What is a basic requirement when using a half mask purifying respirator?

A basic requirement when using a half mask purifying respirator is that every worker must be fit tested for the mask. Fit testing is crucial because it ensures that the respirator forms a proper seal against the user's face. Without a proper fit, the respirator may not provide the expected level of protection, allowing contaminants to enter through gaps. This is especially important for half masks, which rely heavily on a secure seal to filter out harmful particles and provide adequate respiratory protection.

Using a respirator without fit testing can significantly compromise its effectiveness. Employers are typically required to perform fit testing to confirm the correct size and model of the respirator for each individual worker, ensuring their safety in environments where respiratory hazards are present. This requirement aligns with safety regulations and standards in occupational health.