OPACITY VISIONProvider-specific
The approval applies to the described Opacity Vision system and procedures—not to every VR application or headset-based training product.
EPA-approved alternative ALT-152C
EPA ALT-152C approval for Opacity Vision’s VR Method 9 system.
Read the provider-specific approval and learn what it authorizes for headset-based Method 9 plume demonstrations and observer certification.
What is ALT-152C?
ALT-152 is a broadly applicable alternative to the certification procedures for opacity observers under Section 3.2 of Method 9. Providers do not inherit that authorization automatically: each entity seeking to qualify observers through its VR system must document its system, demonstrate it, and receive the applicable approval.
Evidence-based
The EPA review considered documentation, a demonstration, and performance information submitted for the alternative system.
Method-specific
The authorization concerns the alternative procedure for conducting Method 9 plume demonstrations and certification as described in the approval.
What EPA concluded
In its approval letter, EPA concluded that Opacity Vision’s headset-based alternative method yields observers capable of conducting opacity observations with equivalent or better accuracy than observers certified using the existing Method 9 procedures.
That conclusion is important. So are the boundaries: training and certification must be conducted using the approved system as described, and regulatory acceptance for a particular activity may still depend on the applicable agency, jurisdiction, permit, or employer.
Use the exact approval
Opacity Vision identifies its approval as ALT-152C. When evaluating a VR provider, ask for the provider-specific approval letter and confirm that the actual system, equipment, and process being offered match it.
From approval to a usable company program
Regulatory authorization makes the certification path possible. Operational design makes it practical across a workforce.
Correct equipment
Guide users toward the approved VR workflow and make device requirements visible before an official test begins.
Controlled testing
Preserve official test timing and browser-session controls while supporting appropriate recovery when a technical interruption occurs.
Accountable records
Connect certification results to the right student, facility, company, and primary contact for practical follow-through.
ALT-152C questions
Is ALT-152C the same as EPA Method 9?
Method 9 is the underlying federal method. ALT-152C is the approval applicable to Opacity Vision’s alternative VR-based approach to specified observer certification procedures.
Does ALT-152C approve all virtual smoke schools?
No. EPA’s framework requires a provider seeking to conduct VR training and certification to satisfy the applicable criteria and obtain approval for its documented system.
Where can I verify Opacity Vision’s approval?
You can read the ALT-152C EPA approval letter hosted on this site and consult EPA’s approved-alternatives materials.
Primary sources: Opacity Vision ALT-152C approval letter and U.S. EPA approved alternative test methods.
Continue learning
Read the Method 9 certification guide, compare VR and in-person smoke school, review supported VR headsets, or explore virtual smoke school.
Reviewed by the Opacity Vision Method 9 training team. Updated August 31, 2026.