10 free STS practice questions in the real exam format, covering the official content areas, with an explanation for every answer.
STS Practice Test 3Tutor mode
Question 1 of 10
Basic Industrial Hygiene
A custodian tells the shift lead that the restroom cleaner "isn't strong enough" and plans to add bleach to a bucket of an ammonia-based glass cleaner. What hazard should the lead recognize?