Engineering Safety Basics

Safety is the absolute primary directive in engineering. A design that functions perfectly but inherently endangers human life is a failed design. Before examining specific safety domains, an engineer must understand the foundational vocabulary of safety.

Hazard vs. Risk

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

• Hazard: A potential source of harm or damage. It is a physical property or condition.
  • Example: A high-voltage power line 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 power line buried safely underground in a concrete vault has high hazard but low risk. The same power line lying exposed across a busy sidewalk has high hazard and extreme risk.
  • The Engineering Goal: Engineers generally cannot eliminate physical hazards (electricity must be high voltage to travel long distances), but they design systems to minimize the risk of those hazards.

Safety Terminology

• PPE (Personal Protective Equipment): Equipment worn by a worker 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 signify different levels of danger.
  • Warning: Indicates a hazardous situation that, if not avoided, could result in death or serious injury.
  • Caution: Indicates a hazardous situation that, if not avoided, could result in minor or moderate injury, or damage to the equipment.