Work out cartridge service life instantly with clear inputs, formula shown and shareable results.
Cartridge life is sorbent capacity divided by the rate at which contaminant is drawn in. Converting ppm to mg/m³ uses the molar volume of 24.45 litres at 25 °C and one atmosphere, and multiplying by breathing rate gives grams per hour. A change schedule at ninety percent of calculated life provides margin for humidity and concentration variation.
Mass concentration
mg/m³ = ppm x molecular weight / 24.45
Service life
Hours = sorbent capacity g / (mg/m³ x m³ per hour / 1000)
Preliminary estimate only. Cartridge change schedules must be established using the manufacturer's breakthrough data or a validated model as part of a written respiratory protection programme.
mg/m³ = ppm x molecular weight / 24.45. Cartridge life is sorbent capacity divided by the rate at which contaminant is drawn in.
Water vapour competes for adsorption sites on the activated carbon. Above about sixty-five percent relative humidity, breakthrough time can fall by half.
This calculator takes 4 inputs: Cartridge sorbent capacity, Contaminant concentration, Molecular weight, Breathing rate. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.