Breathalyzer mouthpieces and how to match them to your tester

Makers use a handful of designs, and knowing which one your tester takes saves a wasted order.

• Straight blow tubes. The most common type, a short plastic tube that slides onto the breath inlet. Some are sold as washable and reusable, others as single-use.
• One-way or non-return valve mouthpieces. A small valve lets breath flow into the device but stops the user from drawing air back through the tube. AlcoMate and Draeger both offer this type for their devices.
• Built in fold out mouthpieces. Some keychain testers have a hinged mouthpiece attached to the body, with slip on covers for sharing.
• Passive or mouthpiece free sampling. Some professional devices can sample the air near a person without any mouthpiece, which is an enforcement feature rather than a replacement for a proper test.
• Drinking straws. Public wall units in bars and venues often take ordinary straws instead of a dedicated tube.

BACtrack sells separate mouthpiece families for its keychain models, its C-Series smartphone testers, the S35, the Mobile and its professional range. The professional mouthpieces come in packs from 10 to 1,000, individually wrapped and made of FDA compliant food grade plastic, and the maker says they are removable, washable and reusable: drop them into soapy water, rinse and let them air dry. BACtrack also states that mouthpieces do not affect accuracy or operation, and that their purpose is to make testing other people easy and safe. The maker does not mention a one-way valve on any of its mouthpieces. If you own a BACtrack Mobile, our BACtrack Mobile Pro review notes that it ships with 3 mouthpieces and that packs of 10, 20 and 50 are sold separately. The BACtrack Go keychain breathalyzer has a fold out mouthpiece with 3 spare covers in the box.

AlcoMate standard mouthpieces carry the maker's one-way flow design, and the device record filed for them states they are for single use. The maker advises using genuine AlcoMate mouthpieces for the best results and lists them as fitting the whole AlcoMate range. The AlcoMate Revo ships with 5 disposable mouthpieces, so a pack is a sensible add on if several people will use one tester.

Professional instruments use proprietary parts bought through the maker or its distributors rather than general retail. The Draeger Alcotest 5820 takes slide and click mouthpieces that are individually packaged, with a tamper proof air outlet and a spacer that keeps lips away from the housing and also ejects the used tube; they come with or without a non-return valve. Lifeloc offers EasyTab mouthpieces for its FC series, L Series and L Series Passive mouthpieces, the LifeGuard disposable mouthpiece and calibration mouthpieces for wet bath calibration. For DOT confirmation tests under 49 CFR Part 40, the technician must open a new individually wrapped or sealed mouthpiece in view of the employee, which is why workplace programs keep sealed stock on hand. Our guide to dot breath alcohol testing explains the rest of that procedure, and the professional breathalyzer category covers the devices themselves.

A mouthpiece belongs to one person for one session. If a tester is shared in a household or a small team, give each person their own tube, or use single-use parts that go in the bin after each test. Washable types should be cleaned the way the maker describes and dried fully before storage, because a damp tube can trap residue. Never blow through a cracked or bent mouthpiece, since a poor seal can disturb the sample. Keep spares in a closed bag so they stay clean, and store them away from heat in the same place as the tester.

Start with the exact model name printed on your tester or in its manual, then match it to the maker's own compatibility list rather than to a photo, since many tubes look alike. Buy from the device maker where you can, because both BACtrack and AlcoMate list compatibility by model. Pick pack size by how many people test: a personal user may need only a small pack, while a business that screens staff needs a larger stock of individually wrapped parts. If your device is one of the older models, such as the legacy unit in our AlcoHAWK Pro review, check whether parts are still offered before relying on it. Choosing a tester for the first time is easier with the best breathalyzer ranking.