What changed—and what a SNUR means
EPA’s activity record reports that a final rule for a particular multi-walled carbon-nanotube substance became effective on 22 September 2026, following publication on 24 July 2026.
A significant new use rule, or SNUR, identifies uses of a covered chemical that require advance notification. The significant new use notice, or SNUN, is the submission EPA reviews before that activity starts. The effective date makes this a current sourcing question, not evidence that every nanotube formulation is prohibited or unsafe.
Match the chemical, then examine the proposed use
“Multi-walled carbon nanotube” names a material family. It does not establish whether a purchased masterbatch contains the substance covered by this rule. A product name or generic safety data sheet can leave that crucial link unresolved.
Ask the supplier to connect its product to the relevant substance identity and TSCA documentation. Compare that evidence with the final rule’s exact identity and significant-use provisions. If confidentiality prevents a direct match, arrange qualified regulatory review through an appropriate disclosure channel.
A filler substitution changes the screening question
Consider the proposed switch from a conventional conductive filler to a nanotube masterbatch for injection-moulded housings. The housing’s purpose may stay the same while the chemical and handling route change. Describe formulation, concentration, processing, exposure controls and waste handling rather than assuming an existing approval transfers.
The following branches guide planning; they are not findings about this proposed housing.
| Evidence available | Next manufacturing decision |
|---|---|
| Identity matches; the intended activity is designated significant. | Pause that activity and address notification and EPA review before starting it. |
| The comparison supports no trigger under this SNUR. | Record the basis, check other applicable obligations, and then schedule engineering qualification. |
| Identity or use conditions remain ambiguous. | Keep the trial commitment provisional and obtain specialist clarification; do not assume a favourable outcome. |
Keep legal applicability separate from engineering qualification
A conductive housing can pass a performance test while its chemical-use status remains unresolved. Conversely, an applicable regulatory pathway does not demonstrate that the part meets the required conductivity or mechanical performance.
Once the route is established, evaluate candidate formulations for the same housing duty and acceptance goals. If a sample falls short, adjust the formulation or consider another filler; screen any resulting substance or process change again. For candidates that meet the goals, compare complete delivery needs, including validation, processing, maintenance and supply documentation. Exposure, cost and performance remain project-specific.
Build a supplier brief that supports a real decision
Bring the intended housing geometry, required quantity, performance targets and launch plan together with the records below. This gives the supplier and regulatory adviser enough context to distinguish an ordinary qualification task from a notification question—and identify what must be resolved before procurement, import or process trials.
- Supplier and product names, plus substance identity that can be disclosed.
- Current SDS and a TSCA status statement linked to the offered material.
- Proposed formulation, filler concentration and annual volume.
- Processing method and the worker-exposure controls actually planned.
- End-use description, import arrangements and waste-handling route.
- Electrical and structural acceptance criteria, together with a proposed test plan.
Frequently asked questions
Does a supplier’s assurance cover a later change in handling?
Ask what activity the assurance addresses. Moving from supplied pellets to a different handling or processing route can change the comparison with the rule; obtain an updated assessment rather than carrying the original conclusion forward.
Can a small trial be treated as automatically exempt?
Trial size alone is not a reliable answer. Have the proposed activity and any claimed exemption evaluated against the applicable provisions before allocating material to the trial.
What if the supplier cannot disclose the chemical identity to our engineering team?
As a project-coordination step, engineering can give the authorised reviewer the intended process and import arrangements tied to the supplier’s offered product, while the supplier provides confidential identity information through an appropriate channel. Seek an assessment of whether that specific material and proposed activity match the rule, identifying unresolved points that affect purchasing or sample-trial scheduling. Where identity remains unclear, qualified regulatory review is still needed. Use the assessment to resolve those dependencies before committing; a finding that this SNUR is not triggered does not establish overall project compliance. This handover is a practical recommendation, not an additional statutory document or filing requirement.