Refrigerant, Handling

• Since the refrigerant R744 is a naturally occurring substance that does not fall under the Recycling and Disposal Law, it may be released into the environment and is not subject to the proof of disposal obligation that applies to chemical refrigerants. For information on handling chemical refrigerants. Refer to LAWS AND REGULATIONS (Legal Texts and Regulations).
• Refrigerant R744 has no noticeable odor, which is therefore not perceptible.
• The refrigerant is heavier than air and falls to lower lying areas such as the work pit, basements, and deep spots and displaces the breathable air and oxygen. Remaining in oxygen deprived areas is extremely dangerous.
• For example, liquid refrigerant from a leak evaporates at an ambient pressure of approximately 1 bar (14.5 psi) at approximately -78.7 °C (-109.7 °F). If the refrigerant evaporates on skin, it can cause frostbite or cryogenic burns. Delicate organs, such as the cornea and mucous membranes are especially at risk. Excessive frostbite may be life threatening.
• The specific dangers associated with the refrigerant, material data etc. can be found in the safety data sheets. Safety data sheets for refrigerant, refrigerant oil, etc. can be found in the safety data sheets.
• Refrigerant oil that may escape with the refrigerant breaks down when near a flame or when contacting a hot surface. There is a danger of becoming poisoned by the resulting toxic fumes if inhaled. A pungent odor indicates that the products of the decomposition mentioned above have already formed. Avoid inhaling these substances under all circumstances, as otherwise the respiratory system, lungs and other organs could be damaged.
• When handling refrigerant and working on the refrigerant circuit, make sure the area is well ventilated (air change at least one time each hour in the workshop area, and three times per hour in low-lying areas (for example, work pits).

• Never weld or hard/soft solder components of a filled A/C system. This also applies to welding and soldering on the vehicle, if there is a risk that it may heat up components in the A/C system. When performing paintwork repairs, the temperature in the drying booth or preheating zone must not exceed 80 °C (176 °F).
• Damaged or leaking parts of the A/C system are never to be repaired by welding or soldering them; they are always to be replaced.

Reason:

Exposure to heat increases the pressure in the system, which could cause the pressure relief valve to open.

Corrective Measure:

-- Discharge the refrigerant circuit using the A/C Service Station. Refer to WORKING WITH A/C SERVICE STATION .

Refrigerant cylinders (for example, charging cylinders of A/C Service Station) must never be overfilled, subjected to excessive heat, or exposed to direct sunlight.

Reason:

Refrigerant stretches when warmed.

Corrective Measure:

-- When filling and storing compressed-gas canisters, the applicable regulations, technical regulations and laws must be observed.

-- Canisters and equipment must never be completely filled with liquid refrigerant. Without sufficient room for expansion (gas cushion), reservoirs will rupture with devastating effects in the event of a temperature increase. Refer to PHYSICAL CHARACTERISTICS .

Refrigerant is never to be transferred to systems or reservoirs in which air is present.

Corrective Measure:

-- Evacuate systems and reservoirs before charging with refrigerant. Refer to WORKING WITH A/C SERVICE STATION .