The best bet for protective masks are what are referred to as "N95 respirators," a commonly used term in Canada that refers to NIOSH-certified, disposable, particulate-filtering, half-facepiece respirators.
Not all high-quality masks are labeled N95. Health Canada said masks should offer protection equivalent to N95 to be considered effective. Such masks should:
- Filter particles one micron in size or smaller.
- Have a 95 per cent filter efficiency.
- Provide a tight facial seal (less than 10% leak).
CBC News Marketplace tested three types of N95 masks in the wake of the SARS outbreak in 2003. Each filtered out between 97 per cent and 99.7 per cent of all the virus-like particles.