians already certified to handle CFC-12 are not required to recertify to work with HFC-134a.


The Clean Air Act (continued)

Figure 2-5. One-pound disposable refrigerant can.


EPA Penalties• EPA penalty policies are based on the U.S.

Clean Air Act and its international counterparts.

• Noncompliance could result in fines of up to $25,000 a day, per violation.

• Refrigerant leaks not fixed within 30 days are subject to a $32,500 fine per day, per unit.

• Purchasing used or imported refrigerant gas calls for fines of $300,000 per 30-pound cylinder of refrigerant gas.


Greenhouse Effect• The greenhouse effect is a naturally-

occurring process that helps to heat the earth’s surface and atmosphere.

• The earth absorbs incoming solar radiation and then cools by emitting long-wavelength infrared radiation.

• This radiation is absorbed by greenhouse gases, thereby preventing the heat from escaping.


Greenhouse Effect (continued)

• The increase in greenhouse gases may increase average global temperature.

• In the last few centuries, human activity has directly or indirectly caused the concentration of the major greenhouse gases to increase.

• Scientists predict that the greenhouse effect will cause the planet to become warmer.


Greenhouse Gases

Some of the major greenhouse gases and their sources are:• CO2 burning of carbon-based fuels• CH4 anaerobic bacteria in rice fields, cows,

and sewage• N2O fossil fuels and fertilizer• CFCs refrigeration and spray cans• Methane (CH4) directly related to food

production and population growth


Greenhouse Gases (continued)

Figure 2-6. The greenhouse effect.


Refrigerants• Most refrigerants in use today are compounds

containing carbon, fluorine, usually chlorine, and sometimes hydrogen, bromine, or iodine.

• Refrigerants in vehicle air-conditioning systems may be referred to as CFCs, HCFCs, or HFCs.– CFC refrigerants contain chlorine, fluorine, and

carbon.

– HCFC refrigerants contain hydrogen, chlorine, fluorine, and carbon.

– HFC refrigerants contain hydrogen, fluorine, and carbon.


CFCs

• Because CFCs contain no hydrogen, they are chemically very stable—even if released into the atmosphere.

• CFCs contain chlorine, which is very damaging to the ozone layer.

• These two characteristics give CFC refrigerants a high ozone-depletion potential, or ODP.

• The manufacture of these refrigerants was discontinued as of January 1, 1996.


HCFCs• Hydrochlorofluorocarbons (HCFCs)

refrigerants contain chlorine, which is damaging to the ozone layer.

• These refrigerants have a lower ozone-depletion potential (ODP).

• HCFC-22, or R-22, is used extensively in commercial air conditioning, transport refrigeration equipment, home air conditioners, refrigerators, freezers, and dehumidifiers.

• New equipment today will not work with R-22.


HFCs• Hydrofluorocarbon (HFC) refrigerants have

largely replaced CFC-12 in the automotive field.

• These refrigerants contain no chlorine and have an ozone-depletion potential of zero.

• These refrigerants, however, are considered greenhouse gases.

• The refrigerant used in most automotive and truck trailer applications to replace CFC-12 is HFC-134a.

• The truck trailer industry also uses R404A.


Alternative Refrigerants

• Considerations for any new refrigerant are chemical stability in the system, toxicity, flammability, thermal characteristics, efficiency, ease of detection in the event of leaks, environmental effects, compatibility with system materials, compatibility with lubricants, and cost.

• In general, HFC-134a has replaced R-12 in all truck/automotive applications.

• Recycling and recovery of refrigerants is still required, regardless of the new refrigerant.


Alternative Refrigerants (continued)

• Changes to a system for the new refrigerant usually amount to replacement of incompatible seals and compressor lubricants.

• Lubricants typically used with CFC-12 do not mix with HFC-134a.

• Polyalkylene glycols (PAGs) mix properly with R-134a at low temperatures, but have upper temperature problems and incompatibility with aluminum bearings and polyester hermetic motor insulation.


Alternative Refrigerants (continued)

• Ester-based synthetic (POE) lubricants for HFC-134a resolve these problems, but are incompatible with existing PAG or mineral oils.

• POE oils are incompatible with as little as 1% residual oil (PAG or traditional mineral) in the system.

• In operation, HFC-134a is very similar to CFC-12.


Disposable Refrigerant Cylinders

• Disposable refrigerant cylinders are commonly used in the automotive air-conditioning market.

• These cylinders are not refillable with refrigerant or any other product.

• Refrigerant cylinders are usually color-coded to identify the type of refrigerant they contain.

• The color code for containers filled with R-134a is light blue.

• Be sure to follow EPA regulations in your area for safe legal disposal of these cylinders.


Disposable RefrigerantCylinders (continued)

• Disposable cylinders are equipped with a safety relief valve to prevent over-pressurizing of the cylinder, which can happen if the cylinder is subject to excessive heat.

• Cylinders should be stored and transported in a dry environment to prevent rusting.

• The internal pressure of a cylinder containing 1 ounce of liquid refrigerant and one that is full is the same.

• If containers are left outdoors, they will eventually deteriorate and may explode.



• Disposable refrigerant containers that are very rusty should have the contents removed and be properly discarded.

• Before disposing a cylinder, it must be completely emptied.

• This means that the cylinder should be put on a refrigerant recovery machine and the cylinder’s contents drawn into a vacuum.

• Follow EPA regulations for proper disposal of cylinders in your area (Figure 2-7).



Figure 2-7. Disposable refrigerant cylinders.


Refillable Cylinders

• Refillable refrigerant cylinders are commonly used in the air-conditioning/refrigeration industry.

• These cylinders contain the same refrigerants that are also available in disposable cylinders.

• Refillable cylinders are regulated in their design, fabrication, and testing by DOT.

• Refillable cylinders may also be marked with a color to indicate which refrigerant they contain.

• This type of container may be used with refrigerant recycling equipment.


Refillable Cylinders (continued)

• Cross contamination can become a problem if cylinders are interchanged, so the technician should clearly mark virgin, recycled (removed, filtered, and oil separated), or recovered (dirty) on the cylinder.

• Due to the rising cost of refrigerants, proper recycling and storage of the refrigerant for reuse in other equipment will save the shop owner money.

• Refillable cylinders contain a warning decal to caution the user against physical contact with or exposure to the refrigerant.



• Refillable refrigerant containers must be retested at 5-year intervals because corrosion of the cylinder exterior or damage caused by mishandling cannot always be avoided.

• The valves of these tanks should be checked occasionally, especially the relief valve.

• Check that nothing is blocking the relief valve and that no visible deterioration or damage has occurred.

• If damage is visible, empty the cylinder and have the cylinder repaired (Figure 2-8).



Figure 2-8. Refillable refrigerant cylinder.


CAUTIONNever under any circumstance use a cylinder with a faulty pressure relief valve or a cylinder with an obvious structural problem.


Cylinder Color Code

Refrigerant cylinders may be color-coded to indicate the type of refrigerant they contain.

▪ Refrigerant 12 White▪ Refrigerant 22 Green▪ Refrigerant 134a

Light Blue▪ Refrigerant 502 Light

Purple

▪ Refrigerant 401B Yellow/Brown

▪ Refrigerant 402A Light Brown

▪ Refrigerant 404A Orange


Refrigerant Safety

• Any technician working in the air-conditioning field should understand general safety considerations concerning fluorocarbon refrigerants.

• Before coming into contact with any refrigerant, a technician should understand the safety concerns for the specific product.

• Long-term health effects are not yet known.

• Manufacturers can provide specific product information for the refrigerants they produce.


Health Hazards• Technicians working with fluorocarbon

refrigerants should always wear safety goggles and non-leather work gloves.

• Shops where refrigerant work is done should be well ventilated to prevent technicians from inhaling large concentrations of refrigerants.

• Exposure time for some of the new refrigerants is lower than those of refrigerants with which technicians may already be familiar.


CAUTION

Refrigerant should NEVER come into contact with skin or eyes. Liquid refrigerant quickly evaporates when exposed to the air and will almost instantly freeze skin or eye tissue, so serious injury or blindness could result from contact with liquid refrigerant.


First Aid• A victim who has inhaled refrigerant should be removed

to a place where the air is fresh.

• If the victim is not breathing, call 911 and administer artificial respiration at once.

• If the victim experiences labored breathing, oxygen should be administered.

• The victim should avoid all stimulants/depressants, such as caffeine, tobacco, and alcohol.

• Get the patient to a doctor for continued treatment.


First Aid (continued)

• If a person’s eyes come in contact with liquid refrigerant, the eyes should be flushed with water for a minimum of 15 minutes, and get the person to a doctor immediately.

• If skin comes in contact with liquid refrigerant, it should be flushed with warm water to warm the skin gradually (Figure 2-9).


First Aid (continued)

Figure 2-9. Eye wash station.


Poisonous Gas• Most halogenated compounds decompose, producing

toxic vapor when they come in contact with high temperatures.

• If the compound contains chlorine, hydrochloric acid is formed and a small amount of phosgene gas is formed if a source of water (or oxygen) is present.

• Halogen gases are easily identified by a very sharp/sour smell.

• When these odors occur, the area should be evacuated and opened up to allow fresh air to dissipate the gas.


General WorkplacePrecautions

• Read all product labels and material safety data sheets (MSDS).

• Always work in a well-ventilated area.

• Never allow refrigerant vapors to come in contact with open flames, sparks, or hot surfaces.

• Do not weld or steam clean an air-conditioning system.

• When testing for leaks, do not mix R-134a with air.


General WorkplacePrecautions (continued)

• Do not recover or transfer refrigerant into a disposable cylinder.

• Do not transport refrigerant in the passenger compartment of a vehicle.

• Never expose refrigerant to open flames, high temperatures, or direct sunlight.

• Wear safety goggles, non-leather gloves, and suitable work clothing when working with refrigerants.

• Ensure that showers and eye wash fountains of the deluge-type are readily accessible.


Handling Refrigerant Cylinders• Keep cylinders secured in an upright position.

• Store refrigerants out of direct sunlight in a clean, dry area.

• Refrigerant cylinders should not be permitted to attain temperatures above 125F (51.6C). Do not store refrigerant containers in a vehicle.

• Keep the outlet port of the refrigerant cylinder capped and the valve hood securely screwed onto the neck of the cylinder at all times when it is not being used.


Handling Refrigerant Cylinders (continued)

• Never apply an external source of heat to a refrigerant cylinder.

• Never drop or strike a refrigerant cylinder with any object.

• Never lift a refrigerant cylinder by its valve or valve cover.

• Never try to repair the valve.• Never tamper with the safety device.• Avoid exposure to vapors through spills or leaks.



• Evacuate the area if a large refrigerant spill occurs.

• Check to ensure that the cylinder label matches the color code.

• Open cylinder valves slowly, and close after every use.

• Always ventilate the work area before using open flames.

• Avoid contact with liquid refrigerant because frostbite may occur.



• Do not attempt to refill disposable cylinders.• Do not remove or alter cylinder identification

markings.• Be careful not to cut or gouge the cylinder.• Keep cylinders away from corrosive materials and

water.• Don’t use cylinders that are extensively rusted or

otherwise deteriorated.• Never leave an empty reusable cylinder with its

valve open to the atmosphere.


Summary

• Anyone repairing or servicing motor vehicle air conditioners must be certified by the EPA.

• The ozone layer is a protective layer in the atmosphere that absorbs and scatters ultraviolet light from the sun.

• With the ozone layer decomposing, more UV radiation penetrates to the Earth’s surface.

• The Clean Air Act directs the EPA to establish regulations to prevent the release of ozone-depleting substances.


Summary (continued)

• The upsurge in greenhouse gases may increase average global temperature.

• Refrigerants referred to as CFCs contain chlorine, fluorine, and carbon.

• Refrigerants referred to as HCFCs contain hydrogen, chlorine, fluorine, and carbon.

• Refrigerants referred to as HFCs contain hydrogen, fluorine, and carbon.

• HFCs, such as R-134a, are not ozone-depleting but contribute to global warming.


Summary (continued)

• Refillable refrigerant cylinders may be used with refrigerant recycling equipment.

• Refrigerant cylinders may be color-coded to indicate the type of refrigerant they contain.

• If a person has inhaled refrigerant, he or she should be moved to an area where there is fresh air. If the person is not breathing, call 911 and start artificial respiration.

• Poisonous gas may be formed when refrigerant comes into contact with a heat source.

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Environmental and Safety Practices