Engineering Safety Basics

Safety is the paramount directive in engineering. A design that functions perfectly but endangers human life is a failed design. Before examining specific safety domains, engineers must understand the fundamental terminology of safety.

Hazard vs. Risk

These two words are often used interchangeably in everyday conversation, but in engineering, they represent entirely different concepts:

• Hazard: A potential source of harm or adverse health effect. It is a physical property or condition.
  • Examples: High-voltage electricity is a hazard. A pool of toxic acid is a hazard. Gravity (if you are standing on a roof) is a hazard.
• Risk: The likelihood that a hazard will actually cause harm, combined with the severity of that harm.
  • Example: A high-voltage cable buried safely underground in a concrete vault represents a high hazard but a low risk. The exact same cable lying bare across a busy sidewalk represents a high hazard and a very high risk.
  • Engineering Goal: Engineers generally cannot eliminate physical hazards (electricity must be high voltage to travel long distances). Instead, they design systems to minimize the risk posed by those hazards.

Safety Terminology

• PPE (Personal Protective Equipment): Gear worn by workers to minimize exposure to hazards (e.g., hard hats, safety glasses, steel-toed boots). Crucially, PPE is the absolute last line of defense, not the primary safety strategy.
• Warning vs. Caution: In manuals and on equipment labels, these indicate different levels of danger.
  • Warning: Indicates a hazardous situation which, if not avoided, could result in death or serious injury.
  • Caution: Indicates a hazardous situation which, if not avoided, could result in minor or moderate injury or damage to equipment.