Chapter 1: Atmosphere 🔒

Phrase 1: Oxygen

Phrase 2: Low oxygen

Phrase 3: Low oxygen atmosphere

Chapter 2: Rescue 🔒

Phrase 1: Rescue

Phrase 2: Rescue equipment

Phrase 3: Where is your rescue equipment?

Chapter 3: Gas meters 🔒

Phrase 1: Gas meter

Phrase 2: Calibrate

Phrase 3: Is your gas meter calibrated?

Bonus Chapter: Permit 🔒

Phrase 1: Permit

Phrase 2: confined space

Phrase 3: confined space permit