Product Sector Guidance: Windows, Doors, and Skylights

Facade of modern building with energy efficient cladding and windows

Windows, Doors, and Skylights

Chemicals used in windows, doors and skylights include many chemicals including formaldehyde, isocyanates, heavy metals, and solvents. This is because the materials used to manufacture doors and windows encompass many found in other sectors. For example, wood doors can have potential formaldehyde and flame retardant issues because of an insulated core or a surface veneer treatment, and vinyl or painted windows, doors, and skylights can contain the same chemicals mentioned in previous sections.

Overall, health complaints from the products are not as prevalent given the smaller amount of materials compared, for example, to the square footage of painted walls or installed insulation.

Installation brings its own concerns, as one-component spray foam is often used to seal the area around a window or door opening. This spray foam is not as toxic as the 2-component used for insulation, but still releases isocyanates. Additionally, VOCs can offgas from adhesives used to construct windows, doors, or skylights.

With windows and doors typically being made locally, products could be delivered shortly after application of these various chemicals, potentially increasing the amount of exposure.

This section is based on the work of Healthy Building Network. Visit Building Products | HomeFree from HBN ( for more product guidance and information.

The chart below lists some of the more frequently used chemicals in this sector’s products.

Product Type

Chemicals of Concern

Health Concerns


Doors, Windows, and Skylights


Adhesives (silicone, polyurethane)


Solvents (toluene, xylene)

PBT, reproductive toxicity, endocrine disruptor, infertility


Cancer and liver toxicity, confusion, death, respiratory irritation, gene mutation

Choose products with third-party certifications 

Composite wood windows and doors


Cancer, gene damage, asthma trigger, birth defects, eye and skin irritant

Choose NAF (No Added Formaldehyde) products or CARB phase 2 compliant products with Ultra Low Added Formaldehyde 

Insulated doors, windows, and skylights

Isocyanates (MDI, PDI)


Halogenated flame retardants

Cancer, asthma trigger, birth defects, eye and skin irritant


Endocrine disruption, reproductive toxicity, cancer, and birth defects

Choose products with third party certifications

Painted Doors, Windows, and Skylights

Alkylphenol ethoxylates (APEs)

Endocrine disruptor, persistent bioaccumulative toxicant

Choose products with third party certifications

Vinyl windows, doors, and skylights


Reproductive,  developmental effects, respiratory problems

Choose Energy Star fiberglass products instead

Composite Wood Products

Formaldehyde is used as a binder in the production of composite wood products including  hardwood plywood, medium-density fiberboard, and particleboard. Emissions from resins in composite wood products is one of the main sources of formaldehyde exposures. Although wood naturally emits trace amounts of formaldehyde, added formaldehyde in composite wood products should be avoided.

Instead, look for products that have been tested and approved as No Added Formaldehyde (NAF) through (California Air Resources Board) CARB or Toxic Substances Control Act (TSCA). At the very least, ensure that all composite wood products are low-emissions certified as compliant with CARB Phase 2 or TSCA Title VI. 

Emissions Standards for No Added Formaldehyde-Based Resins

  • No higher than 0.04 parts per million of formaldehyde for 90 percent of the 3 months of routine quality control testing data.

  • No test result higher than 0.05 parts per million of formaldehyde for hardwood plywood and 0.06 parts per million for particleboard, medium-density fiberboard, and thin medium-density fiberboard.

Healthier Windows, Doors, and Skylights

Look for these labels:






Vinyl products

CARB phase 2 compliant indoor doors with low-formaldehyde emissions

CARB phase 2 / TSCA Title VI with Ultra Low Emitting Formaldehyde Label

ENERGY STAR fiberglass or wood windows and doors


Pre-finished solid wood doors


Composite wood products tested and approved as NAF (No added formaldehyde)


Use low-VOC certified adhesives