Is pressure treated wood safe for a swing set or playset?

The short answer

Yes. Pressure treated lumber sold for residential use in the US since the end of 2003 contains no arsenic, and CPSC's home playground handbook names it as a material for "playground/residential use"¹. The things that actually go wrong with a treated playset are practical: lumber rated only for above ground use set in the soil, fasteners that corrode, and offcuts burned in the fire pit.

The confusion persists for two reasons. Sets built before 2004 were very likely treated with CCA, which does contain arsenic, and today's copper based lumber is often the same green color. If you have an older set, CCA treated playsets covers how to date it and what to do. Everything below is about lumber you buy now.

What changed in 2003, and what is in the wood now

EPA says CCA makers "voluntarily canceled virtually all residential uses of CCA" effective December 31, 2003, and that before 2004 it went into "decks and playsets"³². CPSC's handbook says the same and adds that the replacements "do not contain arsenic"¹.

EPA lists six preservatives approved for residential lumber: ACQ, borates, copper azole, copper naphthenate, copper-HDO and polymeric betaine³. At the lumber yard you will mostly meet three:

• ACQ (alkaline copper quaternary): copper plus a quaternary compound.
• CA-B and CA-C (copper azole): copper plus one or two azole fungicides.
• MCA (micronized copper azole): copper ground into fine particles that lodge in the wood. The National Pesticide Information Center says micronized copper uses less copper than similar preservatives and tends to leach less⁹.

Is the copper a problem for children?

Some of it reaches hands. NPIC says small amounts of treated wood ingredients in play structures "may transfer to skin or clothing from contact", and that less copper came off on wipes once copper azole and MCA boards had weathered for about a year⁹. A treater's consumer sheet for copper azole says the preservative stays in the wood for a long time but some may dislodge on contact with skin¹¹.

None of the sources here puts a health risk figure on that copper, and none treats it as a reason to avoid treated wood for play. Their advice is hand washing: NPIC tells adults and children to wash after touching treated wood and before eating⁹. Keep snacks off the deck and wash hands after play, a habit cleaning and sanitizing already builds in. Leaching into soil is front loaded too: NPIC says most of it happens in the first few months of use, and metals mostly bind to the soil instead of moving down⁹.

The end tag: ground contact or above ground

This is the decision that decides whether a treated set lasts. Every treated board carries a retention, in pounds of preservative per cubic foot (pcf), and an end tag saying what exposure it is rated for.

The trap is that the same green 4x4 can be either. An above ground board looks identical to a ground contact board, costs a little less, and fails early at the soil line. Timber rot and repair shows where that failure starts.

Which playset parts need ground contact

More than the posts. A February 2016 revision to the AWPA standard moved several physically above ground uses into ground contact¹², and the treaters' evaluation reports now spell them out. ESR-1721 requires ground contact treatment for above ground parts⁴:

1. Critical and hard to replace. Components "difficult to maintain, repair or replace" and "critical to the performance and safety of the entire system". The report's examples are deck joists and beams. A swing beam is the playset member that fits that wording most closely.
2. Close to the ground. Wood less than six inches above final grade, after landscaping, resting on treated wood or concrete. That covers bottom rails, sandbox frames and surfacing border timbers.
3. Debris that stays put. Where soil, vegetation, leaf litter or other debris can build up against the wood. Loose fill surfacing banked against a post does the same thing, and is common on a playset.
4. Frequent wetting, such as a lawn watering system.
5. No airflow underneath, or contact with untreated or decaying wood.

If you set posts in concrete or soil, anchoring covers footing depth, and site prep and leveling covers keeping the finished grade below the wood.

The same rule applies to repairs. A replacement post or beam bought off the shelf for an existing set can just as easily be above ground stock, and nothing on its face tells you which. Check the tag before you pay, and see repairs and replacement parts for sistering a rotten leg with ground contact timber.

Fasteners and brackets: what the code requires

CPSC warns that the copper based preservatives "are known to corrode certain materials faster than others", and tells home builders to check that "nails, screws, bolts, hangers" are compatible with ACQ, CBA and CA-B¹. The residential building code's fastener rule is written for houses and decks, but it is the closest written standard for a timber playset and a sensible floor.

Two details the summaries miss. The code exempts steel bolts 1/2 inch or larger from the coating requirement⁷, but CPSC still wants playset bolts corrosion resistant¹, so buy galvanized. And Simpson Strong-Tie says hot-dip galvanized and stainless parts should not touch each other⁶: pick one metal per connection. The copper azole sheet names ASTM A153 or A653 hot-dip galvanized, or 304 or 316 stainless¹¹.

Bolt ends still have to finish flush or be capped. Hardware and fasteners covers locking nuts and projection limits, and corrosion and rust shows what failing hardware looks like.

Cutting, offcuts and disposal

Handling advice is consistent across EPA, Health Canada and the treater:

• Cutting: wear a dust mask; Health Canada adds eye protection, gloves and long sleeves¹⁰. Clean up all sawdust and debris afterwards¹¹.
• Washing: wash hands before eating, drinking or using the bathroom, and wash work clothes separately¹¹.
• Burning: never. AWPA's standard says treated wood shall not be burned in open fires, stoves, fireplaces or residential boilers⁸.
• Mulch: the copper azole sheet says do not use preserved wood for mulch¹¹.
• Disposal: AWPA cites EPA that homeowners may put treated wood out with ordinary trash⁸. Check local rules.

Dismantling an old set later raises the same questions; moving or removing a playset covers that job.

Dry lumber, sealing and splinters

Treated lumber often arrives wet and moves as it dries, which is where checks and splinters come from, as wood vs metal vs vinyl explains. For handrails, deck boards and anything children grip, ask for lumber kiln dried after treatment. When that drying is specified, AWPA caps each piece of lumber at 19 percent moisture⁸.

Sealing a new treated set is maintenance, not safety. NPIC notes coatings can limit leaching but may take several coats⁹. CPSC adds a constraint: on play equipment, "coatings that contain pesticides should not be used"¹, so read the label before you pick a stain. Painting and refinishing covers preparation and recoat intervals.

What never belongs on a playset

Railroad ties and other creosote treated timber. CPSC says creosote treated wood should not be used¹, and Wisconsin's child care rules bar creosote or pentachlorophenol treated wood, "including railroad ties", from any area children can reach¹³. The same goes for lumber salvaged from a pre-2004 deck: assume it is CCA. What not to use covers the surfacing side of the same list.

Where this stops applying

The retentions above are for US products under ICC-ES reports and differ by brand and species; the end tag on your lumber overrides any table. The building code rules are written for houses and decks, not playsets. Public playgrounds follow ASTM F1487 and their manufacturer's specification, not lumber yard choices. Outside the US, preservative names, retentions and handling rules differ. And no source here quantifies a health risk from copper residue on play equipment; the advice is hand washing, not a dose.

What to do next

If you are building, write "ground contact" next to the posts and the beam on your cut list before you go to the yard, and buy the hardware at the same time. Building a playset yourself covers plans, member sizes and cost. If you would rather not maintain wood at all, choosing a playset and steel, wood and plastic compared weigh the alternatives.