Carbon dioxide (CO2) is gas used or produced in many industries, if not directly in the products, in cooling and refrigeration systems. Possibly because of its association with breathing (we breathe in oxygen and breathe out CO2), the toxic nature of CO2 is not always appreciated. As a result, some believe that the level of oxygen (O2) in the air is a suitable indicator of safe CO2 levels. However, while monitoring O2 concentrations protects you from asphyxiation, it can’t be relied upon to protect against CO2 poisoning. Making a link between safe levels of CO2 and safe levels of O2 can be a fatal error.
Logically, people assume the lower the gas detection alarm level, the safer the working environment, as the body will be exposed to less poisonous gas. However, this is not always the best option! If set too low, they can cause spurious alarms and unnecessary disruption. Worse still, these wolf cries have led to many incidents of detectors being ignored or switched off; with terrible results1.