OSHA's respiratory protection standard requires users of chemical cartridge respirators to implement a cartridge change schedule based on "objective information or data" to help prevent worker overexposure. Cartridge service life is the estimated period of time before breakthrough of a chemical for a specific cartridge. This information can be used in establishing an appropriate change schedule. 3M's Service Life Software calculates service life based on workplace conditions such as contaminant concentration. Version 2.0 handles mixtures, inorganics and more.