What is the maximum mg/m^3 value used as the golden standard occupational exposure limit for carbon dioxide (CO2)?

• A. < 6000 mg/m^3
• B. < 9000 mg/m^3
• C. > 6000 mg/m^3
• D. Cannot be measured

Answer: (C)

The concept here is converting exposure limits from ppm to mg/m^3. For CO2, with a molar mass of 44 g/mol, the mg/m^3 value is roughly ppm × 44 / 24.45 ≈ ppm × 1.8 at standard conditions. The common occupational limit is about 5,000 ppm, which converts to roughly 9,000 mg/m^3. That means the maximum mg/m^3 value used as the standard is around 9,000 mg/m^3, clearly greater than 6,000 mg/m^3. So the statement that the limit is above 6,000 mg/m^3 is the best fit.