HIRARC is the term used by DOSH(Department of Safety and Health) to indicate Hazard Identification, Hazard Assessment and Risk Control.
HIRADC is term used by OHSAS 18001:2007 to indicate Hazard Identification, Risk Assessment and Determine of Control.
HRA is the term used in Industrial Hygiene to indicate Health Risk Assessment — to carry out the same thing as HIRARC and HIRADC.
So What is the different? Are they the same? The purpose is the same, but the way they carry out Risk Assessment is not similar.
We cannot use simply Generic Format of HIRARC to assess Health Hazard like Chemical, Physical and Ergonomics — our assessment will not indicate the real risk.
In assessing the risk of chemical and Physical hazard for example using HRA, we need to assess the Exposure Magnitude, we need to know the Exposure level and compare it with the PEL (Permissible Exposure Limit). That is why CHRA existed, CHRA means Chemical Health Risk Assessment.
In assessing Ergonomics Hazard, we need to find out the Ergonomics Risk Factors, the body Symptom level and other things— which Ergonomist like to call it as EWA (Ergonomic Workplace Assessment).
Sometime I feel, HIRARC is created from the perspective of Safety Hazard Assessment. For Health hazard, we need to do a proper HRA whether we called it CHRA or EWA.
Lastly, HIRARC/HIRADC and HRA are similar but not the same.