DI:8.2 SAFETY

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It is natural for a machine to have hazardous parts/functions/flows.

If the risk (probability) of comming in contact is high we call this danger

Typical hazards include,

- pinch points

- crushing

- collision with moving objects

- falling from heights

- slippery surfaces

- explossion

- electric shock

- temperature/fire

- toxicity

- physical strain

When possible it is best to eliminate hazards. If this is not possible we want to reduce the risk of access (hence danger).

OSHA (Occupational Safety and Health Administration) regulates workplace procedures.

Danger can be reduced by,

- signs

- safegaurds (e.g. barriers)

- policies and procedures

- worker training

- special protective equipment (e.g. earplugs)

Typical additions to machines include,

- barrier gaurds - physical blocks to separate operators and equipment. Interlocks are used to disable the machine when the barrier is open.

- passive safety devices - for example seat belts

- active safety devices - these include

- hand pull-backs

- dead-man controls

- presence sensing devices

- maintenance safety devices - these additions (and procedures) ensure that the machine is still safe, even though the normal safety equipment is disabled.

- warnings - large warning signs, buzzers, status lights, etc. are used to promote awareness.

Note: It is important to place safety considerations at the top of the design priorities. It is so obvious that it is quite often assumed.

DI:8.2.1 Environment

Environmental considerations are a natural consideration of the design process and can be considered an extension of safety.

design factors that will impact the environment include,

- discharges/waste (gas, liquids, solids) from production processes

- energy/fuel utilization in production

- aging of the product - decay, inert, toxic, etc.

- energy/fuel efficiency in use

There are a wide variety of laws, agencies and organizations that influence manufacturing and consumer products,

OSHA (Occupational Safety and Health Administration)

EPA (Environment Protection Agency)

NIOSH (National Institute for Occupational Safety & Health)

UL (Underwriters Laboratory)

CSA (Canadian Safety Association)

DI:8.2.2 MIL-STD 882B - System Safety Program Requirements

This standard addresses the likelyhood and acceptability of hazards.

The basic tables are,