Non-Toxic Decking Material Options

Fully updated in August 2025

This is a complete guide to non-toxic decking – types, materials, additives, and brands.

For most people, the main choice is between composite decking and solid wood decking.

For the chemically sensitive, you will have to get samples yourself of the decking materials as well as the stains needed for real wood – as this choice is very individual.

The long-term benefits of not having to do any maintenance on composite decking can outweigh the initial concerns.

There are also some more unusual options to choose from like aluminum decking.

Things to consider:

• There is a potential for contaminants in recycled PVC, depending on the source of the plastic. Decking is rigid and the recycled plastic will be mostly rigid (unplasticized) as well, though one brand confirmed that some plastic with phthalates does find it’s way in.
• Contaminants could be present in recycled plastics of all kinds, the exact contaminant depends on the source of the plastics (most of the composite decking products don’t likely contain major contaminants of concern if they are made of plastic bags and milk jugs).
• PVC has a big environmental impact.
• I don’t have any direct evidence of PFAS used in plastic (or other) decking materials; however, PFAS are frequently used on plastic molds in factories, so there is a chance that PFAS are present even if not directly added as an ingredient in the materials.

Composite Decks

Material Make Up

Composite decking material is generally made from a mix of wood fibers and plastic.

The plastic is polypropylene (PP) or polyethylene (PE), mixed together with wood dust, pigments, UV inhibitors, and usually borate.

This plastic is often recycled (but not in all brands), like from plastic grocery bags. (If you are worried about contaminants there you would need to check the source of the plastic; recycled bags are mostly fine, other sources may not be).

If you do well with polyethylene or polypropylene, that should be OK for you, but ask to see a sample of the ones available near you and see if you can get a sample of one that is as newly manufactured as the one you would buy.

These plastics do have a little bit of odor.

Most of the decking boards are capped in an outer layer of plastic.

The type of plastic is not always specified, but you should ask, especially if you are avoiding PVC vinyl.

Additional Chemicals During Install

Glue is not used to install composite decks, but you are meant to seal the rough edges of some brands with a lumber wax – be sure to test out the product that the company recommends, if you are super sensitive.

Trex does not recommend using a lumber wax, sealant, or any other glue or sealant in the installation.

The only maintenance needed for most brands is soap and water.

Mold Prone?

Many have reported their composite decking becoming prone to growing mold.

Some lines have been discontinued due to issues, including mold.

Some experts have recommended only going with brands that are capped with plastic on all sides to help prevent this issue. Others believe that capping it on only three sides encourages drying better.

Brands

Capped composites like Trex Transcend or TimberTech Earthwood Evolutions use a traditional composite decking core with an added plastic polymer cap.

Trex is the most well-known brand of composite decking made with recycled bags (PE), and it is capped with an unspecified type of plastic, which they said is not PVC (re-confirmed in 2025).

Dura-Life brand is a blend of polypropylene and wood fiber, with a polypropylene cap.

I have heard from really chemically sensitive folks who did well with Dura-Life.

I sampled this one, and I would describe the odor as a fairly mild glue odor when sniffed directly.

A non-wood composite, Lumberock Premium Decking, offers a line of decking materials made from a combination of HDPE plastic and mineral materials instead of wood fibers.

You might want to check that one out if you are sensitive to the natural odorants of wood.

Wood-based composites do still retain some wood odor.

For example, a cedar composite that I tested definitely smelled like cedar.

The ones I tested (Trex, Dura-Life) also have an odor that I would describe as a light glue odor.

Maintenance

Non-toxic cleaning products that won’t damage composite decks are here.

PVC Decking

Material Make Up

When I first wrote this article in 2021, there were a few brands of PVC-wood composite decking (Certainteed EverNew some of the TimberTech lines, Envision), but most have been discontinued.

Current PVC options:

• The only PVC-wood composite I see in 2025 is Eva-Last Apex (PVC-bamboo core with acrylic cap).
• Though one brand below is a composite capped in PVC.
• There are also decking materials that are 100% PVC (then and now).

Many chemically sensitive folks often avoid PVC, but that is mostly due to the problems with more flexible PVC (odors, plasticizers, etc.)

Rigid PVC, while not great for the environment, does work for some chemically sensitive folks.

Additional Chemicals During Install

With solid PVC boards, you would not need to seal the edges.

Mold Prone?

Mold growth would only be superficial on solid PVC boards since it cannot grow in the material.

Brands

TimberTech Advanced is made from a solid PVC (partially recycled), which they claim is highly resistant to stains, scratches, splits, mold, and mildew.

Despite being PVC, I found that the TimberTech solid PVC only had a slight odor when new (when sniffing it up close) – less than the odor of TREX and Dura-LIfe composites, in my opinion.

They use some recycled PVC, most of it is unplastized, but some of it could contain phthalates, the company said in an email in 2025. They do not add additional phthalates to their PVC, since it is rigid.

Eva-Last Apex is cellular PVC reinforced with bamboo. The boards are encapsulated in an acrylic polymer.

Fiberon company makes surface decking, railing components, and fencing products that are made from a PVC called “Permatech” outer cap bonded to a wood composite core (which is wood-polyethylene).

One thing to ask each company about is phthalates.

Maintenance

Non-toxic products that won’t damage vinyl decks are outlined in this post on deck cleaners.

Real Wood Decks

Pressure Treated Decks

Pressure-treated wood for decking is usually pine, treated with copper and quaternary ammonia.

The ammonia will off-gas from the pine, but for those who are extremely sensitive, they can have challenges with this when it is fresh.

I have also seen pressure-treated wood treated with flame retardants, though this is not the norm.

One other challenge with pressure-treated wood is that it can not be sealed or stained for about 6 months when it is new unless it’s already been dried out.

Cedar Decks

Cedar is the most common natural wood option and it’s good for those avoiding toxins since it doesn’t need pressure-treating (with copper-quats) like pine does.

Cedar does have a rather strong natural odor which bothers some people with extreme chemical sensitivity.

My post on the odorants of wood looks more at this issue.

Although it doesn’t require pressure treating you should stain it every few years, so you will have to find a sealer you do well with.

My post on deck sealers goes through the options.

Typically, the base structure of decks is made from pressure-treated wood.

Redwood is another naturally rot-resistant wood used for decking in North America. Like Cedar, it is not pressure-treated and does require a sealant.

Cedar and Redwood are pricier than pressure-treated pine.

Ipe Decks

Ipe is a wood species for decks that could be ideal for those avoiding toxins.

Though it’s quite pricey, pricier than Cedar and Redwood, it does not require sealing (or pressure-treating).

Though adding a sealer can help preserve it.

You can choose between natural oil options and a very low VOC oil/water hybrid detailed here.

Other Rot-Resistant Woods Used in Decking

Massaranduba, Cumaru, Tigerwood, Garapa, Mahogany, and Teak are a few other naturally rot-resistant tropical woods that can hold up as outdoor decking.

Out of the woods used for decking that I tested, Cedar is the highest-odor wood and Garapa is the lowest.

If you find yourself sensitive to the natural odorants of wood, get a few samples of different species and see how you do.

Non-Toxic Modified Woods

Thermally Modified Wood

Thermally modified wood for decking is treated with heat.

This makes it more durable and gives it protection against rot and termites. 

No chemicals are used in the treatment.

It has the smell of smoked wood.  

Thermory is a heat-treated wood brand, they say it lasts as long as a tropical hardwood like Ipe.

There is a wax to seal the edges of Thermory.

Other than those edges, it comes finished and you don’t have to refinish this again if you don’t want to.

Acetylated Wood

Accoya wood is Radiata Pine treated with acetic anhydride.

The treatment leaves the wood harder, more dimensionally stable, and immune to insects.

Some acetic acid is left in the wood and that does leave it smelling a little bit like vinegar.

You can add a finish or leave it unfinished.

Furfurylated Wood

Kebony is another modified wood.

Furfuryl alcohol is impregnated into the wood and is polymerized.

I do not have any data on how chemically sensitive folks do with this product.

Aluminum Decking

Aluminum decking by Nexam is made from powdered coated aluminum.

A chemically inert product and certainly the safest one on this list for the extremely chemically sensitive.

Some types are gapless which can help to provide a usable area under the deck.

Related:

Non-Toxic Deck Stains & Sealers

Non-Toxic Deck Cleaners

Corinne Segura is an InterNACHI-certified Healthy Homes Inspector with certifications in Building Biology, Healthier Materials and Sustainable Buildings, and more. She has 10 years of experience helping others create healthy homes. You can book a consult here.

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