Guide to EHSQ Metrics

The best-run environmental, health,  safety and quality (EHSQ) operations employ an approach to decision making based on data and facts.

Safety and Health Metrics

Following are several key metrics for tracking the performance of safety and health programs:

• Occupational Safety and Health Administration (OSHA) Injury and Illness Incident Report and Summary
• Lost Workday Incidence Rate
• OSHA Days Away from work, Restricted work, or job Transfer injury and illness rate (DART rate)
• Person-hours worked since last lost workday incident
• Number and amount of OSHA fines
• Workers' compensation experience modifier

Environmental Metrics

Here are several key metrics for tracking the performance of environmental programs:

• Amount of hazardous waste generated;
• Toxics Release Inventory (quantity of toxic chemicals released);
• Number of notices of violations;
• Number of inspections;
• Amount or percent of materials recycled;
• Amount or percent of materials discarded;
• Amount of water used;
• Permit parameters; and
• Number or percentage of employees that have completed training or certifications.

Carbon emissions calculations. With heat-trapping gases such as carbon dioxide (CO2) and methane now subject to regulation, many businesses are increasingly concerned about their emissions of gases that contribute to global warming. The U.S. Environmental Protection Agency (EPA) has developed carbon and CO2 equivalence metrics for calculating emissions of greenhouse gases (GHGs).
Emissions of GHGs are typically expressed in a normalized (common) metric so that their impacts can be directly compared (company-to-company, industry-to-industry, or stationary-to-mobile sources), as some gases are more potent (have a higher global warming potential (GWP)) than others.
According to the EPA, the international standard practice is to express GHGs in CO2 equivalents. Emissions of gases other than CO2 are translated into CO2 equivalents using GWPs.
Following are the GWPs developed by the Intergovernmental Panel on Climate Change for several industrial gases:

Type of Gas	GWP (2001)
CO2	1
Methane (CH4)	23
Nitrous oxide (N2O)	296
Hydrofluorocarbon (HFC) 23	12,000
HFC 134a (common refrigerant)	1,300

Emissions reductions from voluntary programs are generally expressed in million metric tons of CO2 equivalent.
Many large companies have published reports that describe trends in their CO2 emissions as a percentage increase or decrease from a baseline year or show a bar or line graph with an increase or decrease of emissions over several years.