OSHA HAZWOPER 40-Hour — All Questions

On a hazardous waste site, why does the buddy system require workers in the exclusion zone to operate in pairs?

• a.To share a single respirator between two people
• b.So each can watch the other and summon help if something goes wrong✓
• c.To reduce the number of air monitors needed
• d.To let one worker rest while the other works

The buddy system pairs workers so each keeps watch over the other's condition, checks PPE, and can quickly get help or begin rescue if a partner is overcome or injured. It provides a second set of eyes in an environment where a problem can escalate fast. Buddies stay within sight or communication range at all times.

A site is divided into three work zones. Which zone is the contaminated area where the actual hazardous work takes place?

• a.The exclusion zone✓
• b.The support zone
• c.The parking area
• d.The contamination reduction zone

The exclusion zone (hot zone) is the contaminated area where hazardous operations occur and full PPE is required. Surrounding it, the contamination reduction zone (warm zone) holds the decon line, and the support zone (cold zone) is the clean area for command and staging. Clear zone boundaries keep contamination from spreading outward.

Before entry into a permit-required confined space suspected of containing vapors, which engineering control is commonly used to make the atmosphere safer?

• a.Removing all lighting
• b.Sealing every opening
• c.Ventilating the space to control the atmosphere✓
• d.Increasing the work pace

Mechanical ventilation moves fresh air through a confined space to dilute or remove hazardous vapors and to maintain adequate oxygen, and it is paired with atmospheric testing before and during entry. Ventilation is an engineering control, which is preferred over relying on PPE alone. Confined-space entry also requires an attendant and a rescue plan.

A small liquid chemical spill occurs during drum handling. Which is a sound first-response spill-control practice for a trained worker?

• a.Wash it into the nearest storm drain
• b.Ignore it if it is under a gallon
• c.Cover it with dry paper and leave the area
• d.Contain the spill and use compatible absorbent to prevent spread✓

Good spill control confines the material with barriers or absorbents so it cannot reach drains, soil, or waterways, using absorbent that is chemically compatible with the spilled substance. Only workers trained and equipped for the hazard should respond, and larger or unknown spills trigger the emergency response plan. Never flush chemicals to a storm drain.