Nitric Acid Spill in a Kota College Laboratory
At a government college laboratory in Kota, you are the attendant on duty at 11:05 a.m. A 500 mL reagent bottle of concentrated nitric acid slips from a tray and cracks on the bench inside the fume hood. About 150 mL spreads across the bench and drips onto the floor. A 1 L plastic bottle of acetone stands 30 cm away, and a bag of sawdust for spill control is on the shelf. Two students in open sandals are working at the next bench. The fume hood fan is running, but the laboratory has only one acid spill kit, a box of sodium bicarbonate, and no eyewash station inside the room; the nearest eyewash is in the corridor 20 m away. The lab in-charge has stepped out and will return in 15 minutes. State what you would do first and why.
1. List the immediate actions you would take in the first three minutes, in order, and explain why sawdust and paper towels must not be used on this spill.
Read the worked answer
Order of action:
- Stop work and move the two students away from the bench; do not let anyone walk through the drip.
- Alert the nearest staff member and call the lab in-charge; if acid has touched skin, start flushing at once.
- Put on nitrile gloves, goggles, and apron; keep the fume hood running.
- If it can be done without crossing the spill, cap or move the acetone bottle away. Nitric acid is a strong oxidizer and acetone is flammable.
- Contain the spill from the outside inward with the acid spill kit or inert absorbent. Use sodium bicarbonate only in small amounts and watch for heat and fizzing.
- Barricade the area and ventilate.
Sawdust and paper towels are organic materials. Concentrated nitric acid can react violently with organic matter, and paper towels also spread the spill. Do not wash the acid into the drain.
2. How would you manage the neutralized waste and the incident record before the lab in-charge returns? Include what should not go down the sink.
Read the worked answer
Collect the neutralized residue and contaminated absorbent in a clean, labelled HDPE container. Do not put it down the sink. After the reaction has stopped, check the pH with narrow-range paper, then label the container with the chemical name, approximate volume, date, and your initials. Store it in the acid-waste cabinet or the designated temporary area.
Record in the incident log: time, location, chemical and volume, people exposed, PPE used, actions taken, and who was informed. Leave a short note for the lab in-charge. If the spill kit is used up, list it for replacement.
3. If one student splashes dilute acid on the forearm, what first-aid and reporting steps follow?
Read the worked answer
Flush the forearm with running water for at least 15 minutes. Remove any contaminated watch or clothing while flushing. Do not rub the skin or apply sodium bicarbonate paste to it.
If there is blistering, pain, or any chance the splash reached the eyes, send for medical help and continue flushing the eyes with the eyewash for 15 minutes. Report to the lab in-charge and record the incident. The student should not return to the bench until cleared.