Industry Insights
EPA Subpart C and Section 608, explained for working contractors — organized by the question you're actually asking.
Every leak rate you calculate gets judged against 10%, 20%, or 30% — and which one depends entirely on which appliance category the unit lands in. Here are the three § 84.102 definitions verbatim, where the common equipment actually falls, and what a misfiled category quietly does to your compliance record.
Start here — the site-wide reference
Nine weeks of Subpart C coverage, distilled into one reference guide. Print it. Laminate it. Put it in every truck. This is everything your techs need to know — on every service call, for every covered system.
How the leak-rate math actually works — methods, exemptions, and the edge cases that trip people up.
Since January 1, 2026, every time your tech adds refrigerant to a 15-lb+ system, a leak rate calculation has been required by law. Here's exactly how to do it — with real numbers from real equipment.
Wait — Is That System Even Covered? The Residential Exemption That's Confusing Everyone
Spring Startup Season Is Coming. Do You Know What 'Seasonal Variance' Actually Means?
5 Spring Startup Scenarios That Are Tripping Up Contractors Right Now (And How to Handle Each One)
What "Full Charge" Actually Means — the Number Every Leak Rate Divides By
Comfort Cooling, Commercial Refrigeration, or Industrial Process? The § 84.102 Category That Sets Your Leak-Rate Threshold
What happens after a threshold trips: the federal deadline, its extensions, and the escape hatches.
Your tech calculated a leak rate above the threshold. The 30-day clock is running. Here's the step-by-step workflow — from detection through repair, verification testing, and what happens if the fix doesn't hold.
The Verification Test Is the Only Thing That Closes a Repair (§ 84.106(e))
Can't Repair in 30 Days? The Extension You File With the EPA — Before the Clock Runs Out
Repairs Won't Fix It? The Retrofit-or-Retirement Plan You File With the EPA — 30 Days to Write, One Year to Finish
Automatic Leak Detection Is Now Mandatory on Big Systems — Is Your Customer's Covered? (§ 84.108)
The Repair Passed. You're Not Done — the Leak-Inspection Schedule Just Started
The 125% rule, the March 1 EPA report, and the decisions a chronic leaker forces.
There's a second threshold most contractors aren't tracking. If total refrigerant added to a system exceeds 125% of its full charge in a calendar year, you must file a report directly with the EPA by March 1st. Here's how that math works — and how fast it adds up.
Month Five and Counting: How to Watch Your Chronic-Leaker Totals Before Summer Service Calls Push Them Over the Edge
Repair, Retrofit, or Retire? The Three-Door Decision When a Chronic Leaker Stops Being Worth Fixing
How to Actually File the Chronic-Leaker Report With the EPA — CDX, HAWK, Form 3520-36, and the 12 Fields Due March 1
Recovery, Evacuation, and the Disposal Record: How to Retire a System Without Leaving a Compliance Hole
Paperwork that survives an inspection — checklists, teardowns, and the mistakes to stop making.
Eighteen weeks of records. The day someone with a credential asks to see them, you'll know whether you built a defense — or a stack of paper. Here's what an EPA inspection actually involves, the ten records you'll be asked for, and the three mistakes that turn a routine inspection into a citation.
Your First Subpart C Quarter Is Almost Over. Here's the Compliance Audit You Should Run This Week.
The Mid-Year Subpart C Audit: Six Checks to Run on Your File Cabinet Before July 1
The Service Ticket That Survives an Inspection (and the One That Doesn't): A Field-by-Field Teardown
5 Refrigerant Documentation Mistakes Your Techs Are Making Right Now (And How to Fix Them This Week)
Busy Season Is Here. Here's How to Keep Your Leak Documentation From Falling Apart When Service Calls Triple.
The Records That Have to Survive Three Years (and What "Electronic Is Fine" Really Means)
Type I, II, III, or Universal: Which 608 Card Lets Your Tech Legally Touch Which System
The phasedown in practice: new rules, new refrigerants, new truck-stock habits.
The EPA dropped the refrigerant reporting threshold from 50 to 15 pounds on January 1, 2026. Your customer's 5-ton rooftop unit is now federally regulated — here's what that means for your shop today.
The EPA Just Changed the Refrigerant Rules. Here's What It Means for Your Leak Logs: Nothing.
The TT Rule Just Hit the Federal Register. Your Subpart C Compliance Didn't Move an Inch.
First A2L Service Summer: Six Truck-Stock and Habit Changes Before the 90° Weekend Hits
You're Buying Reclaimed Refrigerant. But Is It Actually Reclaimed? The 15% Virgin Content Rule, Explained.
The Disposable Cylinder Ban Everyone's Planning Around Doesn't Exist. Here's the 2028 Rule That Does.
Refrigerant Costs Are Climbing. Are You Tracking What Every Leak Actually Costs Your Customers?
The Subpart C Rule That Has Nothing to Do With Refrigerant: §84.110 and the Clean-Agent Systems in Your Customers' Buildings
Who's covered, who's liable, and what enforcement actually looks like — the field reference above is the map.
Owner or Contractor — Who Does the EPA Actually Fine Under Subpart C?
Your Contractor's Records Are Not Your Records: the § 84.106(l)(4) Handoff Every Building Owner Is Missing
Your Walk-In Is Probably Federal: the 15-Pound Line for Grocers, Restaurants, and Property Managers
Two Rules, One Deadline: Why 'The EPA Relaxed the Rules' Could Cost You $59K a Day
EPA 609 Isn't 608: The Certification Boundary That Runs Down the Middle of Your Truck
A $2.5 Million Refrigerant Settlement Just Landed. Here's What It Teaches a Five-Truck Shop.
Subpart C Is the Floor, Not the Ceiling: State Refrigerant Rules That Could Catch You Off Guard
How to Talk to Building Owners About Subpart C (And Turn Compliance Into Your Best Sales Tool)
Section 608, the AIM Act leak-repair program, penalty and deadline changes — one alert naming the change and citing the regulation, checked against the Federal Register and eCFR before it goes out.
Every post above cites the regulation it explains — and Ref LeakLog runs the same math on your own fleet: leak rates, deadlines, and audit-ready records, computed automatically.