Rules
US formaldehyde rules for interior finishes: CARB Phase 2 and TSCA Title VI compared
Formaldehyde rules for interior finishes: how CARB Phase 2 and TSCA Title VI limits, labels and paperwork differ for plywood, MDF and panels.
What to take away
- Formaldehyde rules for interior finishes in the United States now run on two tracks: California's CARB Phase 2 and the federal TSCA Title VI, and a compliant panel has to satisfy both.
- The emission limits are the same numbers, but the panel scopes, testing regimes and paperwork differ, so buyers should compare the two regimes rather than assume one covers everything.
- Labels matter: a TSCA Title VI compliance statement, a CARB Phase 2 stamp or a NAF or ULEF designation each means something different on plywood, MDF and finished goods.
- Documentation travels with the panel, not the showroom sample. Specifiers need mill certificates, certifier names and invoice records that survive an audit.
- OSHA's formaldehyde exposure limits protect installers on site and are separate from the product emission limits that protect building occupants.
Why two formaldehyde regimes exist: CARB Phase 2 and TSCA Title VI on the same panel
California moved first. The California Air Resources Board adopted an airborne toxic control measure for composite wood in 2007, and the Phase 2 limits took effect in 2009 for hardwood plywood, particleboard and medium-density fiberboard. The rule applies to panels sold, supplied, used or manufactured for sale in California, which in practice means most North American mills comply.
Congress then federalized the approach. TSCA Title VI, signed in 2016, directed the U.S. Environmental Protection Agency to set national emission standards for the same three panel types.
The EPA's formaldehyde emission standards for composite wood products page sets out what the rule covers and who must comply. Formaldehyde Emission Standards for Composite Wood Products | US EPA
Because the federal rule was modeled on California's, the two regimes look alike from a distance. Both cap formaldehyde emissions from the same panel families. Both rely on third-party certification and mill records. Both require downstream fabricators and importers to keep the chain intact.
The differences sit in scope and enforcement. TSCA Title VI applies nationwide, including states with no rule of their own. CARB Phase 2 continues to apply in California and, through mill practice, sets the de facto floor across the continent.
A panel sold in Texas or Florida still has to meet the federal rule. If it was made for the California market, it likely carries CARB paperwork too.
For a specifier, the practical question is not which regime wins. It is whether the specific panel in the submittal has documentation for the regime that governs the project, plus any state or local overlay.
California, New York, Washington and Massachusetts have all taken an interest in interior material disclosure, and local code officials can ask for proof. That is where permits, codes and disclosure duties enter the conversation.
Where the limits actually differ: panel types, emission values and testing methods
The headline limits are identical in the two regimes for the three core panel types. Hardwood plywood, particleboard and MDF each have a ceiling measured in parts per million of formaldehyde, and thin MDF has its own value because its surface-to-volume ratio is higher.
The California Air Resources Board's composite wood program page describes the Phase 2 standards and the panel categories they cover. Composite Wood Products Airborne Toxic Control Measure | California Air Resources Board
A direct side-by-side from CARB shows where the two rules line up and where they part. CARB/U.S. EPA Comparisons | California Air Resources Board
The table below summarizes the practical comparison. Values are the regulatory ceilings, not typical mill performance.
| Item | CARB Phase 2 | TSCA Title VI |
|---|---|---|
| Panels covered | Hardwood plywood, particleboard, MDF, thin MDF | Same three families, with thin MDF treated separately |
| Emission limits | Phase 2 ceilings by panel type | Federal ceilings matching Phase 2 values |
| Testing method | ASTM E1333 large chamber; ASTM D6007 small chamber as an alternative | Same ASTM methods, with the same small-chamber allowance |
| Certification | CARB-approved third-party certifiers | EPA-recognized third-party certifiers |
| Label | CARB Phase 2 statement | TSCA Title VI compliance statement |
| Exemptions | NAF and ULEF panels under defined conditions | NAF and ULEF panels under defined conditions |
| Enforcement | CARB and local air districts | EPA, with import holds and penalties |
The testing methods are the same family. ASTM E1333 is the large-chamber reference method, and ASTM D6007 is the smaller chamber method allowed as a correlate.
A mill's quality control program runs periodic tests, and a third-party certifier audits the results. That is why two panels with the same limit can have very different real-world emissions: the limit is a ceiling, and the certification system is what keeps the ceiling honest.
Panel type matters as much as the number. Particleboard used in cabinet boxes, MDF used in door skins and drawer fronts, and hardwood plywood used in shelving all fall under the rule, but the resin systems differ.
Phenol-formaldehyde resins in exterior-grade plywood emit far less than urea-formaldehyde resins in some interior MDF. A specifier comparing wheatboard vs plywood for cabinets is really comparing resin chemistry and moisture performance, not just a label.
Labels, stamps and mill certificates buyers must check on plywood, MDF and finishes
A compliant panel usually carries a stamp or label on the edge or back. The stamp should name the panel type, the emission standard, the certifier and the mill or fabricator. If it only says "low formaldehyde" or "eco-friendly," it is marketing, not compliance.
A CARB Phase 2 label typically states that the panel meets the Phase 2 emission standard for its category. A TSCA Title VI label says the panel complies with the federal rule. Some mills print both because they ship into California and the rest of the country.
NAF and ULEF panels carry different language. NAF means no added formaldehyde resins were used in the panel. ULEF means ultra-low-emitting formaldehyde, a resin system that meets a stricter certification path. Both can be exempt from routine emission testing under conditions set in the rules, but the exemption is not automatic and it does not cover the finished good.
Finishes complicate the picture. A laminate, veneer, paint or UV coating applied over a compliant panel can add formaldehyde or other volatile organic compounds. The panel rule covers the panel, not the assembled cabinet door.
That is why a specifier should ask for documentation on the substrate and the finish, and why the interior material choices checklist starts with substrate before surface.
- Panel stamp names the standard: CARB Phase 2, TSCA Title VI, or both
- Certifier name and mill identification are legible
- Panel type matches the specified product: plywood, particleboard or MDF
- NAF or ULEF claim is backed by a certificate, not a logo
- Finish or coating has its own low-emitting documentation
- Invoice and mill certificate are filed for the project record
- Fabricated components carry traceability back to the panel lot
Documentation chain: third-party certifiers, executive orders and the certified mills list
TSCA Title VI and CARB Phase 2 both depend on a chain of documents. The mill tests and certifies its product. A third-party certifier audits the mill and issues certificates.
The mill then issues executive orders or mill certificates that downstream fabricators and importers pass along. The regulatory text of the federal rule, including the definitions and recordkeeping duties, sits in 40 CFR Part 770. eCFR :: 40 CFR Part 770 -- Formaldehyde Standards for Composite Wood Products
CARB maintains a list of certified mills and approved third-party certifiers. A buyer can check whether a mill on a submittal actually appears on that list, and whether the certifier is approved for the panel type in question. This is the fastest way to catch a forged or expired certificate.
The EPA recognizes third-party certifiers for the federal rule as well. The two lists overlap heavily but not perfectly, so a mill certified under CARB is not automatically on the EPA list unless it has done the federal paperwork. Importers should verify both when goods cross the border.
Executive orders are the mill-level documents that state which panel types and which emission standards a facility is certified to produce. They have expiration dates. A certificate that was valid when the project was specified may be expired at delivery, and an inspector can ask for the current version.
Recordkeeping is not optional. Mills, fabricators, importers and retailers all have retention duties under the federal rule. For a specifier, the practical move is to require the full chain in the submittal: mill certificate, certifier name, executive order number and invoice.
The twenty things to verify first approach applies here as much as it does to any material brand claim.
NAF and ULEF exemptions and what they do not cover
NAF stands for no added formaldehyde. A NAF panel is made with a resin system that does not add formaldehyde during manufacture, such as a soy-based or MDI binder. ULEF stands for ultra-low-emitting formaldehyde, a resin system that consistently tests far below the Phase 2 ceilings.
Both designations can qualify a panel for reduced testing under CARB Phase 2 and TSCA Title VI. The mill still has to certify, and the certifier still has to audit. The exemption is from routine quarterly testing, not from the standard itself.
The exemption does not travel to the finished product. A NAF particleboard core under a decorative laminate is still a NAF panel, but the laminate, adhesive and edge banding are separate materials with their own emissions. A cabinet shop that switches to a NAF core but keeps a high-emitting adhesive has not solved the problem.
The exemption also does not cover installation adhesives, sealants or site-applied finishes. Those fall under volatile organic compound rules, which vary by state and by air district. California's South Coast and Bay Area districts have some of the strictest limits in the country, and New York and Washington have their own requirements.
Finally, NAF and ULEF do not mean zero emissions. They mean the panel's formaldehyde contribution is very low or absent from the resin. Other aldehydes and volatile organic compounds can still be present, which is why a full material review still matters when comparing walls, cabinetry and trim.
OSHA exposure limits for installers versus product emission limits for occupants
Product emission limits protect the people who live and work in a building over years. OSHA limits protect the workers who handle panels and finishes during construction. The two are measured differently and enforced by different agencies. The Occupational Safety and Health Administration's formaldehyde overview explains the workplace limits. Formaldehyde - Overview | Occupational Safety and Health Administration
OSHA sets a permissible exposure limit for formaldehyde in workplace air, plus a short-term exposure limit for brief peaks. The agency also has an action level that triggers monitoring and medical surveillance when exposures reach a defined fraction of the limit. These apply to cabinet shops, millwork facilities and installation crews.
A panel that meets CARB Phase 2 or TSCA Title VI can still produce workplace exposures above OSHA limits in a poorly ventilated shop, especially when cutting or sanding. The product rule and the workplace rule are separate obligations, and a compliant panel does not excuse an employer from monitoring.
For installers, the practical controls are ventilation, dust collection and, where exposures are high, respiratory protection. For occupants, the practical controls are panel selection, finish selection and a flush-out period before occupancy. LEED and other green building programs reward low-emitting materials, but the certification is not a substitute for the regulatory floor.
A verification checklist for specifiers, fabricators and importers
Use this sequence when a submittal arrives. It follows the document chain from the panel to the installed assembly.
- Identify the panel type and the regime that governs the project. Confirm whether the project is in California, another state with an overlay, or a state relying on the federal rule alone.
- Check the panel stamp against the specification. The stamp should name the standard, the panel type and the certifier.
- Verify the mill on the CARB certified mills list and, for federal work, on the EPA-recognized certifier list.
- Pull the executive order or mill certificate and confirm it is current for the delivery date.
- Review the finish and adhesive documentation separately from the panel documentation.
- File the invoice, certificate and executive order together so the chain is auditable after installation.
- Panel type and emission standard match the specification
- Mill and certifier appear on the current approved lists
- Executive order or mill certificate is valid at delivery
- NAF or ULEF claim has a certificate behind it
- Adhesives, laminates and site finishes have their own documentation
- Records are retained for the period the rule requires
- Installation crew has a workplace exposure plan where dust or vapors are significant
Common questions
Do I need CARB Phase 2 if my project is not in California? No, but the panel you buy probably complies anyway. Most North American mills build to CARB Phase 2 because California is a large market, and TSCA Title VI sets the same limits nationwide.
Are CARB Phase 2 and TSCA Title VI limits different numbers? For the three core panel types, the ceilings match. The differences are in scope, certifier lists and paperwork rather than the emission values themselves.
What does a NAF panel actually guarantee? It guarantees the resin system adds no formaldehyde. It does not guarantee zero emissions from the finished assembly, because adhesives, laminates and coatings are separate materials.
Who enforces the federal rule? The EPA enforces TSCA Title VI, including import holds and penalties. CARB enforces Phase 2 in California, and local air districts can add their own requirements.
Do OSHA limits apply to my cabinet shop? Yes. If your shop cuts or sands composite wood, you need to assess workplace formaldehyde exposure against OSHA's permissible exposure limit and action level.
How long should I keep mill certificates? The federal rule sets retention duties for mills, fabricators, importers and retailers. Keep the full chain for at least the period the rule requires, and longer if a project contract demands it.
