Moldex 0103 Bitrex Face Fit Test Kit: How Many Fit Tests Per Kit?

The Moldex 0103 Bitrex face-fit testing kit is a staple for safety teams because it provides a quick pass/fail taste test that satisfies OSHA and HSE requirements. But exactly how many complete fit tests you can run before the liquid runs dry depends on whether your kit contains the legacy 2.5 ml glass ampoules or the newer 30 ml screw-cap bottles. Below you’ll find the numbers, the regulations that set the test-volume rules, and practical tips to squeeze every last test out of your Bitrex solution.

OSHA 29 CFR 1910.134 requires every tight-fitting respirator wearer to pass an approved qualitative or quantitative fit test at least once a year—and again after any big weight change, dental work or switch of mask model.

A busy safety programme can burn through solution fast, so knowing the true capacity helps you budget, schedule, and order refills before you run out.

The classic Moldex 0103 ships with six 2.5 ml sensitivity ampoules (code 0503) and six 2.5 ml test ampoules (code 0504).

Per-ampoule output: Each ampoule supports roughly 3 – 5 individual fit tests, depending on how many bulb squeezes the wearer needed during the sensitivity check.

Kit output: Six ampoules × 3–5 tests yields = 18 – 30 complete qualitative fit tests per kit.

The range is broad because OSHA’s Bitrex protocol lets the tester choose 10, 20 or 30 squeezes based on how quickly the wearer tastes the bitter aerosol Longer test runs consume more liquid, pushing you toward the lower end of the capacity scale.

To reduce glass waste, Moldex now supplies many European kits with one 30 ml sensitivity bottle and one 30 ml test bottle instead of ampoules.

Distributors quote ≈ 35 – 40 tests per 30 ml bottle, assuming standard nebuliser technique.

Because you use solution from both bottles every time, each pair delivers roughly 35 – 40 complete tests before one bottle empties first.

Functionally, a bottle set gets you about the same throughput as the high end of the old ampoule kit—but with fewer containers to open and less packaging to dispose of.

1. Count your squeezes. Stop as soon as the wearer tastes Bitrex; extra puffs waste liquid with zero safety benefit.

2. Dedicated nebulisers. Label one nebuliser for sensitivity and one for test to avoid cross-contamination, which ruins the taste threshold and forces a retest.

3. Keep ampoules upright when crushing. The Moldex instructions warn that tilting can squirt solution out and spill precious millilitres.

4. Rinse and air-dry nebulisers after each session. Dried crystals clog jets, making you squeeze harder and use more solution.

5. Store spares now. Six-packs of 2.5 ml ampoules (0503/0504) and single 30 ml bottles are inexpensive, have a long shelf-life, and prevent cancelled test days if supply chains falter.

A good rule of thumb is to order one box of 0503 sensitivity bottles and one box of 0504 test bottles for every 25–30 employees you plan to test, or one pair of 30 ml bottles for every 35–40 employees.

Always check you have spare nebuliser inserts and a working hood; both degrade over time and can skew results.

The short answer really, is No.

The 18-30 (or 35-40) test range you saw applies only to the Moldex 0103 Bitrex qualitative kit; other brands and even other Moldex kits come with different bottle sizes, ampoule counts and aerosol types, so their practical test capacity can vary from ≈18 tests (small-ampoule kits) right up to ≈150 tests (large-bottle 3M kits) depending on the packaging and the OSHA squeeze-count you follow.

All qualitative fit-tests consume one sensitivity dose and one test dose per subject, but:

• Container size: (2.5 ml ampoule vs 30 ml bottle vs 118 ml bottle) controls the total liquid on hand.

• Protocol squeezes: (10 / 20 / 30) determine how fast you empty each nebuliser.

• Agent type: (Bitrex = denatonium, saccharin, or irritant smoke) dictates whether you measure in ampoules, bottles, or tubes.
  Because each manufacturer combines those variables differently, capacity diverges.