Safety Layer

A system or subsystem that is considered adequate to protect against a specific hazard. The safety layer

  • is totally independent of any other protective layers
  • cannot be compromised by the failure of another safety layer Glossary 165
  • must have acceptable reliability
  • must be approved according to company policy and procedures
  • must meet proper equipment classification
  • may be a noncontrol alternative (i.e., chemical, mechanical)
  • may require diverse hardware and software packages
  • may be an administrative procedure