Industrial gas safety — identification color for oxygen cylinders According to common shop practice and standard coding followed in many regions, what is the usual identification color for an oxygen gas cylinder used in welding and cutting plants?

Introduction / Context:
Gas cylinder color coding helps prevent dangerous mix-ups in welding shops and industrial facilities. Oxygen, acetylene, LPG, nitrogen, and other gases are assigned distinctive colors for quick recognition. Although standards can vary by jurisdiction, many traditional curricula and exam syllabi reference a widely used coding in which oxygen cylinders are black (often with a white neck/shoulder in some codes).

Given Data / Assumptions:

• Setting: welding and cutting shop.
• Objective: identify the usual color associated with oxygen cylinders per commonly taught codes.
• Awareness: regional nuances may add a white shoulder; the body is frequently black.

Concept / Approach:
Color coding provides a first-line visual cue. Beyond color, cylinders should be verified by labels, valve type, and content tags. For educational questions, “black colour” is the accepted answer aligned with traditional coding schemes used in many training programs.

Step-by-Step Solution:

Verification / Alternative check:
Shop audits confirm technicians rely on both color and labeling; labels are mandatory to avoid sole reliance on paint.

Why Other Options Are Wrong:

• White, maroon, yellow, silver-red: associated with other gases or nonstandard shop markings.

Common Pitfalls:
Assuming color alone is sufficient identification; always check content labels and valve connections before use.

Final Answer: