The Definition of Prevention through Design (PtD)

Definition of Prevention through Design (PtD)

Prevention through Design (PtD) is the practice of anticipating and designing out hazards and risks at the earliest stages of a project, when facilities, tools, equipment, processes and work methods are being planned. Instead of relying on PPE and procedures after the fact, PtD builds safety into the design itself, which is where the most effective controls at the top of the hierarchy of controls, elimination and substitution, are easiest and cheapest to apply.

NIOSH launched a national PtD initiative in 2007, and ANSI/ASSP Z590.3 provides a consensus standard for applying PtD concepts. In some countries, such as the UK, Australia and EU member states, designers have legal duties to reduce risks to people who will build, use and maintain what they design.

Key Facts About Prevention through Design

• The ability to influence safety is highest early in a project and drops sharply once construction or installation begins.
• PtD considers the full life cycle: construction, operation, maintenance, decommissioning and demolition.
• Examples include permanent anchor points, ground-level valve access, quieter equipment and built-in guarding.
• Design reviews often use tools such as process hazard analysis and constructability reviews.
• PtD typically lowers long-term costs by reducing retrofits, downtime and injuries.

Example of Prevention through Design

During design of a new warehouse, the safety team asks for rooftop HVAC units to be set back from the roof edge and for a parapet wall to be raised to guardrail height. Maintenance crews will never need temporary fall protection to service the units.

How to Apply Prevention through Design

1. Involve safety, operations and maintenance people in early design reviews.
2. Identify hazards across the full life cycle of the design.
3. Prioritize elimination and substitution, then engineering controls.
4. Document design decisions and residual risks for users.
5. Feed lessons from incidents back into design standards.

Related Terms

• Hierarchy of Controls
• Engineering Controls
• Management of Change (MOC)
• Ergonomics
• ALARP

Frequently Asked Questions: Prevention through Design

Who is responsible for Prevention through Design?

Designers, engineers, architects and owners share responsibility, with input from the safety professionals and workers who will build, operate and maintain the result.

Can PtD be applied to existing facilities?

Yes. Any redesign, retrofit, equipment purchase or process change is an opportunity to design out hazards.

Is PtD required by law?

Not generally in the U.S., but some countries place legal duties on designers. Many U.S. companies require PtD reviews as part of capital projects.