What action is suggested if oxygen levels are found to be below the required percentage?

When oxygen levels are found to be below the required percentage, improving ventilation is the key action to take. Low oxygen levels can create an unsafe environment, which may lead to health risks for workers and impair their ability to function effectively. By increasing ventilation, fresh air can be introduced into the space, helping to restore oxygen levels to a safe range.

This action directly addresses the problem at hand and is a proactive measure that can prevent accidents or health issues. It is essential for maintaining a safe working environment, especially in enclosed or semi-enclosed spaces where oxygen depletion may occur due to various factors, such as equipment operation or chemical reactions.

Other options, such as igniting the surrounding area or conducting a safety briefing, would not resolve the immediate danger presented by low oxygen levels and could, in fact, exacerbate the risks. Starting evacuation procedures might be necessary in extreme cases or if ventilation cannot adequately address the issue, but the first response should typically focus on improving ventilation to mitigate the risk as effectively as possible.