Industrial Health and Safety/Frequency rate & Severity Rate


Resp sir,

In my company 2 loss time accident happens and due to this 1 hrs , 30 minutes was loss. so my question is How to calculate Frequency rate and Severity rate /month. the total man hours / month is 20000.
and man works 8 hrs/ day.

If you are using the U.S. OSHA standard for loss time, the day the injury occurred is not considered a loss time. The loss or any restriction begins the following day. If the two employees spoke of in your example were out 1 hrs , 30 minutes the day of the incident but returned to work it is not counted as a loss. If you or a physician or other licensed health care professional recommended a work restriction, then day 1 does not start until the following day.

The frequency rate formula is
N 200,000 EH

N = number of injuries and illnesses, or number of lost workdays.
EH = total hours worked by all employees during a month a quarter, or fiscal year.
200,000 = base for 100 full-time equivalent workers (working 40 hours per week, 50 weeks per year).

In regard to severity rate the formula is:
N 200,000 EH

N = number of loss time workdays.
EH = total hours worked by all employees during a month a quarter, or fiscal year.
200,000 = base for 100 full-time equivalent workers (working 40 hours per week, 50 weeks per year).

Using the information you provided, providing they meet the definition I provided:

Frequency (Loss time) = 2 200,000 2000 = 200

Severity = 0 200,000 2000 =  0

I would recommend that you confirm that you meet the definition to verify the correctness.  

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Wayne Adams


I can answer general questions in the areas of HAZWOPER, respiratory protection, cave-in protection, confine space entry, DOT Fleet Safety and RCRA Hazardous Waste Management. Behavior Based Safety and organizational development are also topics in which I can provide input.


I currently work as a Corporate Health and Safety Manager for a GeoTechnical Engineering firm responsible for program development and training technical staff (engineers, geologist and biologist) in OSHA HAZWOPER radiation safety and industrial hygiene practices to ensure safety and compliance. My past experience includes working as a Senior Environmental, Health, Safety and Security Manager over an 8 State Region responsible for EHS&S development, interacting with regulatory agencies, auditing wastewater discharge permits, SPCC plans, hazardous waste management, and air emissions compliance. Additional work has included responsibility for EHS management and development of projects within the industrial and municipal sectors to include water and wastewater, microelectronics, resin regeneration, activated carbon manufacturing and hazardous waste treatment facilities throughout a 10-State Region and Western Canada.

- American Society of Safety Engineers (ASSE) - Alliance of Hazardous Materials Professionals (AHMP)

- M.S. Health and Safety, Columbia Southern University, Orange, AL. - Graduate Certificate Environmental Management, Columbia Southern University, Orange, AL. - MA, Organizational Leadership, Chapman University, Orange, California. - Graduate Certificate Human Resources, Chapman University, Orange, California. - BS, Workforce Education and Development, Southern Illinois University.

Awards and Honors
- Certified Safety Professional (CSP) - Certified Hazardous Materials Manager (CHMM) - Registered Environmental Assessor CAL-EPA - Underground Tank Site Assessor WA

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