The use of safety glasses when work­ing with refrigerants is so important that it is placed at the beginning of the chapter. Wear safety glasses to protect the eyes from any type of injury. 

Refrigerants assume a temperature in relation­ship to their pressures. At zero or atmospheric pressure, therefore, R-12 liquid will be about 21 degrees below zero and R-22 will be about 40 degrees below zero. If either of these refrigerants should accidentally be sprayed into the eyes, the instant freezing effect would be disastrous. If liquid refrigerant should come in contact with any part of the body, flush with water immediately. A physician should then be consulted, particularly if the eyes are involved.