Sawn-from-the-log hardwood plank — no plywood backer, no urea-formaldehyde, refinishable for generations.

This material screens clear across all seven independent toxicology authorities we use on every project.
Solid wood flooring is exactly what the name says: a single piece of hardwood, sawn from the log, milled with tongue-and-groove edges, kiln-dried, and finished. Unlike engineered wood (which is a thin veneer over a plywood or HDF substrate bonded with adhesive), solid wood has zero added binders. The finish chemistry matters — specify natural oils, hard-wax oils, or water-based polyurethane rather than solvent-based polyurethane. Solid plank can be sanded and refinished 4-6 times over its life, meaning a single floor lasts 100+ years with reasonable care. Refer to FSC Lumber for the certified-sustainable sourcing side.

Severity scored 0–10 against the same 10 hazard endpoints we use for the chemical families on the avoid list. Every score is 1–2 — essentially no signal across every endpoint.
Listed alphabetically. Where in a home this material earns its keep.
We specify Solid Wood Flooring because it survives the screening. Nothing goes into one of our homes until it clears all seven toxicology databases we check — that is what makes a toxin free home different from a home marketed as one.
If you are planning a new house or a deep remodel and you want this level of material control, that is the whole job we do. Earth Bound Homes builds in Menlo Park, Redwood City, San Mateo County and across the San Francisco Bay Area.