Which of the following limitations is...

🔍 Key Concepts

• Gas masks/filter masks vs. self‑contained breathing apparatus (SCBA) and when each is appropriate • How canister life is actually determined (by concentration, type of gas, and breathing rate, not just a fixed clock time) • Manufacturer’s storage life vs. use life once the seal is broken

💭 Think About

• Think about whether a canister can have a single universal time limit (like 30 minutes) for all highly toxic gases, or whether this would depend on conditions. • Ask yourself if a 5‑year shelf life with an unbroken seal sounds like a guaranteed "reliable in any situation" statement, or if there are usually more conditions attached. • Consider what realistically happens once the seal is broken: is there a rigid 24‑hour rule for all canisters, or does service life depend on exposure and use?

✅ Before You Answer

• Check whether filter masks are allowed at all in immediately dangerous to life and health (IDLH) atmospheres or if another type of breathing apparatus is required. • Verify how canister service life is specified: is it a fixed time in regulations, or do manufacturers specify different limits for different gases and conditions? • Confirm whether regulations or guidance actually state an across‑the‑board discard time (like 24 hours) after opening, or if that statement sounds oversimplified.

Which of the following limitations is correct regarding gas masks, otherwise called filter masks?

A maximum of only 30 minutes of protection is afforded with a single canister when in atmospheres containing highly toxic gases.

A canister is reliable for up to 5 years from the date of manufacture, as long as the seal is unbroken.

All canisters must be discarded within 24 hours when the seal becomes broken.

All of the above.

🔍 Key Concepts

💭 Think About

✅ Before You Answer