Excavation Testing: For excavations greater than 4 feet, what is required?

• A. The atmosphere shall be tested prior to entry or when the excavation is not already occupied.
• B. No testing required.
• C. Only test if someone complains.
• D. Test after entering the excavation.

Answer: (A)

For excavations over four feet, checking the air before anyone enters is essential to prevent asphyxiation or exposure to hazardous gases. The atmosphere must be tested prior to entry and also when the space is not occupied, so you can re-check air conditions before re-entry after any shift changes or work pauses, ensuring a safe environment for workers.

This is why the correct practice is to test the atmosphere before entry or during periods when the excavation is unoccupied. Relying on no testing, waiting for a complaint, or testing only after someone has already entered does not provide the necessary protection against oxygen deficiency or flammable/toxic atmospheres.