Adapting GHS Labelling for Nanomaterial Reagents under the 2026 Regulatory Updates

What are the key changes to GHS in the 2026 revision that impact nanomaterials?

The United Nations Economic Commission for Europe (UNECE) released GHS Rev. 11 in 2025, with the 2026 implementation date covering nanomaterial reagents explicitly. The revision adds a dedicated nanomaterial classification criteria set, mandating that any substance with at least 50 % of particles below 100 nm be evaluated for nano‑specific hazards such as inhalation toxicity, dermal penetration, and environmental persistence. The update also introduces a new hazard class – Nanomaterial‑Specific Physical Hazard – which requires a distinct label element when the material exhibits properties like high surface reactivity or catalytic activity that are not captured by existing classes.

In practice, this means that a bulk chemical previously labelled only with standard GHS symbols may now need an additional nanomaterial pictogram if the same chemical is supplied as a nanoparticle suspension. The 2026 revision also clarifies the use of signal words: "Danger" remains for acute toxicity, while "Warning" is recommended for chronic nano‑hazards such as long‑term pulmonary effects.

For reference, the UNECE documentation outlines the exact particle‑size thresholds and the required wording for nano‑specific labelling [UNECE GHS Rev. 11 – 2025].

How should safety data sheets (SDS) be updated for nanomaterial reagents?

Section 1 (Identification) of the SDS must now include a statement of nanomaterial status, e.g., "Contains engineered nanomaterials (average particle size 30 nm)." Section 2 (Hazards Identification) requires the addition of nano‑specific hazard classifications, with corresponding GHS codes (e.g., H351 for suspected carcinogenicity via inhalation of nanoparticles). Section 3 (Composition/Information on Ingredients) should list the nanomaterial component separately, providing its CAS number, average size distribution, and surface coating if applicable.

Section 11 (Toxicological Information) is expanded to demand data on nano‑specific endpoints: inhalation LC₅₀ values for aerosolised particles, in‑vitro cytotoxicity assays, and any available animal inhalation studies. Where data are lacking, the SDS must note the uncertainty and reference the applicable REACH or TSCA nanomaterial guidance.

The updated SDS format aligns with the PubChem GHS repository, which now hosts nanomaterial hazard classifications and can be used to cross‑check the appropriate GHS codes [PubChem GHS].

Which pictograms and signal words are mandatory for nanomaterial classification?

GHS Rev. 11 retains the nine standard pictograms but adds a supplementary nanomaterial symbol: a stylised particle cluster within a circle, coloured orange, to be placed adjacent to any existing pictogram that applies. The new symbol is mandatory when the nanomaterial exhibits any of the following:

• Enhanced reactivity (e.g., catalytic nanometals)
• Respiratory sensitisation or toxicity at the nano‑scale
• Persistent environmental toxicity specific to nano‑forms

Signal words follow the existing hierarchy: "Danger" for acute nano‑toxicity (e.g., H330 – Fatal if inhaled) and "Warning" for chronic or less severe nano‑hazards (e.g., H317 – May cause an allergic skin reaction). The label must also include the phrase "Nanomaterial – handle with appropriate respiratory protection" when inhalation risk is identified.

What practical steps can laboratories take to implement the new labelling requirements?

1. Inventory audit – Compile a list of all reagents that are supplied or stored as nanomaterials. Verify particle‑size data from certificates of analysis (CoA) or supplier specifications.
2. Gap analysis – Compare existing SDS and labels against the Rev. 11 criteria. Flag any missing nano‑specific hazard statements or pictograms.
3. Supplier liaison – Request updated CoA and SDS from vendors, citing the 2026 GHS requirements. Molekula, for example, provides nanomaterial‑specific documentation on request.
4. Label redesign – Use a label template that accommodates the additional nanomaterial pictogram and the expanded signal‑word field. Ensure the label size complies with OSHA’s HazCom standards for legibility (minimum 6 mm character height) [OSHA HazCom].
5. Training – Conduct a brief refresher for laboratory personnel on nano‑specific PPE (e.g., N95 or P100 respirators, glove materials compatible with nanoparticle penetration) and waste segregation procedures.
6. Documentation – Record the date of label revision, the responsible chemist, and the version of the SDS used. This audit trail is essential for compliance inspections under REACH and TSCA.

By following these steps, laboratories can achieve a seamless transition to the 2026 GHS framework while maintaining safety and regulatory integrity.

Frequently asked questions

Q1: Do the new nanomaterial pictograms replace the existing GHS symbols? A: No. The nanomaterial symbol is supplementary and must be displayed alongside any standard pictograms that apply to the substance.

Q2: Is a separate SDS required for each nanomaterial formulation? A: Yes, each distinct nano‑form (different size distribution, surface coating, or carrier) needs its own SDS reflecting the specific hazards.

Q3: How long will existing labels be valid after the 2026 deadline? A: Labels must be updated before the first use of the nanomaterial after 1 January 2026. Legacy labels may be retained for bulk stocks that are not re‑labelled, provided a compliant SDS is available.

Q4: What PPE is recommended for handling nanomaterial powders? A: At minimum, use a fitted respirator (N95 or higher), nitrile gloves with a thickness of at least 0.1 mm, and a lab coat made of tightly woven fabric. Additional eye protection is advised when aerosol generation is possible.