Rubber Product Manufacturing for Mechanical Use (U.S., NAICS 326291)

An investor's primer — relevant to both public-market and private investors.

1. Overview

This industry makes the molded, extruded, and precision-cut rubber parts that let machines run without leaking, rattling, or wearing out — O-rings, engine and equipment mounts, bushings, grommets, boots, weatherstrip, molded seals, and similar "mechanical rubber goods." [1] Production typically runs from compound formulation and internal mixing through molding or extrusion, vulcanization in presses, autoclaves, or hot-air systems, and then trimming, grinding, inspection, and testing. [2] These are unglamorous parts, usually costing pennies to a few dollars each, but a modern car, jet, pump, or semiconductor tool cannot function without hundreds of them. That combination — low unit price, high criticality, and heavy repeat demand — is what makes the sector interesting to an investor.

Two things define the opportunity. First, it is real domestic manufacturing, not a paper or gig industry: roughly 328 U.S. firms turning out about $7.7 billion of product a year, employing some 27,000 people. [3][4] Second, it is fragmented — the four largest producers hold under a third of U.S. revenue [4] — which means the sector is consolidating and much of it is privately held.

Ways in. There is no large U.S.-listed company that does only NAICS 326291. Public investors get exposure through diversified motion-and-control and auto-parts firms where rubber sealing is one line among many (Parker Hannifin, Cooper Standard, Gates, EnPro) or through foreign-listed specialists (Trelleborg, Continental, several Japanese makers). Private investors — the more natural fit here — buy the custom molders directly, a lower-middle-market niche that private-equity roll-ups and independent buyers are actively acquiring as founder-owners retire. [20]

2. What it is and how it is structured

Scope. NAICS (North American Industry Classification System) code 326291 covers establishments that make rubber goods for mechanical use by molding, extruding, or lathe-cutting — typically parts for motor vehicles, machinery, and equipment. [1] Think engine mounts and anti-vibration isolators, O-rings, molded rubber-to-metal bonded components, extruded profiles and weatherstrip, and lathe-cut washers and spacers. Much of the business is build-to-print or co-engineered rather than commodity conversion — the compound, tooling, tolerances, rubber-to-substrate bond, and validation protocol are tailored to an application. Automotive suppliers may design and validate a component, receive a vehicle-platform award, build tooling, and supply the part for the platform's production life (typically five to eight years, although sourcing awards do not guarantee volume). [5]

What it excludes (adjacent codes). The rubber-parts family is deliberately split across several NAICS codes, so no single code equals the whole activity:

• 326211 — tires and inner tubes.
• 326220 — rubber and plastic hoses and belting (this is where Gates's belts and hydraulic hose sit, not 326291). [6]
• 339991 — gaskets, packing, and sealing devices of all materials (oil seals, grease seals, molded packings). Because rubber seals can be classified here or in 326291, the line between the two is blurry, and most sealing companies report across both. [7]
• 326299 — all other rubber products (floor mats, balloons, tubing, latex foam). [7]

Commercial market reports routinely combine these categories and therefore overstate the addressable market for 326291. [8]

Ownership mix. Federal data count U.S. establishments, and those establishments are overwhelmingly small-to-mid-size manufacturers — averaging about 73 employees and roughly $23 million of revenue per firm. [3][4] But the largest plants on U.S. soil are frequently the American operations of foreign parents — Germany's Freudenberg and Continental, Sweden's Trelleborg, France's Hutchinson, and several Japanese groups — whose global scale dwarfs their 326291 slice. The Association for Rubber Products Manufacturers describes its membership as ranging from small producers to multibillion-dollar conglomerates, consistent with this barbell structure. [9] The ownership picture is therefore a long tail of independent domestic molders under a handful of much larger multinationals.

3. How big it is

Federal statistics (our ground-truth figures):

The HHI (Herfindahl-Hirschman Index, the sum of squared market shares; the U.S. Department of Justice treats anything under 1,500 as "unconcentrated") of 334 confirms a fragmented market with no dominant player. [4]

Product mix. Census's 2016 manufacturing-and-trade report placed industry product shipments at $6.48 billion, with molded automotive goods contributing $3.43 billion and extruded automotive goods (excluding tubing) another $652 million — together 62.9% of reported shipments. Other transportation and off-highway molded goods added $906 million, other molded goods $627 million, other extruded goods $237 million, and lathe-cut goods $242 million. [11] This confirms automotive as the industry's largest end market by a wide margin.

Undercount caveat. These figures are honest but partial in two ways. (1) They capture only U.S. production classified to this one code; the broader economic activity of "mechanical rubber goods" also lives in codes 339991 and 326220, so any single company's sealing business usually straddles boundaries and the true market for these products is larger than $7.7 billion. Broader "gaskets and seals" market estimates (a wider, all-materials, global definition) run into the tens of billions of dollars. [12][13] (2) The largest global players' U.S. plants are counted, but their headline global revenues (Freudenberg ~€11.9 billion group; Trelleborg's U.S. sealing unit alone ~$520 million) sit mostly outside this narrow code. [14][15] This is not, however, a government-dominated or micro-operator industry — the federal counts are a fair picture of the genuine domestic manufacturing footprint.

4. The investable universe

There is no pure-play U.S.-listed company confined to NAICS 326291. The table below shows the most relevant public names (all of whom span adjacent codes) plus the major private and foreign owners. Tickers and scale are for orientation, not recommendations.

Trelleborg's competitor disclosure also names Diploma, Federal-Mogul, Fenner, Saint-Gobain, TransDigm, Wolverine, Datwyler, Greene Tweed, and SKF as relevant players in the broader engineered-elastomers space. [18]

For most investors, the practical takeaway: public equity gives diluted exposure (rubber sealing is a minority of any listed name's revenue), while the concentrated exposure sits in private hands — the hundreds of independent custom molders that make up the bulk of the 328 U.S. firms. [4]

5. How the money works

Owners in this business make money the way most engineered-components manufacturers do — on the spread between input cost and selling price, multiplied by how hard they run their plants.

• Input-cost spread. The main raw materials are natural rubber and synthetic elastomers — EPDM (ethylene propylene diene monomer, used in weatherstrip and coolant seals), NBR/nitrile (oil and fuel resistance), silicone, and high-performance fluoroelastomers (FKM/Viton, FFKM) — plus carbon black, process oils, resins, curatives, and purchased metal and plastic components. [19][23] Material is a large share of cost — Cooper Standard reported direct materials at approximately 52% of its 2025 cost of products sold [5] — so gross margin lives or dies on the ability to pass rubber-price swings through to customers, usually with a lag. Commodity-indexed supplier and customer agreements reduce some exposure, but recovery can be partial or delayed. When natural-rubber or feedstock prices spike, margins compress until price adjustments catch up. [19][23]
• Capacity utilization. Molding presses and extrusion lines are capital assets; profitability rises sharply as utilization climbs and fixed costs spread over more parts. Scrap rates, cure yield, rework, and cycle times are the operational levers. Cooper Standard reported $43.4 million of 2025 manufacturing and purchasing savings in Sealing Systems, partly offset by $12.9 million of labor inflation and $5.7 million of other operating-cost increases. [5]
• Tooling and design-in stickiness. Custom parts carry upfront tooling/mold costs and a qualification process. Once a part is designed into a customer's product and validated, switching suppliers is costly and slow — especially in aerospace, semiconductor, and medical uses. That creates durable, repeat revenue and pricing power on qualified parts.
• The value pyramid. Commodity extrusion and simple O-rings compete on price and are exposed to low-cost imports, so margins are thin. Engineered, qualified, or exotic-material parts (fluoroelastomer seals for semiconductor fabs, aerospace-spec components, nuclear and food/pharma seals) carry much fatter margins. The margin dispersion across public comparables illustrates this: Cooper Standard's Sealing Systems segment produced $1.42 billion of 2025 sales and $136 million of adjusted segment EBITDA (9.6% margin), while Enpro's more specialized Sealing Technologies segment generated $732 million of sales and $241 million of adjusted segment EBITDA (32.9% margin). [5][17] Trelleborg's broader global Sealing Solutions reported a 20.3% EBITA margin, with only 33% of segment sales in the Americas. [18]
• OEM vs. aftermarket mix. Original-equipment (OEM) volume is cyclical and price-pressured by large buyers; aftermarket/replacement demand is steadier and higher-margin because these are wear parts that must be replaced over an asset's life. Suppliers with heavy replacement mix (e.g., Gates) enjoy more stable earnings. [6]

The short version: a well-run molder earns a modest but steady margin on high-volume commodity work and a premium on engineered, designed-in parts — and grows free cash flow by keeping presses full and passing raw-material costs through. Cooper Standard's 2025 gross margin increased to 11.9% from 11.1%, helped by purchasing and manufacturing savings but held back by unfavorable volume and mix, labor inflation, and overhead costs. [5]

6. What drives demand

• Vehicle production. The single biggest driver. Every vehicle contains hundreds of rubber parts — seals, weatherstrip, mounts, bushings, boots, grommets. Output tracks global light-vehicle build rates. The 2016 Census product mix — 62.9% explicitly automotive molded or extruded goods — confirms the industry's underlying vehicle exposure. [11][13]
• The EV transition. A mix shift more than a threat: electric vehicles drop some engine-specific parts but add battery-pack and thermal-management seals, and demand new anti-vibration and noise-vibration-harshness (NVH) isolators tuned to electric drivetrains (different frequencies, lighter/compact designs). Conversely, engine, fuel-system, and some conventional powertrain rubber content declines. Net effect on rubber content per vehicle is judged neutral-to-positive. [24] Thermoplastic elastomers and other lightweight systems can substitute for conventional EPDM or rubber-metal designs; Cooper Standard, for example, markets its FlexiCore thermoplastic body seal as a lighter, recyclable alternative. [25]
• Industrial production and capex. Pumps, compressors, hydraulics, and machinery all consume seals and mounts; demand rises and falls with the industrial cycle.
• Aerospace and defense build rates, and semiconductor fab investment (fluoroelastomer seals are critical inside chip-making equipment). Trelleborg reported strong 2025 aerospace demand but weaker automotive deliveries, particularly in Europe, and is directing investment toward aerospace, semiconductors, industrial automation, and processing industries. [18] Enpro reported strong 2025 demand in aerospace, oil and gas, food and biopharma, and domestic general industrial applications, offset by weak North American commercial-vehicle OEM demand and slow international industrial markets. [17]
• Oil & gas, chemical processing, and medical/pharma — each demands specialty elastomers and drives the high-margin end.
• Aftermarket replacement. A steady baseline: rubber parts age, harden, and fail, generating recurring replacement demand independent of new-build cycles.
• Automation and design efficiency. Trelleborg introduced automated cells for complex rubber-metal components and reported that AI-assisted processes shortened some design cycles by as much as 30%, pointing to automation and simulation as both cost and development-time levers for competitive advantage. [18]
• Nearshoring. A potential tailwind, but not effortless. The Association for Rubber Products Manufacturers' 2025 industry discussion described greater input-price volatility, reduced domestic polymer and rubber-chemical production, sourcing difficulty, and increased interest in nearshoring or reshoring — accompanied by meaningful required investment. [26]

7. Regulation

• PFAS and fluoroelastomers — the key regulatory wildcard. Regulators in the U.S. (EPA reporting under the Toxic Substances Control Act) and the EU (a proposed universal PFAS restriction under REACH) are moving to classify fluoroelastomers — FKM/Viton, FFKM, fluorosilicone — as PFAS ("per- and polyfluoroalkyl substances"). [27] EPA's TSCA rule requires reporting by covered manufacturers and importers of PFAS or PFAS-containing articles, although EPA has proposed scope changes and extended reporting dates. [28] 3M's decision to exit fluoropolymer production by end-2025 has already stoked supply and cost concerns, and there is no drop-in replacement for these materials in the most demanding aerospace and semiconductor seals. [27] Trelleborg's launch of a PFAS-free elastomer for semiconductor applications shows that reformulation is already a competitive and compliance issue. [29] This is both a cost/supply risk and, for suppliers with secured material, a potential pricing tailwind.
• Chemical and materials rules. EU REACH and RoHS, California Proposition 65 warnings, and substance-of-concern reporting shape compounding choices.
• Application-specific standards. Food-contact rubber (FDA 21 CFR 177.2600), medical (USP Class VI, ISO 10993), automotive quality (IATF 16949), aerospace (AS9100), and nuclear/pressure standards act as qualification gates that both raise costs and protect incumbents.
• Environmental and workplace. EPA air permits for volatile-organic emissions from mixing and curing, and OSHA exposure limits for process fumes and dust. EPA identifies mixing, extrusion, curing, grinding, and related finishing as potential emission points. [2] OSHA prescribes guarding, trip controls, and stopping-distance requirements for mills and calenders (29 CFR 1910.216). [30] Note: the EPA Rubber Tire Manufacturing NESHAP governs tire manufacturing specifically and should not be generalized to mechanical rubber goods without checking a facility's actual processes, emissions, and permits. [31]
• Workplace safety. BLS reported a 2024 total-recordable injury rate of 2.5 cases per 100 full-time-equivalent workers for NAICS 326291, including a DART (days away, restricted, or transferred) rate of 1.5. [32]
• Trade. Section 301 tariffs on Chinese-made rubber parts and broader 2025 tariff uncertainty affect both imported competition and exported product. [20]

8. Competitive dynamics and consolidation

The market is a two-tier structure. At the top sit a handful of large, diversified strategics — Parker, Continental, Freudenberg, Trelleborg, Hutchinson, and the Japanese auto-rubber groups — that win multi-year OEM programs on engineering and global footprint. Below them is a long fragmented tail of regional custom molders competing on price, speed, and service (CR4 just 29.5%, HHI 334). [4]

Consolidation is the through-line. Because most of the tail is privately owned by aging founders, the sector is prime territory for private-equity roll-ups: platforms such as Marco Rubber & Plastics (backed by Align Capital) have executed a string of add-on acquisitions in custom sealing and seal distribution, and strategics continue to buy capacity. [20] Trelleborg's 2022 acquisition of Minnesota Rubber & Plastics provides a transaction reference: it paid $950 million (cash- and debt-free basis) for a business with approximately SEK 2.25 billion of annual sales and disclosed trailing EBITA and EBITDA margins of approximately 21% and 24%, though the target included plastics and medical applications beyond 326291. [33][34] Competition on commodity parts is intense and import-exposed; competition on engineered, qualified parts turns on design-in relationships and switching costs rather than price.

9. Risks

• Raw-material and energy volatility. Rubber, feedstock, carbon-black, and process-chemical price swings squeeze margins until prices reset. Carbon-black feedstocks include fuel oils, coal-tar distillates, and ethylene-cracker residue, whose cost and availability vary by geography. [35] Natural rubber adds weather, disease, geopolitical, and import-supply risks. [19][23]
• Automotive cyclicality and customer concentration. Auto-exposed suppliers ride the vehicle cycle and negotiate against a few powerful OEM buyers who push for annual price givebacks — a structural margin headwind for names like Cooper Standard, where Ford, GM, and Stellantis together represent 56% of sales. [5]
• EV transition execution. A mis-timed bet on the wrong content mix, or lost ICE-specific volume before EV volume arrives, can hurt.
• PFAS regulation on fluoroelastomers — supply disruption and cost inflation for the highest-value seal lines. [27][28]
• Import substitution. Low-cost overseas producers pressure commodity O-rings and extrusions.
• Labor and capital intensity. Plants need compounders, press and extrusion operators, setup technicians, trimmers, inspectors, maintenance workers, and tooling and process engineers. Skilled-labor availability, wage inflation, and the upfront tooling burden on custom programs are ongoing pressures. Automation can reduce direct labor and improve repeatability but raises capital requirements and the need for controls and maintenance skills.
• Workplace hazards. Exposure includes hot presses, mills, calenders, dusts, solvents, and rubber-processing chemicals — reflected in the industry's 2.5 per 100 FTE injury rate. [32]
• Legacy liabilities. Some long-established sealing makers carry historical environmental or product-liability exposure (asbestos-era litigation, for example, in older gasket lines). Environmental liabilities include compounding dust, volatile and hazardous air emissions, solvent handling, waste rubber, wastewater from cooling and cleaning, chemical storage, and legacy soil or groundwater contamination. [2]

10. How to invest and the outlook

Public routes. No U.S.-listed pure-play exists, so exposure is diluted:

• Cooper Standard (CPS) is the closest listed proxy for automotive rubber sealing — but it is a small-cap, cyclical, and leveraged post-restructuring name with high customer concentration. [5]
• Parker Hannifin (PH) offers high-quality, diversified exposure where seals are a small, profitable slice of a much larger motion-and-control franchise. [16]
• Gates (GTES) provides belt-and-hose (adjacent 326220) exposure with an attractive replacement-heavy revenue base. [6]
• EnPro (NPO) is the way to own high-margin engineered sealing (mostly 339991). [17]
• Foreign-listed specialists — Trelleborg (Stockholm), Continental (Frankfurt), Datwyler, SKF, and Sumitomo Riko / Toyoda Gosei / NOK / Nishikawa (Tokyo) — offer more concentrated sealing/anti-vibration exposure for investors comfortable with overseas listings. [15][18][21][22]
• There is no dedicated ETF; broad auto-parts or industrial funds are the indirect route.

Private routes — where the concentrated exposure actually lives. The 300-plus independent U.S. custom molders are mostly for sale over time as owners retire. Options range from directly acquiring a molder (lower-middle-market, often succession-driven deals), to backing a PE platform or independent sponsor running a roll-up, to distribution plays consolidating seal supply. [20] Private-equity diligence should focus on customer and platform concentration, tooling ownership, qualification and switching barriers, compound intellectual property, raw-material pass-through mechanics, utilization and bottlenecks, scrap and rework, launch performance, maintenance capital expenditure, environmental history, and the proportion of recurring replacement or aftermarket revenue. A seller described simply as a "rubber seals company" should be mapped product by product: a substantial portion may belong in 339991, 326220, or 326299 rather than 326291.

Near-term drivers and outlook (forward-looking judgment). Expect low-single-digit organic growth tracking industrial production and vehicle builds, not a boom. The EV transition looks net-neutral-to-positive for rubber content per vehicle. Reshoring and supply-chain resilience should favor domestic molders on critical, qualified parts. The genuine swing factor is PFAS regulation on fluoroelastomers: it could tighten supply and lift prices/margins for makers with secured material, or force costly reformulation for those without. Margins will stay highest in engineered niches (aerospace, semiconductor, medical) and thin in commodity extrusion, and consolidation of the fragmented private base is likely to continue — the clearest structural opportunity for private capital.

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Sources

1. NAICS Association. "NAICS Code 326291 — Rubber Product Manufacturing for Mechanical Use." 2022. https://www.naics.com/naics-code-description/?code=326291
2. U.S. Environmental Protection Agency. "Rubber Products Manufacturing — Process Description and Emissions." https://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=P100RGEV.TXT
3. U.S. Census Bureau. "County Business Patterns (NAICS 326291)." 2023. https://www.census.gov/programs-surveys/cbp.html
4. U.S. Census Bureau. "2022 Economic Census — Concentration Ratios and Selected Statistics, NAICS 326291." 2022. https://www.census.gov/programs-surveys/economic-census.html
5. Cooper Standard Holdings. "Form 10-K for Fiscal Year 2025." SEC Filing. https://www.sec.gov/Archives/edgar/data/1320461/000132046126000012/cps-20260213.htm
6. Wikipedia. "Gates Corporation (Power Transmission and Fluid Power segments; ticker GTES)." 2026. https://en.wikipedia.org/wiki/Gates_Corporation
7. IBISWorld. "NAICS 339991 Gasket, Packing, and Sealing Device Manufacturing; NAICS 326299 All Other Rubber Product Manufacturing; NAICS 326220 Rubber and Plastics Hoses and Belting." 2025. https://www.ibisworld.com/classifications/naics/339991/gasket-packing-and-sealing-device-manufacturing/
8. U.S. Census Bureau. "NAICS Classification and Cross-References (Sector 31-33)." https://www.census.gov/naics/resources/archives/sect31-33.html
9. Association for Rubber Products Manufacturers. "About ARPM." https://arpminc.com/about/
10. U.S. Small Business Administration. "Table of Small Business Size Standards (NAICS 326291 — 750 employees)." 2023. https://www.sba.gov/document/support-table-size-standards
11. U.S. Census Bureau. "2016 Manufacturing and International Trade Report." https://www.census.gov/foreign-trade/Press-Release/MITR/2016/2016_Manufacturing_and_International_Trade_Report.pdf
12. Polaris Market Research. "Gaskets and Seals Market Size, Share & Forecast." 2025. https://www.polarismarketresearch.com/industry-analysis/gaskets-and-seals-market
13. The Business Research Company. "Automotive Gaskets and Seals Global Market Report." 2026. https://www.thebusinessresearchcompany.com/report/automotive-gaskets-and-seals-global-market-report
14. Freudenberg Group. "Freudenberg Sees Strong Earnings Growth (FY2024 sales €11.9B; Sealing Technologies)." 2025. https://www.freudenberg.com/en/company/press-media/news-detail/2025-03-20-freudenberg-sees-strong-earnings-growth
15. Trelleborg AB. "Annual Report 2024 (Sealing Solutions; U.S. unit revenue)." 2024. https://www.trelleborg.com/-/media/group/about-us/agm/2025/en/trelleborg-annual-report-2024.pdf
16. Parker Hannifin Corporation. "Fact Sheet and FY2024 Annual Report (sales ~$19.9B; O-Ring & Engineered Seals Division)." 2024. https://www.parker.com/content/dam/Parker-com/About-Us/Literature/PH-AR-FY24.pdf
17. Enpro Inc. "Form 10-K for Fiscal Year 2025 (Sealing Technologies segment)." SEC Filing. https://www.sec.gov/Archives/edgar/data/1164863/000162828026009798/npo-20251231.htm
18. Trelleborg AB. "Annual Report 2025 (Sealing Solutions segment; competitor disclosure)." 2025. https://www.trelleborg.com/-/media/group/about-us/agm/2026/en/trelleborg-annual-report-2025.pdf
19. IMARC Group. "EPDM Rubber Prices — Price Chart and Trend." 2026. https://www.imarcgroup.com/epdm-rubber-pricing-report
20. Rubber News / Align Capital Partners / Plastics Today. "Rubber Industry 2025 Mergers and Acquisitions; Marco Rubber & Plastics roll-up; Plastics Industry M&A Surges in 2025." 2025. https://www.rubbernews.com/company-moves/mergers-acquisitions/rn-rubber-industry-2025-mergers-acquisitions/
21. Continental AG. "ContiTech industrial products and Vantage hose launch (conveyor belts, air springs, vibration control, hoses)." 2025. https://www.continental.com/en/press/press-releases/251111-vantage-hoses/
22. MarketsandMarkets / Intel Market Research. "Automotive Rubber Seals and Weatherstrip Seal Market (Cooper Standard, Hutchinson, Toyoda Gosei, Nishikawa, SaarGummi)." 2025. https://www.marketsandmarkets.com/ResearchInsight/automotive-window-exterior-sealing-system-market.asp
23. Statista / FAO. "Rubber price per kilogram and world rubber consumption by type." 2025. https://www.statista.com/statistics/727582/price-of-rubber-per-pound/
24. Market Research Future / Global Growth Insights. "Automotive Anti-Vibration Mounting and Anti-Vibration Rubber Mounts Market (EV mount requirements)." 2025. https://www.marketresearchfuture.com/reports/automotive-anti-vibration-mounting-market-38227
25. Cooper Standard Holdings. "Form 10-K for Fiscal Year 2024 (FlexiCore thermoplastic body seal)." SEC Filing. https://www.sec.gov/Archives/edgar/data/1320461/000132046125000033/cps-20241231.htm
26. Association for Rubber Products Manufacturers. "2025 Industry Publication (nearshoring, input volatility)." https://publications.bigredm.com/flipbook/ARPM/2025/Issue3/
27. Apple Rubber / The Rubber Group. "PFAS Use in the Rubber Industry and New Regulations; Fluoroelastomer Supply Threatened by PFAS Classification (3M fluoropolymer exit)." 2025. https://www.applerubber.com/hot-topics-for-engineers/pfas-use-in-the-rubber-industry-and-new-regulations/
28. U.S. Environmental Protection Agency. "TSCA Section 8(a)(7) Reporting and Recordkeeping Requirements for PFAS." https://www.epa.gov/assessing-and-managing-chemicals-under-tsca/tsca-section-8a7-reporting-and-recordkeeping
29. Trelleborg Sealing Solutions. "Accelerating by Scaling Up (PFAS-free elastomer launch)." https://www.trelleborg.com/en/about-us/organization/business-areas/trelleborg-sealing-solutions/accelerating-by-scaling-up
30. U.S. Occupational Safety and Health Administration. "29 CFR 1910.216 — Mills and Calenders in the Rubber and Plastics Industries." https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.216
31. U.S. Environmental Protection Agency. "Rubber Tire Manufacturing NESHAP (scope clarification)." https://www.epa.gov/stationary-sources-air-pollution/rubber-tire-manufacturing-national-emission-standards-hazardous
32. U.S. Bureau of Labor Statistics. "Table 1 — Incidence Rates of Nonfatal Occupational Injuries and Illnesses by Industry (NAICS 326291)." 2024. https://www.bls.gov/web/osh/table-1-industry-rates-national.htm
33. Trelleborg AB. "Trelleborg to Acquire Minnesota Rubber & Plastics (transaction announcement)." 2022. https://www.trelleborg.com/media/mfnnews/2022/trelleborg-to-acquire-minnesota-rubber-%2C-a-%2C-plastics
34. Trelleborg AB. "Trelleborg Confirms Key Financial Figures for Minnesota Rubber & Plastics." 2022. https://www.trelleborg.com/sv-se/media/mfnnews/2022/trelleborg-confirms-key-financial-figures-for-minnesota-rubber-%2C-a-%2C-plastics
35. Cabot Corporation. "Form 10-K for Fiscal Year 2025 (carbon-black feedstock description)." SEC Filing. https://www.sec.gov/Archives/edgar/data/16040/000119312525292412/cbt-20250930.htm