Design for Safety

1. Design for Safety Note: Oral Progress Reports due on Thursday • Injury • Hazards • Conditional Circumstances • Legal Responsibilities • Guidelines for Safe Products/systems • Safety Hierarchy • Safe Design Principles • Summary

2. Injury • Injury to user, products liability • Injury to consumer /society • Injury to production worker (e.g. OSHA) • damage to personal property • Damage to real property

3. Hazards def – a source of danger which has the potential to injure people or damage property or the environment 1. Entrapment – pinch, crush 2. Contact – heat, sharp edges, electric 3. Impact – hammer, robot arm 4. Ejection – grinder sparks, saw dust 5. Entanglement – hair, clothing 6. Noise & Vibration – hearing loss, HAVS

4. Conditional Circumstances 1) hazard is inherent during normal use 2) hazard originates from a component failure 3) hazard caused by user misuse 4) hazard exists during normal maintenance 5) hazard created by improper maintenance 6) hazard stems from lack of maintenance

5. Legal Responsibilities Products Liability - Civil Actions, Criminal Actions Plaintiffs attorney will try to prove that the company or its employees failed to: • perform appropriate analyses. • comply with published standards. • make use of state-of-the-art technology, due to ignorance. • include reasonable safety features or devices. • take into account how the user might misuse the product. • consider hidden dangers that might surprise the user. • consider variations in materials, mfg processes, or effects of wear. • carry out appropriate testing, or interpret results correctly.

6. Guidelines for Safe Products/systems • Perform appropriate analyses • Comply with published standards • Use state-of-the-art technology • Include reasonable safety features or devices • Take into account how the user might misuse the product • Consider hidden dangers that might surprise the user • Consider variations in materials or manufacturing processes, or effects of wear • Carry out appropriate testing and interpret results correctly • Provide adequate warnings • Implement superior quality control • Document everything

7. Safety Hierarchy 1) Eliminate the hazard– This is a pro-active approach which recognizes that it is often more effective to just “design-out” the hazard. Redesigning the cover to eliminate access to the moving parts is an example. 2) Protect against the hazard– This is a passive or indirect approach which does not eliminate the hazard, but eliminates the opportunity for the user to come into contact with the hazard. Examples include machine guards, safety interlock switches, light curtains, seat belts, and locked equipment rooms. 3) Warn against the hazard- This does not eliminate the hazard or the opportunity. It is a weak remedy, but in some cases the only effective alternative. Examples include warning labels, passive barriers and alarm systems. 4) Provide training – Provide and require operating training. 5) Provide personal protection – provide the operator or user with protective clothing or protective devices such as safety glasses, non-flammable welding aprons, or rubber gloves to handle chemicals

8. Safe Design Principles • Safe-Life– Product is designed to operate for its entire predicted useful life without breakdown or malfunction. Requires the designers to identify all operating conditions, misuses and abuses of the product, and appropriate maintenance and repair schedules. 2) Fail-Safe – Product is designed such that upon failure of a component, some critical functions are still performed. Failure of the component should be discernible such that the product can be shut down safely. Example includes a boiler feed-water valve failing in the open position 3) Redundant design principle – additional product components or systems take over the principle function of the failed component or system. Examples include multi-engine airplanes, standby electric generators, dual in-line oil filters, and emergency brakes.

9. Summary Prevent Injury Hazards exist Hazards may depend on conditions Legal Responsibilities Guidelines for Safe Products/systems Safety Hierarchy – maximize our efforts Safe Design Principles Safety is no accident anonymous