Plywood Formaldehyde Emission Standards: E0, E1, and E2 Classification Explained

Plywood contains formaldehyde because resin glues bond the wood layers, and these glues can give off gas as time passes.

This matters for indoor air since higher emissions are linked to irritation and health risks when exposure lasts a long time.

Emission standards set clear limits and help guide safer choices.

E0, E1, and E2 classify plywood by how much formaldehyde it releases: E0 allows up to 0.5 mg/L, E1 up to 1.5 mg/L, and E2 up to 5.0 mg/L.

Lower numbers mean less gas escaping, which helps protect indoor air in homes, schools, and offices.

Let’s look at where emissions come from, how labs measure them, and why the limits vary. There’s also a quick comparison with other rules, a peek at “zero emission” claims, and a guide to spotting these ratings on products.

Does Plywood Contain Formaldehyde? Is It Toxic?

Most plywood uses formaldehyde-based resins to bind wood layers together. Makers typically choose urea-formaldehyde (UF) or phenol-formaldehyde (PF) adhesives.

These resins release gas over time, so plywood can affect indoor air quality, especially in closed-up rooms.

Formaldehyde is a concern because it off-gasses from panels after installation. That can mean eye, nose, or throat irritation if levels climb.

Long-term exposure at higher levels brings real health risks.

Emission class shows risk, not the wood itself.

• E0: ≤ 0.5 mg/L. Very low release. Used where air quality needs strict control.
• E1: ≤ 1.5 mg/L. Low release. Common for homes.
• E2: ≤ 5.0 mg/L. Higher release. Not advised for long-term indoor use.

Some panels use MDI resins that don’t release formaldehyde. That means safer air in bedrooms, schools, and offices when you pick certified low-emission products.

What Is Formaldehyde And Why Is It Used In Plywood?

Formaldehyde is a colorless gas with a sharp, biting smell. Manufacturers use it as a key part of wood resins that act as glue.

In plywood, formaldehyde stays inside cured adhesives at first—it doesn’t just float around as a gas.

Plywood uses these resins because they bond wood layers tightly. The resins harden through a chemical reaction, creating a rigid network.

This glue holds veneers flat and stable under pressure, helping the panel keep its shape in daily use.

Common plywood adhesives include urea-formaldehyde (UF), phenol-formaldehyde (PF), and melamine-formaldehyde (MF). Each one fits a different use.

Small amounts of formaldehyde can release from cured glue over time. This process is called emission. That’s why the E0, E1, and E2 classes exist—to compare plywood products in a way that actually matters for air quality.

Where Do Formaldehyde Emissions In Plywood Come From?

The adhesives used to bond the wood veneers are the main source of formaldehyde emissions in plywood. Manufacturers apply synthetic resins during pressing, and these can give off formaldehyde as the years go by.

The resin type and how it cures both affect emission levels.

Urea-formaldehyde (UF) resin is the most common source. UF cures at low temperatures and bonds well, so it’s used in lots of interior plywood.

But its chemical structure can break down in heat and moisture, which means more formaldehyde gets out. So, in warm or humid rooms, emissions can spike.

Phenol-formaldehyde (PF) resin gives off much less formaldehyde. Its phenolic structure forms stronger, more stable bonds as it cures.

That’s why exterior and structural plywood often uses PF resin—it just holds up better and emits less.

The manufacturing process matters too. Press temperature, press time, and how much resin is used all play a role.

When factories tune these settings, the resin cures more completely, leaving fewer free formaldehyde molecules to escape later.

Natural wood gives off a little formaldehyde, but adhesives are the real source worth worrying about. This explains why E0, E1, and E2 standards focus on tested emission limits, not the wood species.

What Are Formaldehyde Emission Standards For Plywood?

Formaldehyde emission standards set the limits for how much formaldehyde plywood can release into the air. Regulators use milligrams per liter (mg/L) in lab tests to define these limits.

The focus isn’t on whether plywood contains formaldehyde, but how much the standard allows to be released during use.

Manufacturers sort plywood into E0, E1, and E2 classes based on measured emissions. Each class ties a test result to where you can safely use the plywood.

Lower numbers mean lower allowed emissions, which matters most for indoor spaces.

Standard	Emission Limit	Practical Meaning
E0	≤ 0.5 mg/L	Suitable for continuous indoor use, including bedrooms
E1	≤ 1.5 mg/L	Accepted for most homes and offices
E2	≤ 5.0 mg/L	Limited to low-occupancy or non-living spaces

These standards exist because plywood adhesives can release formaldehyde over time. Meeting a lower emission limit means less gas in your indoor air.

Testing agencies measure emissions under controlled conditions before a product earns an E-grade. The grade gives buyers a way to compare plywood options with a clear number, not just vague marketing.

How Formaldehyde Emissions Are Measured And Tested

Testing checks how much formaldehyde plywood releases under specific conditions. Labs control temperature, humidity, and airflow, since those factors change the emission rate.

This control makes results repeatable, which is key for fair comparisons.

Chamber tests are the main reference. ASTM E1333 uses a big environmental chamber to track how much formaldehyde comes off over time.

The chamber controls air exchange and surface area, reporting values in mg/m³. That gives results that match long-term indoor exposure.

EN 717-1 uses a similar chamber setup, just with different loading and airflow rules. The standard ties test conditions to real rooms, so it’s handy for comparing products in Europe.

The desiccator method puts samples in a sealed container with water that soaks up released formaldehyde. Results come out in mg/L.

It’s a closed system, so it works well for quick screening and quality checks at the factory.

Method	Standard	What it Measures	Practical Use
Chamber (large)	ASTM E1333	Emission rate (mg/m³)	Long-term indoor exposure
Chamber (room-scale)	EN 717-1	Emission rate (mg/m³)	Product comparison in EU
Desiccator	JIS / AS methods	Concentration (mg/L)	Quick screening and QC

Labs pick the method based on the standard they need to hit. Matching the test method to the E0, E1, or E2 claim helps avoid confusion.

What Do E0, E1, And E2 Mean In Plywood?

E0, E1, and E2 are formaldehyde emission grades. They show how much formaldehyde plywood gives off into the air.

Formaldehyde mostly comes from the resins used to bond wood layers, so the grade reflects both the adhesive and the testing limits.

E0 grade plywood has the lowest measured emissions. Some regions set E0 at ≤0.050 mg/m³.

Manufacturers use low‑emission or no‑added‑formaldehyde resins for this grade, so it releases less gas. That makes it a better fit for homes, schools, and other closed spaces.

E1 grade plywood allows higher emissions than E0 but still passes indoor use rules in many places. A common limit is ≤0.124 mg/m³.

Builders often go for E1 because it balances emission control with easier sourcing. It’s accepted for interior furniture and paneling when codes allow.

E2 grade plywood has the highest emissions among the three. Its limits exceed E1, and many regions now restrict or phase out E2 for indoor use.

It’s better suited for outdoor or well‑ventilated spots, not living rooms or bedrooms.

E0 Vs E1 Vs E2: Formaldehyde Emission Limits Compared

E0, E1, and E2 tell you how much formaldehyde plywood lets off into the air. Each grade has a specific test limit, measured in milligrams per liter (mg/L), so you can compare them side by side.

E0 plywood sets the bar low at ≤ 0.5 mg/L. Manufacturers hit this mark by using low‑formaldehyde or even non‑formaldehyde adhesives. In real life, these panels barely give off any gas, which is a relief for bedrooms or classrooms.

E1 plywood allows emissions up to ≤ 1.0–1.5 mg/L, depending on where and how it’s tested. Many building codes are fine with this grade because it stays under most indoor safety rules. For most homes and offices, it works just fine without needing special ventilation.

E2 plywood goes higher, up to ≤ 5.0 mg/L. This limit comes from standard urea‑formaldehyde glues that just release more gas over time. If you care about air quality, E2 isn’t for long-term living spaces—it’s better for packaging or temporary uses.

E0 Plywood Explained: What “Zero Emission” Really Means

E0 plywood means the panel releases very little formaldehyde, not literally zero. The E0 tag just means the emission stays under a strict limit during lab testing.

Most E0 plywood clocks in at ≤ 0.5 mg/L in chamber or desiccator tests. Manufacturers tweak adhesive recipes so emissions stay low after pressing and curing. Less chemical odor and lower exposure make daily use more comfortable.

Formaldehyde mainly comes from wood glues like urea-formaldehyde and melamine-formaldehyde. E0 plywood either limits or swaps out these resins for cleaner options. The result? Less off-gassing, since there’s not much free formaldehyde left in the board.

E0 plywood often lines up with strict rules like European E1 and CARB Phase 2. These benchmarks aim to protect indoor air quality. E0 works well for homes, schools, and offices—places where people spend hours inside.

Labels and test reports matter. Always check for third-party certification to make sure you’re getting what’s promised.

E1 Plywood Explained: The Standard For Indoor Use

E1 plywood meets a set formaldehyde emission limit that’s common for indoor wood products. Under desiccator tests, E1 tops out at ≤ 1.5 mg/L. This keeps emissions below most indoor air rules, so it’s fine for use inside homes.

Formaldehyde comes from the resins in plywood glue. Manufacturers control the resin type and curing to keep emissions in check. Over time, the board releases less gas, which helps keep indoor air safer for daily life.

What E1 means for use

• Approved for indoor furniture, cabinets, and wall panels
• Common in bedrooms, living rooms, and offices
• Accepted by many building codes for general residential interiors

With E1, odor issues drop off faster after installation. Move-in times are usually quicker compared to higher-emission boards, since the air clears up sooner.

E1 is the go-to indoor standard. It balances emission control and availability, making it a practical pick when you need indoor approval but don’t want to pay for the strictest grades.

E2 Plywood Explained: Higher Emissions And Usage Limits

E2 plywood allows formaldehyde emissions up to 5.0 mg/L in standard tests. E2 panels usually use urea-formaldehyde resins with less emission control. This keeps costs low but bumps up indoor air risk.

Formaldehyde keeps releasing into the air over time, so higher limits matter. As a VOC, formaldehyde can irritate eyes and lungs with long exposure. E2 plywood needs strict placement limits because of this.

Typical use limits for E2 plywood:

• Packaging and crates
• Temporary structures
• Utility furniture with short service life
• Areas with strong ventilation or outdoor exposure

It’s not recommended for long-term indoor spaces like bedrooms, schools, or hospitals. Closed rooms trap emissions and boost exposure.

E0 shows up in some markets but isn’t recognized everywhere by government standards.

E2 plywood works for jobs where cost outweighs indoor air quality. Clear labeling and careful use help, but safer grades are way better for living spaces.

Is E0 Plywood Really Formaldehyde-Free?

E0 plywood does not mean zero formaldehyde. The E0 grade sets a strict emission cap, usually ≤ 0.5 mg/L, based on lab tests. In reality, the panel still releases tiny amounts, just not much.

Adhesives still bond the wood layers. Most of these resins come from chemical reactions that can leave trace formaldehyde. Completely getting rid of emissions is tough, so E0 just lowers the risk—it doesn’t erase it.

E0 plywood gets its label because tests show emissions stay below the E0 limit. This low number matters for indoor air quality, since long-term exposure is what really counts. In actual homes, lower emissions mean less odor and irritation over time.

Some products say no added formaldehyde. That’s about the adhesive, not the final emissions. Wood itself can let off a little naturally. Labels talk about inputs, while E0 is all about measured output.

E0 plywood signals the lowest widely used emission class. It’s a smart choice for homes, schools, and furniture—anywhere people spend hours every day.

European E Standards Vs CARB Phase 2 Vs EPA TSCA Title VI

European E standards sort plywood by how much formaldehyde it gives off indoors. E1 goes up to 0.124 mg/m³, while E2 allows more. So, E1 panels are good for interiors, but E2 often faces limits in homes and offices.

The E system is about lab test results, not product labels. Since it sets classes instead of legal sale rules, checking test reports is a must. E1 doesn’t always mean legal approval outside Europe.

CARB Phase 2, from the California Air Resources Board (CARB), puts a legal cap on emissions for composite wood. For hardwood plywood, the limit is 0.05 ppm. CARB enforces third‑party testing and labeling, so products need to prove they comply before they hit the shelves.

EPA TSCA Title VI matches CARB Phase 2 for limits and enforcement. Since March 22, 2019, plywood sold or imported in the US must meet TSCA Title VI and carry a compliant label. Any labeled panel meets the same emission cap nationwide.

Standard	Region	Limit Basis	Legal Role
E1 / E2	Europe	mg/m³ air test	Classification
CARB Phase 2	California	ppm chamber test	Mandatory
EPA TSCA Title VI	United States	Same as CARB	Mandatory

How Manufacturers Control And Reduce Formaldehyde Emissions

Manufacturers start by changing the adhesives used to bond wood layers. Many switch from urea-formaldehyde glue to phenol-formaldehyde or no-added-formaldehyde (NAF) resins.

These resins hold onto formaldehyde more tightly, so less escapes into the air. For the user, indoor air stays cleaner after installation.

Some producers use ultra-low-emitting formaldehyde (ULEF) adhesives that meet CARB Phase 2 and EPA TSCA Title VI limits. These rules cap emissions from composite wood panels sold in the U.S.

In practice, this means plywood that’s safe for both homes and businesses. It’s a standard for anyone worried about air quality indoors.

Manufacturers also control emissions through wood selection and drying. They dry veneers to specific moisture levels before pressing.

Too much moisture later breaks down adhesives, which bumps up emissions. Keeping panels stable over time starts with this step.

Pressing methods really matter. Precise press temperature, pressure, and time let the adhesive cure all the way.

Full curing leaves less free formaldehyde in the finished panel. So, when the plywood arrives at the job site, fewer gases escape.

Some factories add post-production treatments that block or absorb emissions. Surface sealers or laminate layers often do the trick.

These layers slow down gas release into the air. That helps panels meet E0 or E1 limits.

• Certified adhesives meeting E0, E1, or CARB-P2 limits
• Process testing using chamber or desiccator methods
• Third-party certification to verify emission results

Low-Formaldehyde And NAF (No-Added-Formaldehyde) Plywood

Low-formaldehyde plywood keeps emissions down by using resins that don’t release much gas. Picking the right adhesive means less off-gassing after installation.

For users, that’s cleaner air in daily life. NAF (No-Added-Formaldehyde) plywood uses resins like soy-based or phenolic systems, which don’t add formaldehyde at all.

Because the core resin skips formaldehyde, emissions usually fall close to what the wood naturally gives off. Fewer odor issues pop up after installation.

“Formaldehyde-free plywood” isn’t always what it sounds like. The label depends on testing, not just the glue recipe.

If any part—like a veneer splice—uses urea-formaldehyde, emissions can still climb, even when the core meets NAF rules. ENF grade sets one of the strictest global limits, capping emissions at ≤ 0.025 mg/m³.

That’s lower than E0. For spaces where people spend hours, this level really matters.

类型	Resin approach	Emission reference
Low-formaldehyde plywood	Reduced-emission resins	Below E1 limits
NAF plywood	No added formaldehyde resin	Meets NAF/ULEF rules
ENF grade panels	Tested to ENF limit	≤ 0.025 mg/m³

Regulations like TSCA Title VI require testing and certification. These rules exist because resin chemistry directly controls how much formaldehyde enters indoor air.

Does Emission Grade Affect Strength Or Durability?

Emission grade doesn’t decide how strong or durable plywood is. E0, E1, and E2 only measure formaldehyde release, not how much weight a panel can handle or how long it’ll last.

Strong plywood is possible at any emission level. Factors like wood species, ply count, veneer thickness, and press pressure matter more.

These details decide how the panel bends, holds screws, and resists cracking. Adhesive choice connects emissions and durability, but it’s not a direct line.

Low‑emission panels often use phenol‑formaldehyde, MDI, or NAF resins. These resins cure fully and resist moisture, so panels stay strong while keeping gas release low.

Some products fail because the process isn’t controlled well—think weak bonding or uneven veneers. That can happen at any emission grade.

Emission grade matters for indoor air. Strength comes from how the panel is built and tested.

Which Emission Grade Is Best For Different Applications?

The right emission grade depends on where the plywood goes and how much time people spend nearby. Fresh air in the space also makes a difference.

E0 grade fits areas with lots of human contact. It keeps formaldehyde emission at ≤ 0.5 mg/L.

This low level works well for furniture plywood in children’s beds, wardrobes, and desks. Lower indoor air buildup matters most in small or closed rooms.

E1 grade suits most homes and businesses. It allows emissions up to ≤ 1.5 mg/L and meets safety rules in many countries.

Furniture plywood, cabinets, wall panels, and flooring often use E1. It’s a balance between cost and emission control.

E2 grade goes to non-living or short-term use areas. It allows emissions up to ≤ 5.0 mg/L.

Manufacturers use it for packaging, temporary fixtures, or utility furniture. Higher emissions make it a poor fit for long-term indoor spaces.

How To Identify Emission Ratings On Plywood Products

Manufacturers usually print emission ratings right on the product label or stamp. You’ll spot marks like E0, E1, or E2 near the brand or panel size.

It’s easy to check the sheet edge or back—no special tools needed. A standards reference often sits next to the rating, like EN standards, CARB P2, or JAS F★★★★.

These standards set the test limits, so their presence shows it’s not just a marketing claim. Certificates or test reports give even stronger proof.

These documents list the test method, measured formaldehyde value, and issuing lab. That way, the rating connects to a real lab result.

• Emission grade (E0, E1, E2)
• Test method (such as chamber or desiccator)
• Measured value (for example, mg/L or mg/m³)
• Lab name and date

Some suppliers include emission data in a product data sheet. If you see a value like ≤ 1.5 mg/L, it shows why the panel qualifies as E1—the measured number matches the standard.

If there’s no label or document, the emission grade is anyone’s guess. For indoor spaces, that’s a risk for air quality compliance.

Pros And Cons Of Low-Emission (E0 / E1) Plywood

Low-emission plywood keeps formaldehyde release in check by using specific resin systems and tighter controls. E1 usually means ≤ 1.5 mg/L, while E0 often aims for ≤ 0.5 mg/L, depending on the test and market.

Pros

• Lower indoor air exposure. Less formaldehyde in the room means fewer odors and less irritation for people living or working nearby.
• Wider acceptance for interior use. E1 meets most interior standards, so it’s common in furniture, cabinets, and flooring.
• Better fit for sensitive spaces. E0 is great for nurseries, schools, and bedrooms where air quality matters most.
• Easier compliance. Builders often pick E1 or E0 to meet air quality rules, which saves time and hassle down the road.

Cons

• Higher material cost. Low-emission resins and testing cost more, so sheets get pricier.
• Limited availability. E0 isn’t always easy to find in every market, which can slow down projects.
• Performance still depends on design. Emission class doesn’t guarantee strength or water resistance—other factors still matter.

Frequently Asked Questions

Is Plywood Toxic To Humans?

Plywood isn’t toxic by itself. The issue comes from certain types that release formaldehyde, thanks to the glue used between layers.

Most panels use urea-formaldehyde resin, which can let off gas into indoor air. Health effects really depend on how much and how long you’re exposed.

Short-term exposure might irritate your eyes or throat. If you’re around it a lot and at higher levels, the risks go up.

Low-emission grades make a big difference for indoor spaces. It’s something worth paying attention to, especially if you care about air quality at home.

Is E1 Plywood Safe For Furniture And Cabinets?

E1 plywood keeps formaldehyde release to 1.5 mg/L or less. This level lines up with common indoor air standards, so you’ll see E1 panels in furniture and cabinets pretty often.

For most homes, E1 plywood works well if the rooms get regular ventilation. Kitchens and closets especially benefit, since doors and finishes help slow down any gas release.

Is E2 Plywood Still Allowed?

E2 plywood has a higher limit, up to 5.0 mg/L for formaldehyde emissions. Some places still allow it in non-living areas, packaging, or for short-term projects.

Many countries now restrict or even discourage E2 panels indoors. Builders should probably steer clear of E2 plywood in bedrooms, offices, and schools—just seems safer that way.

How Can I Seal Plywood To Reduce Formaldehyde?

Sealing blocks gas from escaping the panel and spreading into the air. Water-based polyurethane, acrylic paint, or laminate sheets create a film that slows down emissions.

Edge sealing is just as important as covering the surface. Sealing every cut edge and face cuts indoor exposure way more than just brushing on one side.