Means the maximum concentration of a chemical in air that is safe for the operator. In a period of 15 minutes, and has been repeated up to 4 times in 1 day each time must be at least 1 hour of each other.
Represents the maximum concentration of a chemical in the air is safe for workers. Been on for 15 minutes and get unique up to 4 times in one day at a time to be away for at least 1 hour.
Means the maximum concentration of chemicals in the air, safe for workers will be. รับในระยะ time 15 minutes and get unique not exceeding 4 times in 1 days. Each time apart with at least 1 hours.