Which of the following is NOT true regarding dust masks?

The correct answer is that dust masks do not provide protection from vapors. Dust masks are primarily created to filter out particulate matter, such as dust and larger airborne particles, thereby reducing the amount of inhaled debris. They are not equipped to filter out chemical vapors or gases; for such situations, specialized masks, such as respirators, are required. By design, dust masks focus on protecting the wearer from solid particles rather than harmful vapors, which can include fumes from various substances commonly encountered in beauty and nail salons.

The other statements highlight the functionalities of dust masks correctly; they do indeed prevent excessive inhalation of dust, are meant to be worn over the nose, and also cover the mouth. Each of these features underscores the purpose of dust masks in situations where particulate exposure is a concern, making them suitable for use in dusty environments.