Which grade an export market asks for
US-bound panels and panel products fall under CARB Phase 2 and the federal EPA TSCA Title VI rule, both tested to the ASTM E1333 chamber method: particleboard is capped at 0.09 ppm, MDF at 0.11 ppm and thin MDF at 8 mm and under at 0.13 ppm.
Japan references JIS F★★★★ under JIS A 1460, a desiccator test with a mean limit of 0.3 mg/L. The four-star mark is the grade named on JAS building-material specifications for panels sold into Japan.
The European Union sets E1 as its regulatory floor under EN 13986 and EN 717-1 (chamber test, 0.124 mg/m³ or 0.1 ppm), and many EU buyers specify E0 or ENF on top of that floor for interior and childcare products.
China's domestic market works to GB/T 39600-2021, tested in a 1 m³ climate chamber: E1 at 0.124 mg/m³, E0 at 0.050 mg/m³ and ENF at 0.025 mg/m³, the three grades most often called out on domestic tenders.
Grades by regime, test method and limit
The table lines up every grade against the test that measures it and the market where that grade is the reference. Two rows share the name E1 because China and the EU both use it, tested to different but numerically aligned chamber methods.
| Grade | Regime and test method | Limit | Reference market |
|---|---|---|---|
| E1 | China GB/T 39600-2021, 1 m³ climate chamber | ≤ 0.124 mg/m³ | China (domestic baseline) |
| E1 | EU EN 13986 / EN 717-1, chamber method | ≤ 0.124 mg/m³ (0.1 ppm) | European Union (regulatory floor) |
| E0 | China GB/T 39600-2021, 1 m³ climate chamber | ≤ 0.050 mg/m³ | China (premium domestic grade, also specified voluntarily in the EU) |
| ENF | China GB/T 39600-2021, 1 m³ climate chamber | ≤ 0.025 mg/m³ | China (top domestic grade; no-added-formaldehyde resin systems) |
| CARB Phase 2 / EPA TSCA Title VI | ASTM E1333 chamber method | 0.09 ppm particleboard, 0.11 ppm MDF, 0.13 ppm thin MDF ≤ 8 mm | United States |
| JIS F★★★★ | Japan JIS A 1460, desiccator method | mean ≤ 0.3 mg/L | Japan |
What ENF means
ENF stands for no-added-formaldehyde: the resin system in an ENF panel is formulated without added formaldehyde, which is why China's GB/T 39600-2021 sets its limit at 0.025 mg/m³, half the E0 limit and a fifth of the E1 limit under the same 1 m³ chamber test. The grade order runs E1, then E0, then ENF, each step lowering the emission ceiling under the identical test method.
Because ENF, E0 and E1 all run through the same GB/T 39600-2021 chamber, the three grades are directly comparable within China's domestic system. The comparison does not carry across to CARB Phase 2 or JIS F★★★★ without a fresh test, since those regimes sample air in different chambers and report in different units.
Test methods do not convert one to one
A 1 m³ climate chamber (China, EU), an ASTM E1333 chamber (United States) and a JIS A 1460 desiccator (Japan) measure formaldehyde release under different airflow, loading and sampling conditions, and report the result in different units: mg/m³, ppm or mg/L. No fixed multiplier turns one into another.
The practical rule for a buyer: specify the grade your market regulator names, rather than converting a limit from one country's test into another's. A panel certified E0 under GB/T 39600-2021 and a panel certified to CARB Phase 2 have each cleared their own regulatory bar, and the two certificates serve their own markets side by side.
One panel programme, every grade
Ningfeng manufactures particleboard, MDF, HDF and OSB on ten continuous-press lines and holds all five formaldehyde grades, E1, E0, ENF, CARB P2 and JIS F★★★★, across that range. The panel type is chosen for the component (carcass, front, flooring core, feature surface); the emission grade is set to match wherever the finished product ships.
A single order can specify CARB Phase 2 particleboard for a US-bound cabinet run and ENF MDF for a China domestic tender in the same product family, because grade sits on top of the panel rather than limiting which panel is available.
Questions buyers ask
Which grade do I need for the US market?
CARB Phase 2 and EPA TSCA Title VI, both tested to the ASTM E1333 chamber method: 0.09 ppm for particleboard, 0.11 ppm for MDF and 0.13 ppm for thin MDF at 8 mm and under. Ningfeng holds CARB Phase 2 across its particleboard and MDF range.
Is ENF the same as E0?
No, ENF is one step below E0. Under China's GB/T 39600-2021 chamber test, E0 is capped at 0.050 mg/m³ and ENF at 0.025 mg/m³, half that limit, using a no-added-formaldehyde resin system.
Can the same panel be certified for several markets?
Yes. Ningfeng runs particleboard, MDF, HDF and OSB through all five grades (E1, E0, ENF, CARB P2, JIS F★★★★), so the same panel construction can be specified to the grade each destination market names, without changing which panel type is ordered.
What does F★★★★ mean on a Japanese order?
F★★★★ (four stars) is Japan's JIS reference grade under JIS A 1460, a desiccator test with a mean limit of 0.3 mg/L. It is the grade named on JAS building-material specifications for panels sold into Japan.
Why can a formaldehyde limit in mg/m³ not be compared directly with one in ppm or mg/L?
Because each unit comes from a different test: a 1 m³ climate chamber (mg/m³, used by China and the EU), an ASTM E1333 chamber (ppm, used by CARB Phase 2 and TSCA Title VI) and a JIS A 1460 desiccator (mg/L, used by Japan) sample air under different conditions. Specify the grade your market regulator names rather than converting between them.