Abstract: A personal breathing apparatus includes a housing having an exhaust port, at least one filter-port, and a mouth-port connecting to a mouthpiece which is held inside the user's mouth while worn. A mouthguard on the mouthpiece is claspable by the user's teeth. By design, the personal breathing apparatus is balancable at the mouthpiece, such that the portion of the apparatus outside of the user's mouth is no heavier than the portion inside the user's mouth. In this way, the apparatus can be retained only by the clenching action of the user's teeth for long periods of time with no duress to the user. No head strap or other retention fastener is required.

Abstract: A personal breathing apparatus includes a housing having an exhaust port, at least one filter-port, and a mouth-port connecting to a mouthpiece which is held inside the user's mouth while worn. A mouthguard on the mouthpiece is claspable by the user's teeth. By design, the personal breathing apparatus is balancable at the mouthpiece, such that the portion of the apparatus outside of the user's mouth is no heavier than the portion inside the user's mouth. In this way, the apparatus can be retained only by the clenching action of the user's teeth for long periods of time with no duress to the user. No head strap or other retention fastener is required.

Abstract: A personal breathing apparatus; the personal breathing apparatus includes a body having an exhaust port, a nasal-port, at least one filter-port, and a mouth-port. A nasal insert is configured to attach to the nasal-port. A mouthguard is anatomically shaped to create an air-tight seal to a user's mouth. The mouthguard is configured to attach to the mouth-port. The filter-port is designed to attach to at least one filter. At least one filter is included with the personal breathing apparatus. By design, the personal breathing apparatus is lightweight and unobtrusive. The personal breathing apparatus does not rely on an airtight seal between the apparatus and a large portion of the surface area of the users face.