Risk Of Explosion Caused By Welding Or Soldering Work On Closed Air Conditioning System. Risk Of Poisoning Caused By Inhaling Overheated Refrigerant Vapors Risk Of Injury To Skin And Eyes Caused By Contact With Liquid Refrigerant. - AS83.00-Z-0001-01A

Model All (4xWD, CAR, Heavy transporter, Light transporter, smart) 

Never perform welding work on or near a closed air conditioning system. No smoking or open flames. Wear safety glasses and protective gloves. Work only in well ventilated areas. Carry out repair work on the air conditioning system circuit only after the system has been drained. 

Potential risks 

Risk of explosion 

In closed air conditioning systems (filled or emptied), high pressure can build up due to heating which can cause the system to burst. For this reason, all welding and soldering work  on or near closed air conditioning systems is prohibited.

Ignitable mixtures may form in combination with refrigerant vapors.

Risk of poisoning 

Refrigerant can break down when overheated. The resulting substances are toxic and should never be inhaled. Avoid contact with skin.

Risk of injury 

Refrigerant vapors are heavier than air; this means that escaping gases pose a risk of suffocation for anyone in a work pit beneath the vehicle.

When the air conditioning system is in operation, high operating temperatures may build up in the high-pressure lines.

Contact with liquid refrigerant may cause frostbite-like damage to the skin (due to undercooling).

Safety instructions/precautions 

• All welding and soldering work  on or near closed air conditioning systems is prohibited.
• Never smoke when working with refrigerant, never expose refrigerant to open flames! Keep away from ignition sources.
• A pungent odor  can indicate overheated refrigerant - these vapors must not be inhaled. Immediately vacate and thoroughly ventilate closed rooms. The workshop area should be ventilated with at least 1 full exchange of air per hour and the work pits ventilated with at least 3 full exchanges of air per hour.
• Radiant heaters must not be operated.
• Refrigerant supplies must be stored according to specifications.
• Only suitable air conditioning service units are to be used. These are to be stored according to specifications.
• All refrigerant must be evacuated from the entire system prior to doing any repair work  on the air conditioning circuit or components.
• In order to protect the workshop personnel and the earth's atmosphere, evacuation of refrigerant directly into the surroundings is prohibited.
• Suitable evacuation, treatment and charging devices equipped with integral disposal and treatment facilities must be used for evacuating refrigerant.
• Even after the system has been evacuated, residual pressure may still be present when loosening plug connections of the air conditioning system. Therefore, loosen the plug connections carefully, so that the pressure can dissipate slowly.
• Avoid all contact with liquid refrigerant. When working with refrigerants, be sure to wear protective goggles, suitable protective gloves and long-sleeved work clothes.

First-aid measures 

• After contact with eyes, immediately rinse with plenty of running water and consult a physician.
• After skin contact, warm frostbite injuries with water and consult a physician immediately.
• After inhaling highly concentrated refrigerant vapors, immediately take the affected person out into the fresh air and keep him/her calm. If his/her breathing is shallow, or the individual has stopped breathing altogether, tilt the head back and administer artificial resuscitation. Request an emergency physician.
• After swallowing, consult a physician immediately.