Overview
Halogen-free is a voluntary specification for electronics rather than a legal requirement. A product is usually called halogen-free when bromine and chlorine stay below agreed thresholds. The term sets a target for the materials in a board or component, and it ends up written into customer specifications and supplier declarations.
What the thresholds mean
A widely used reference is IEC 61249-2-21. It sets bromine at most 900 ppm, chlorine at most 900 ppm, and total halogens at most 1500 ppm. These numbers come from the standard, not from law, so a buyer is free to set tighter or different limits in a contract. Meeting the thresholds is what lets a supplier label material as halogen-free.
Why it matters
The push comes from concerns about brominated flame retardants, including PBDE, and the brominated dioxins they can form. Customers respond by demanding halogen-free parts, which turns the specification into a declarable item flowing through the supply chain.
Halogen-free is a specification, not a ban. The legal restrictions on specific brominated substances are separate, so a part can be halogen-free yet still need its own compliance checks.
Note: general educational information, not legal advice. Check the official source before relying on it.