Mass timber offers a meaningful opportunity to reduce the embodied carbon of buildings. Compared to conventional structural materials, responsibly sourced wood can lower environmental impacts while supporting regenerative forestry and long-term carbon storage.
To meet North American building codes and standards—such as ANSI/APA PRG 320 for CLT and ANSI A190.1 for glulam—laminated wood products must demonstrate fire resistance under load. In many cases, adhesives that avoid formaldehyde rely on a halogenated flame retardant (HFR) to meet these requirements. As a result, many mass timber products have not been able to achieve Red List Approved status under the Declare label.
This is now changing.
A New Red List Exception
On April 3, 2026, Living Future introduced a new exception within its building and product programs. This update addresses specific cases where a Red List chemical may be required for code compliance and safety, and where safer alternatives are not yet available.
RL-025: Flame Retardants Required for Code in Mass Timber Wood Adhesives establishes a pathway for structural mass timber products—including CLT, glulam, and I-joists—to achieve Red List Approved status when:
- Products must comply with applicable fire and heat resistance standards or building codes
- The flame retardant (CAS 38051-10-4) is used specifically to meet those requirements
- Manufacturers confirm that no alternative adhesive systems can meet the same performance criteria without Red List substances
This approach builds on existing precedents addressing code-driven material requirements within Living Future programs. It was developed in collaboration with industry partners, including Henkel, who provided ingredient transparency, clarified code requirements, and supported engagement with mass timber manufacturers participating in Declare.
Essential Uses: A Red List Reality Check
Living Future remains committed to eliminating the most harmful chemicals from the built environment. This update does not change that goal.
It does, however, acknowledge current constraints. In some applications, certain substances remain necessary to meet safety standards, and viable alternatives have not yet been developed at scale.
This aligns with the concept of essential use—a limited, temporary allowance where a substance is required for health, safety, or critical function, and no safer option exists.
To maintain rigor and accountability, manufacturers must:
- Cite the relevant code or standard driving the requirement
- Provide written confirmation that no safer alternatives are currently viable
The expectation remains clear: continued progress toward Red List Free solutions.
Implications for Project Teams
- Mass timber products with Red List Approved Declare labels can be specified without additional exceptions
- Teams are encouraged to advocate for full ingredient disclosure to 100 ppm
- Ongoing engagement with manufacturers and suppliers will help advance safer chemistry
This update does not apply in Oceania or the European Union, where flame retardants are not required to meet fire code requirements.
Supporting Market Transformation
This update removes a key barrier while maintaining the integrity of Living Future’s materials program.
By enabling broader use of mass timber, it supports:
- The transition to lower-carbon structural systems
- Greater participation in transparency platforms like Declare
- Continued innovation toward healthier material solutions
Mass timber has an important role to play in a regenerative built environment. This update helps align performance, policy, and practice to support that transition.
We look forward to continued collaboration with manufacturers, project teams, and the broader community as this work evolves.Please contact [email protected] with any questions!
