EPA METHOD 9 BASICS

EPA Method 9 is a test method to determine the opacity of visible emissions. Let's dissect that to fully understand what it is and why it is so important.

What Are Visible Emissions?

Visible emissions are any air emissions that result from a source or a process. Visible emissions can come from point sources such as smokestacks or fugitive sources such as quarries.

Example of visible emissions from an industrial source
Another example of visible emissions

What is Opacity?

Opacity is the degree to which matter obstructs the transmission of light. Opacity is how visible emissions are measured. 0% opacity means there are no visible emissions. 100% opacity means the visible emissions block all light. Watch this video for a demonstration of opacity.

What is Smoke School?

Most air-emitting sources are subject to opacity limits. To determine whether a facility is in compliance with these limits, individuals are trained and tested through a smoke school. Smoke school is the process of training and certifying individuals to visually evaluate and quantify the opacity of visible emissions using visual memory.

VR Smoke School logo

What Are the Components of Smoke School?

Smoke school consists of a lecture and a visual test. The lecture teaches proper visible emission observation and documentation procedures. The visual test teaches students how to assess opacity and tests them on their assessment accuracy.

The visual test can be completed using a virtual reality headset or by attending an in-person visual test. Students must accurately assess 50 smoke plumes to pass the visual test.

VR Smoke School lecture interface
VR Smoke School headset

What is EPA Method 9?

EPA Method 9 is a test method developed by the U.S. EPA to assess the opacity of visible emissions. To conduct an EPA Method 9 test, an individual must be certified by successfully completing a smoke school. EPA Method 9 certification is valid for six months, and the visual test must be passed every six months to maintain certification.

U.S. EPA logo

Who Uses EPA Method 9?

A wide range of organizations and industries require personnel to have EPA Method 9 certification.

Commercial & Industrial Sources

Tens of thousands of facilities with the potential to emit matter into the air will have personnel who are EPA Method 9 certified to ensure they comply with air regulations.

  • Power generation facilities
  • Mining & quarry operations
  • Manufacturing facilities
  • Data centers
  • Hospitals
  • Waste facilities
  • Incinerators - hospitals, crematoria
  • Shipping (oceanic, rail, air)
Commercial and industrial facilities

Regulatory Agencies

Federal, state and municipal regulatory agencies have inspectors who ensure opacity limitations are not exceeded at commercial facilities. These individuals must have EPA Method 9 certification.

Regulatory agencies personnel

Environmental Consultants & Stack Testers

Commercial sources hire consultants and stack testers to perform compliance testing on their emission sources. These individuals must have EPA Method 9 certification.

Environmental consultants at work

Community & Environmental Groups

Community watch groups often form in areas where repeat opacity violations occur and directly impact the surrounding community. Environmental groups also monitor opacity at facilities with a history of exceeding opacity limits, or in regions where increasing air pollution indicates that action is needed.

Community environmental groups

The Importance of EPA Method 9

EPA Method 9 testing is one of the easiest and most effective ways to monitor and reduce air pollution. No expensive tools are needed and it can be performed instantly, with minimal training.

Industrial site with emissions

Air pollution contributed to about 8.1 million deaths worldwide in 2021, making it the second-leading global risk factor for death after high blood pressure and ahead of tobacco and poor diet.

Crops affected by pollution

Air pollution affects more than human health. It can damage crops, forests, waterways, and buildings, and contributes to reduced visibility in national parks and wilderness areas.

Earth with smoke pollution

At least 92% of the world's population lives in places where air pollution exceeds safe limits.

City skyline with smog

According to the American Lung Association, approximately 156 million Americans live in areas with unhealthy levels of air pollution.

Atmospheric pollution

According to the EPA, about 66 million tons of pollutants were emitted into the atmosphere in the U.S. in 2023.

Ready to Earn Your EPA Method 9 Certification?

Help reduce the deadliest form of pollution in the world. Register now for free, unlimited access to the VR Smoke School Program. Only pay when you pass and choose to unlock your certification.