On the basis of the World Health Organization WHO the acceptable exposure limit and time of CO is 9 ppm for 8 h and 26 ppm for 1 h

According to the World Health Organization (WHO), the acceptable exposure limit for carbon monoxide (CO) is 9 parts per million (ppm) for an 8-hour period. This means that individuals can be exposed to a maximum concentration of 9 ppm of CO in the air for up to 8 hours without experiencing adverse health effects.

In addition, the WHO also states that a higher concentration of CO, up to 26 ppm, is acceptable for a shorter duration of 1 hour. This means that individuals can be exposed to a maximum concentration of 26 ppm of CO in the air for up to 1 hour without experiencing adverse health effects.

It is important to note that these exposure limits are based on the current scientific understanding of the health effects of CO. Prolonged or higher exposure to CO can have serious health consequences, including carbon monoxide poisoning, which can be fatal. Therefore, it is crucial to ensure proper ventilation and minimize CO exposure to maintain a safe and healthy environment