California Wastewater Treatment Operator Practice Exam

Which of the following is one of the basic rules of lab work?

1. Never pipet hazardous material with your mouth, even if the pipet has been sterilized

2. Use bare hands to handle chemical samples

3. Mix different chemicals in the same waste container

4. Keep the lab door closed at all times

The correct answer is: Never pipet hazardous material with your mouth, even if the pipet has been sterilized

The first choice is correct because it highlights a fundamental safety rule in laboratory work, emphasizing the importance of avoiding direct exposure to hazardous materials. Using your mouth to pipet any substance poses a significant risk, even if the pipet appears to be sterilized, as contaminants could still be present. This practice is critical to maintaining safety in the lab and preventing harmful ingestion or exposure. The other options relate to improper practices in a laboratory setting. Using bare hands to handle chemical samples can lead to skin exposure and contamination as it overlooks the necessity of wearing protective gear such as gloves. Mixing different chemicals in the same waste container can create dangerous reactions and is contrary to established waste disposal protocols. Keeping the lab door closed at all times can help maintain a controlled environment, but it may not be practical in every situation, especially for ventilation and emergency access considerations.