Acrylonitrile-butadiene copolymer (NBR) is an emulsion-polymerised elastomer in which the bound acrylonitrile content controls the balance between resistance to aliphatic hydrocarbon fluids and low-temperature flexibility. Commercial grades are usually supplied between 18% and 50% acrylonitrile content; raw-polymer Mooney viscosity ML(1+4) at 100°C typically falls between 30 and 95 MU when determined to ISO 289-1. The elastomer is designated as NBR under ASTM D1418 and evaluated under ISO 4658. In oil-contact service, a grade with higher acrylonitrile content shows lower volume swell in ASTM IRM 903 oil when tested to ASTM D471 or ISO 1817; a grade at the lower end of the acrylonitrile range is used where low-temperature sealing performance dominates. For a 2026 EU import, the regulatory file must first identify whether the shipment is a bulk polymer, a compounded mixture, or a finished article, because that classification determines whether registration, SVHC, SCIP, and Annex XVII duties attach.

EU REACH Compliance Checklist for NBR Imports: SVHC, SCIP and Annex XVII in 2026

The first control point is legal classification. A raw NBR bale is normally a polymer and therefore a substance under REACH Article 3(1); as a polymer it benefits from the registration exemption in Article 2(9). A compounded NBR masterbatch may be a mixture if additives are intentionally incorporated. A cured NBR gasket, hose, or glove is an article under Article 3(3) when its shape, surface, or design determines its function more than its chemical composition does. Bulk polymer imports do not trigger SCIP notification, but they are not outside Annex XVII restriction screening; restrictions apply directly to substances, mixtures, and in some entries to articles regardless of polymer status. The monomers 1,3-butadiene and acrylonitrile are separately regulated if placed on the EU market as such and are subject to Candidate List obligations when present in articles.

The compliance checklist for imported NBR in 2026 must include candidate-list screening of every substance that may remain from polymerisation or enter during compounding. 1,3-Butadiene (EC 203-450-8, CAS 106-99-0) and acrylonitrile (EC 203-466-5, CAS 107-13-1) are Candidate List SVHCs because of their harmonised CMR classifications under CLP Annex VI. Consequently, a cured NBR article containing more than 0.1% w/w residual monomer by article mass triggers automatic communication duties under Article 33(1) of REACH and SCIP notification under Article 9(1)(i) of Directive 2008/98/EC. Importers must also screen plasticisers, antidegradants, emulsifier residues, vulcanisation accelerators, and any added masterbatch. Candidate List phthalates such as DEHP, DBP, BBP, and DIBP are still encountered in older NBR plasticiser systems and must be verified when the finished article is placed on the EU market.

Supplier documentation must move beyond a generic “REACH compliant” statement. The importer should require a formulation disclosure with CAS numbers, residual monomer certificates, CLP classifications, and batch-specific analytical data. The disclosure must state whether each Candidate List substance is present above 0.1% w/w in the finished article, identify the annex entries relevant to each restricted substance, and confirm the market segment for which the article is placed on the market. Commercial confidentiality can be handled through third-party inspection or a redacted dual-column disclosure, but the underlying compliance data must be available for customs or market surveillance authorities. Without batch-specific residual monomer data, the EU importer carries the regulatory risk of placing an unassessed NBR article on the market.

Does the 0.1% w/w SVHC Threshold Apply to Each NBR Article or to the Complete Assembly?

The 0.1% w/w trigger is applied at the level of each individual article as supplied, not to an entire complex product. The Court of Justice of the European Union in Case C-324/14 confirmed that a complex product containing multiple articles is assessed component by component. For a fuel hose assembly containing an NBR inner tube, a textile reinforcement, and an NBR outer cover, the importer must assess each distinct article separately and cannot average SVHC concentration across the assembly. This interpretation increases the need for component-level formulation data from the non-EU producer. A moulded NBR gasket with no other assembled component is assessed as one article; a control-valve assembly containing the same gasket is assessed at the gasket level when supplied as part of the assembly.

SCIP reporting for NBR articles is not a single notification for the general polymer class. The notification must identify the article category, the material type as an elastomer or rubber material, each Candidate List substance, the concentration range in the article, and safe-use information related to handling, disposal, or maintenance. The duty falls on the EU legal entity that first places the article on the market; a non-EU NBR fabricator cannot submit directly. Importers of finished NBR seals, industrial gloves, gaskets, and fuel components must therefore require supplier SCIP data packages before shipment and verify that the submitted information corresponds to the actual production lot. If an NBR article contains no SVHC above 0.1% w/w, no SCIP notification is required, but the absence must be supported by test data because residual monomer content can vary between production campaigns.

Article 33(1) requires an automatic communication to industrial recipients when an NBR article contains an SVHC above 0.1% w/w. The communication must include the substance name, CAS or EC number, and available safe-use information. Under Article 33(2), a consumer must receive the same information within 45 days of a request. For NBR articles distributed through distributors, the importer should pass the information through the supply chain: the direct recipient is the distributor, and the distributor must forward it if downstream customers are identified. A safety data sheet is generally not required for articles, but an SVHC disclosure is not an SDS substitute.

When Annex XVII Restriction Entries Apply to Residual Butadiene and Acrylonitrile

Annex XVII of REACH is a consolidated restriction list that applies independently of the polymer registration exemption. Importers must screen the formulation against the version applicable on the date of import. Entry 28, Entry 29, and Entry 30 control CMR Category 1A or 1B substances in substances, mixtures, and articles supplied to the general public under defined concentration limits. Because 1,3-butadiene is classified Carc. 1A, Muta. 1B, and acrylonitrile is classified Carc. 1B under CLP Annex VI, residual monomer levels must be compared with the applicable CLP generic concentration limits and any specific concentration limits in CLP Annex VI. For industrial NBR articles, the restriction scope may be narrower, but Article 33 SVHC communication remains independent of market segment.

Annex XVII screening must also include additives. Phthalate plasticisers such as DEHP, DBP, BBP, and DIBP are restricted under Entry 51 in toys and childcare articles at 0.1% w/w in plasticised material; if an NBR article is intended for a childcare application, the plasticiser system must be verified accordingly. Lead-based stabilisers or lead-containing pigments fall under Entry 63, which restricts lead in articles or accessible parts supplied to the general public. The formulation disclosure must list each restricted substance by CAS number and provide the residual or migrating concentration in the final article. A declaration that simply states “REACH compliant” is insufficient for import documentation.

The Annex XVII check should be performed as a chemical-by-chemical query against the consolidated restriction list. For each intentional additive and residual monomer, the importer must record the CAS number, the CLP Annex VI classification, the concentration in the article or mixture, and the market segment. If a restricted substance exceeds an entry-specific limit, the restriction applies regardless of whether the substance is an impurity or an intentional additive unless the entry expressly excludes impurities. For NBR, the main candidate residues are monomers; for compounded NBR, plasticisers and curatives are equally important. The compliance file should include the restriction status even for substances below the limit, because the absence of a finding is part of the due-diligence record.

Residual monomer verification requires a headspace gas-chromatographic method with a limit of quantification below the 0.1% w/w decision threshold. Headspace gas chromatography with mass-selective detection is used for residual acrylonitrile in NBR according to ISO 4581; for 1,3-butadiene, the same volatile-monomer headspace approach is applicable because the monomer is thermally released from the polymer matrix under controlled vial equilibration. A laboratory accredited to ISO/IEC 17025 should report the method limit of quantification and the sampling plan. An LOQ of 0.01% w/w or lower is operationally preferable to provide analytical margin below the SVHC communication trigger. Batch-average certificates are not sufficient: emulsion polymerisation and subsequent steam stripping can produce residual monomer variation across bales, and the analytical sample must be taken from the final article when the import is a cured NBR component.

NBR is produced by free-radical emulsion polymerisation, usually in cold conditions between 5°C and 15°C for standard grades, or in hot systems between 30°C and 50°C for specific lower-Mooney or branched microstructures. Residual monomer content is controlled by steam stripping and vacuum devolatilisation. Batch-to-batch variation in residual acrylonitrile is influenced by reactor conversion, stripping absolute pressure, and coagulation pH. These processing variables are the reason compliance documents cannot rely on generic typicals. A high-conversion grade is not necessarily safer: residual monomer removal depends on downstream separation. The bound acrylonitrile content is commonly determined by nitrogen analysis to ISO 1656, but that method does not measure free residual acrylonitrile; free monomer requires headspace gas chromatography.

For NBR latex imports, the product is a substance or mixture, not an article. Registration may be required for the monomers if imported as such, but the polymer itself remains exempt. The latex importer must still verify that the stabiliser, biocide, and residual monomer composition does not contain restricted substances under Annex XVII when the latex is placed on the market as a substance or mixture. The dipped-article producer inside the EU is the entity responsible for SCIP notification if the produced gloves or films contain SVHC above 0.1% w/w; the latex importer should nevertheless provide residual monomer data to allow downstream compliance.

In practice, high-acrylonitrile NBR grades are specified for gaskets and oil seals in hydraulic and automotive systems because of lower volume swell in ASTM IRM 903 oil. Low-acrylonitrile grades are used for static sealing at low temperatures and for vibration-damping components where low-temperature flexibility outweighs oil resistance. Carboxylated NBR (XNBR) is a separate copolymer with an unsaturated carboxylic acid termonomer; it is not covered by the basic NBR designation and has its own compounding and compliance profile. Importers should ensure that the product’s actual registered trade name and CAS number match the technical datasheet; blends with PVC or other polymers must be described as mixtures, not as NBR alone.

For compounding and processing, acrylonitrile content influences both performance and residual monomer control. High-acrylonitrile grades require more intensive stripping during polymerisation; process records showing reduced steam stripping or shortened vacuum devolatilisation can indicate elevated residual acrylonitrile. Compounds are mixed in an internal mixer with dump temperatures between 100°C and 140°C. Sulfur-cured NBR compounds are then cooled on a two-roll mill below 90°C to limit scorch, with Mooney scorch measured at 121°C to ISO 289-2. Peroxide-cured NBR compounds are used for lower compression set in coolant and hot-water seals; they must avoid amine-based antidegradants that interfere with peroxide crosslinking. Carbon black types such as N550 and N774 are typical reinforcement grades, and their type, loading, and trace impurity profile must be listed in the compliance file because the filler and plasticiser package influence the final article’s SVHC and Annex XVII screening.

Mechanical and fluid-resistance tests are not regulatory thresholds but are part of the technical file required for supplier qualification. Tensile stress-strain is measured to ISO 37, compression set to ISO 815-1, and fluid immersion to ISO 1817 or ASTM D471. A peroxide-cured NBR compound may show compression set values below 15% after 24 h at 100°C, while sulfur-cured NBR can exceed 25% depending on filler and post-cure; these values are compound-specific and must be verified for each imported lot. NBR is not suitable for continuous exposure to aromatic hydrocarbons, ketones, or strong polar solvents, and outdoor service requires antiozonant protection. These operational boundaries are part of the compliance record because a failed NBR article that requires early replacement may be considered a different article in the SCIP database when the replacement article is placed on the market.