| Concentration of CO in the air | Implications of Exposure |
| 10 parts per million (ppm) | Threshold at which prolonged exposure can have adverse effects on the body and brain. This can include neuropsychological and cardiovascular issues. |
| 50 parts per million (ppm) | Safety level as specified by the Health and Safety Executive for a maximum of 30 minutes. |
| 200 PPM | Slight headache within 2-3 hours. |
| 400 PPM | Frontal headache within 1-2 hours, becoming widespread in 3 hours. |
| 800 PPM | Dizziness, nausea, convulsions within 45 minutes, insensible in 2 hours. |
Reviewed: 14/09/2023 (doc:536 V1.0). Our articles are reviewed regularly. However, any changes made to standards or legislation following the review date will not have been considered. Please note that we provide abridged, easy-to-understand guidance. To make detailed decisions about your fire safety provisions, you might require further advice or need to consult the full standards and legislation.
