Which of the following is the main precaution to take if a gas cylinder sign is present in the laboratory?

• A. Handle gas cylinders only with bare hands to avoid contamination.
• B. Leave gas cylinders uncapped when not in use.
• C. Ensure all gas cylinders are securely fastened and stored upright to prevent tipping.
• D. Always store gas cylinders near open flames for easy access.

Answer: (C)

Verified step by step guidance

1. Understand the nature of gas cylinders: They contain compressed gases under high pressure, which can be hazardous if not handled properly.
2. Recognize the main safety concern: Preventing the gas cylinder from falling or tipping over, which could cause damage to the valve or lead to dangerous leaks.
3. Identify the correct precaution: Securely fastening gas cylinders and storing them upright ensures stability and reduces the risk of accidents.
4. Eliminate unsafe practices: Handling cylinders with bare hands does not prevent contamination, leaving cylinders uncapped can cause leaks, and storing near open flames is a fire hazard.
5. Conclude that the primary safety measure is to ensure all gas cylinders are securely fastened and stored upright to maintain laboratory safety.