Risk and Safety Statements

Risk and Safety Statements, also known as R/S statements, R/S numbers, R/S phrases, and R/S sentences, is a system of hazard codes and phrases for labeling dangerous chemicals and compounds. The R/S statement of a compound consists of a risk part (R) and a safety part (S), each followed by a combination of numbers. Each number corresponds to a phrase. The phrase corresponding to the letter/number combination has the same meaning in different languages—see 'in other languages' on the left.

Example
The R/S statement code for fuming hydrochloric acid (37%):
 * R: 34-37 S: 26-36-45.

The corresponding English language phrases:
 * Risks
 * R: 34 Causes burns
 * R: 37 Irritating to the respiratory system.
 * Safety
 * S: 26 In case of contact with eyes, rinse immediately with plenty of water and seek medical advice.
 * S: 36 Wear suitable protective clothing.
 * S: 45 In case of accident or if you feel unwell, seek medical advice immediately (show label where possible).

Dashes separate the phrase numbers. They are not to be confused with range indicators.
 * Example: R: 34-37 Causes burns, irritating to the respiratory system.

Slashes indicate fixed combinations of single phrases.
 * Example: R: 36/37/38 Irritating to eyes, respiratory system and skin.

More detailed hazard and safety information can be found in the material safety data sheets (MSDS) of a compound.