When using alcohol on your bike brake's rotors, it is important to consider your safety and choose an appropriate mask. Alcohol fumes can be harmful if inhaled in excessive amounts, so a mask that provides respiratory protection is recommended.
The best type of mask to use when working with alcohol or other volatile substances is a respirator with an appropriate filter. Specifically, you should use a mask that is rated for organic vapors. These masks are designed to filter out airborne particles and vapors, including alcohol fumes.
A respirator with an N95, N99, or N100 rating is a good choice. These ratings indicate the mask's filtration efficiency against particles of different sizes. However, keep in mind that these masks may not provide adequate protection against organic vapors, so it's crucial to choose a respirator specifically designed for organic vapor filtration.
Ensure that the mask fits properly and creates a tight seal around your face. Follow the manufacturer's instructions for proper usage, including how to wear, fit, and replace the filter if necessary.
Remember to work in a well-ventilated area whenever possible to further reduce the risk of inhaling alcohol fumes.