Other Warehousing and Storage (U.S.) — NAICS 493190

An investor's primer. Figures are reported facts with citations; statements about the future are labeled as judgments in the wording.

1. Overview

NAICS 493190 — "Other Warehousing and Storage" — is the catch-all bucket of the U.S. storage industry: businesses that get paid to hold someone else's goods when those goods are not general merchandise, not refrigerated, and not farm crops. NAICS stands for the North American Industry Classification System, the U.S. government's standard code for industries.[1] In practice the code covers three very different businesses under one label: bulk-liquid storage terminals (tank farms holding crude oil, gasoline, jet fuel, chemicals and, increasingly, biofuels), records and document storage (warehouses full of paper files and backup media), and a long tail of specialty operators — lumber terminals, bonded whiskey and wine warehouses, hazardous-materials storage, and automobile "dead" storage.[1]

Why it matters to an investor: storage is an infrastructure/annuity business. Owners collect recurring rent for space or volume, the assets (tanks, warehouses, land) last for decades, and once a facility is built the next barrel or box stored is highly profitable. The economics look more like toll roads and real estate than like manufacturing.

Two very different ways in. There is no large, pure-play publicly traded company for most of this industry. The closest listed pure play is Iron Mountain (records storage). Bulk-liquid terminals mostly sit inside diversified energy-midstream companies (Kinder Morgan, Energy Transfer/Sunoco, Global Partners) or are privately owned by infrastructure funds (IFM, Brookfield, Blackstone) and global operators (Vopak, Vitol, Oiltanking). So for many investors the real access is private-market, not the stock exchange — a point developed in Sections 4 and 10.

2. What it is, and what it excludes

In scope (493190): establishments primarily operating storage facilities except general merchandise, refrigerated, and farm-product storage. Storage must be the main service; ancillary services can include handling, labeling, inventory management, packaging, and arranging transportation. The Census Bureau's own illustrative examples are bulk petroleum storage, lumber storage terminals, document storage and warehousing, and whiskey warehousing. Index entries also include automobile dead storage and both public and private bonded warehousing (goods held under customs or tax bond).[1]

The defining feature is that the operator provides storage as a service and does not take ownership of the goods. That single distinction separates 493190 from several much larger adjacent industries — and it is why the federal statistics undercount the economic footprint of "storage" (Section 3). Activities classified elsewhere:[1]

• 531130 — Lessors of Miniwarehouses and Self-Storage Units. Consumer self-storage is treated as real estate, not warehousing. This matters for investors: the big listed self-storage names — Public Storage, Extra Space, CubeSmart — are not in 493190. That is a roughly $50-billion U.S. rental market sitting in a different code.[23]
• 424710 — Petroleum Bulk Stations and Terminals. If an operator takes title to the fuel and resells it (wholesaling), it is a wholesaler, not a storage provider. The same steel tank can land in 424710 or 493190 depending on whether the operator owns the product.[1]
• 493110 / 493120 / 493130 — general, refrigerated (cold storage), and farm-product warehousing, respectively. Contract-logistics and third-party-logistics (3PL) operators (GXO Logistics, Ryder), cold-storage giant Americold, and industrial landlords (Prologis) that get loosely called "warehousing" mostly live in these codes or in real estate — not here.[1]
• 562211 — hazardous-waste treatment/disposal storage; 486210 — natural-gas pipeline transportation and storage; 713930 — marinas (boat storage); 531190 — renting vacant lots for storage.[1]

Ownership mix. Overwhelmingly private and corporate. The supplied federal data do not give a public-versus-private split; concentration figures describe receipts by firm, not ownership by investor type. This is not a government-dominated industry and not one of individual hobby operators, but it does have a wide tail of small, closely held terminal and records companies underneath a handful of large owners.

3. How big it is (federal figures)

From our ground-truth federal statistics. These come from different programs and reference years, so treat them as a set of indicators, not one synchronized financial statement.

So by the official count this is a modest, service-heavy industry: roughly $9.4 billion of annual receipts, about 62,000 workers, and an average establishment of only ~23 employees. Payroll is close to half of receipts (though the two come from different years and programs), consistent with a labor-plus-real-estate service business rather than a capital-goods maker. The U.S. Small Business Administration (SBA) treats a firm here as "small" up to $36.5 million in receipts — an eligibility threshold, not an estimate of industry size — and most of the 1,439 firms fall well under it.[6] (Concentration among the largest firms is covered in Section 8. The Herfindahl-Hirschman Index, a standard concentration measure, is suppressed in the federal data and so is not reported here.)

The undercount caveat is important here. The $9.4-billion receipts figure badly understates how much "other storage" activity actually happens, for two reasons. First, the code captures only third-party storage-as-a-service, so it leaves out: (a) the enormous tonnage stored by companies that take title to the product and are counted as wholesalers (424710) or midstream energy firms; (b) storage done in-house by refiners, traders, and pipeline operators; and (c) consumer self-storage, parked in real estate (531130). Second, County Business Patterns and the Economic Census cover employer establishments and generally exclude government operations, so tiny nonemployer/owner-operated storage businesses are also missed.[2][5] There is no defensible adjustment for these gaps in the supplied file — but for scale, one industry research house pegs the U.S.-relevant bulk petroleum and chemical storage market alone in the tens of billions of dollars and growing toward ~$52 billion globally by 2030, dwarfing the census receipts for the pure-service code.[14] Read 493190's official numbers as the visible tip of a much larger storage economy.

4. The investable universe

There are very few clean public plays, and for most of the names below storage is only one segment of a bigger business. Because few public companies report 493190 as a standalone line, the listed universe is a proxy set. Scale figures are approximate market values in mid-2026, provided only to indicate size — tickers and prices belong to this section, not to the industry description above.

A structural note for investors. The three U.S. midstream names above (ET, SUN, GLP) are master limited partnerships (MLPs) — publicly traded partnerships that issue a Schedule K-1 tax form instead of a 1099 and pass income through to holders. That has real tax consequences and is a reason many index and retirement investors avoid them. Iron Mountain, by contrast, is a real estate investment trust (REIT) — a company that owns income real estate, pays little corporate tax, and must distribute most of its income as dividends.[8]

Major private / other owners dominate the bulk-liquid side: Buckeye Partners (taken private by IFM Investors in 2019), Zenith Energy, BWC Terminals, Vitol Tank Terminals, and Oiltanking (Marquard & Bahls) are all private.[14] On the records side, the large private number-two is Access (Access Information Management), a private-equity-backed roll-up that bought divested Recall assets when Iron Mountain acquired Recall in 2016, with Stericycle/Shred-it in adjacent document destruction.[10] The takeaway: if you want direct exposure to this industry, private markets are where most of the assets are.

5. How the money works

Owners in 493190 make money the same fundamental way — recurring rent for space or volume, plus fees for handling it — but the metrics differ by sub-segment. In shorthand: capacity × occupancy × storage rate + handling and value-added services.

The universal model:

• Storage rent (the annuity). Customers pay per unit of capacity over time — dollars per barrel per month (tanks), per square foot or cubic foot per month (warehouses), per carton per month (records). Stable, contracted, high-margin.
• Throughput / service fees (the variable layer). Terminals add fees for pumping product in and out, blending, heating, and additive injection; records firms charge for retrieval, transport, digitization, and secure destruction. Service revenue is more volume-sensitive than storage rent.
• The cost base is mostly fixed: land, tanks, buildings, racking and automation, security, insurance, maintenance, utilities/fuel, and environmental/customs/fire/safety compliance; labor is the largest variable line. Once a facility exists, incremental storage drops almost straight to profit, so utilization/occupancy is the swing variable. Investors watch tank utilization %, cubic-foot occupancy, or records volume, plus earnings before interest, taxes, depreciation and amortization (EBITDA) per unit of capacity, and — for landlord-style assets — net operating income (NOI). There is no 493190-specific occupancy, price, or margin series in the federal data; the Bureau of Labor Statistics (BLS) publishes broader warehousing wage data and a Producer Price Index (PPI) that serve only as loose proxies.[25]
• Contract structure. Terminals often sign multi-year take-or-pay deals (the customer pays for reserved capacity whether or not it uses it), which insulates cash flow from volume swings. Records contracts are effectively month-to-month but extremely sticky.

Segment specifics that drive the returns:

• Bulk-liquid terminals live and die on the shape of the commodity curve. When markets are in contango — future prices above today's spot price — traders profit by buying cheap product now, storing it, and selling forward, so storage demand and rental rates spike. The reverse (backwardation) empties tanks and pressures renewal rates. Storage is therefore a bet on oversupply and volatility, not on the oil price itself.[15][16]
• Records storage is almost the opposite: a low-growth, low-churn annuity. Boxes come in and rarely leave (permanent-removal rates are low), contracts carry annual price escalators, and industry estimates put Iron Mountain at roughly half of the organized physical-records market worldwide.[24] Key metrics are net box growth, revenue per box, and organic storage-rental growth. The cash flow is prized for its predictability — which is why the business is wrapped in a REIT and valued on adjusted funds from operations (AFFO), a REIT cash-flow measure.[8]
• Specialty (whiskey, lumber, hazmat) earns multi-year, often bond-related storage fees. Bourbon and whiskey age for years in bonded warehouses where excise tax is deferred until withdrawal, so the aging boom has driven barrel-storage demand.

Capital intensity and moats. Tanks, waterfront/rail/pipeline access, permits, and environmental liabilities make new supply slow and expensive to build — a genuine barrier to entry that protects incumbents' pricing. The land and steel also carry real balance-sheet value.

6. What drives demand

• Commodity price structure and volatility. Contango, glut, and trading activity fill tanks; energy-security stockpiling adds a floor. Global commercial oil storage rose to about 1.07 billion barrels by late 2025, and governments have been expanding strategic reserves — a demand tailwind for terminals.[17][15]
• Trade flows and inventories. Imports/exports, port throughput, tariffs, reshoring, and companies' inventory-to-sales ratios drive demand for general and overflow storage. Much of that activity sits in adjacent codes (general/refrigerated warehousing), but it sets the tone for the whole storage sector.
• Regulatory retention requirements underpin records storage: tax rules, litigation holds, and laws like HIPAA (the Health Insurance Portability and Accountability Act, governing medical records) and the Sarbanes–Oxley Act (SOX, governing corporate records) force companies to keep documents for years, even as paper slowly declines.
• Energy-mix shifts. Rising biofuels, renewable diesel, and ammonia blending is creating fresh demand for specialized tankage even where traditional petroleum demand plateaus (a forward-looking driver, not yet a settled fact).[14]
• Specialty booms — aging spirits, building-materials/lumber cycles, and chemicals — move their respective niches.

7. Regulation

Storage is not price-regulated like a utility — fees are market-set. Instead the binding rules are environmental, safety, security, and customs/tax:

• EPA Spill Prevention, Control, and Countermeasure (SPCC) rule (40 CFR 112): facilities above an aggregate aboveground threshold — generally 1,320 gallons of oil storage — must have secondary containment (dikes/berms), inspection schedules, and an engineer-certified spill plan. EPA is the U.S. Environmental Protection Agency.[18]
• API 653 tank inspection and repair standard governs the in-service integrity of large field-erected steel tanks; API is the American Petroleum Institute.[19]
• OSHA standards cover worker and fire safety — powered-industrial-truck (forklift) rules at 29 CFR 1910.178 and flammable-liquid handling at 29 CFR 1910.106. OSHA is the Occupational Safety and Health Administration.[20]
• Coast Guard / MTSA facility-security requirements apply to waterfront terminals (MTSA = Maritime Transportation Security Act); the Resource Conservation and Recovery Act (RCRA) governs hazardous materials; the Clean Water Act and local fire codes also bite.
• Bonded warehousing is overseen by U.S. Customs and Border Protection (CBP), which permits imported dutiable goods to be held without immediate duty payment for up to five years; foreign-trade zones (FTZs) are a related customs mechanism for secure storage and processing.[21] For spirits, the Alcohol and Tobacco Tax and Trade Bureau (TTB) defers excise tax on aging whiskey and requires permits, inventory controls, and periodic storage reports.[22]
• Records storage faces data-privacy and chain-of-custody obligations more than heavy operational regulation.

The through-line: compliance is a cost and a liability, but it is also a moat — it deters casual new entrants.

8. Competitive dynamics and consolidation

The federal concentration data show a top-heavy but long-tailed industry: the four largest firms take 42.9% of receipts, the top eight 53.7%, the top twenty 66.7%, and the top fifty 78.8% — leaving hundreds of small operators to split the rest.[4] Meaningfully concentrated, but not dominated by a mere handful. (The HHI is suppressed in the source, so no HHI value should be inferred.)

The strongest competitive positions usually combine access to ports, rail, pipelines or major customers; specialized buildings, tanks, security, or handling equipment; reliable inventory controls and chain-of-custody procedures; regulatory expertise; and long customer relationships with low switching incentives.

Consolidation has been the dominant theme in both halves of the business:

• Records: Iron Mountain's 2016 acquisition of Recall (the former number two) was cleared only after antitrust-forced divestitures — many of which went to Access, seeding today's private number two.[10] Iron Mountain has since leaned into data centers and digitization to offset slow paper decline.[9]
• Bulk-liquid terminals: a wave of deals has thinned the field — Buckeye Partners taken private by IFM (2019), Magellan Midstream absorbed by ONEOK (2023), and NuStar Energy absorbed by Sunoco/Energy Transfer (2024).[12] Kinder Morgan remains the largest independent U.S. terminal operator.[11] Infrastructure funds (IFM, Brookfield, Blackstone, ArcLight) have been the most aggressive buyers, treating terminals as long-duration, inflation-linked assets.

High barriers — permits, waterfront/rail access, tank capital, and environmental liability — mean incumbents rarely face greenfield competition; the fight is over acquisitions and contract renewals. Judgment: consolidation is most compelling in records, compliance-heavy niches, and scarce-location terminals; generic, commodity-sensitive storage space is more exposed to local oversupply and price competition.

9. Risks

• Commodity-cycle whiplash. Terminal demand and rental rates swing with contango/backwardation. A prolonged backwardated or low-volatility market empties tanks and pressures renewals.[16]
• Energy transition (long-term). Structural decline in petroleum-product demand could eventually reduce the need for fuel storage. A forward-looking risk, partly offset by repurposing tanks for biofuels, renewable diesel, and ammonia.
• Secular decline of paper. Physical records volumes grow slowly and could shrink; the offset is stickiness, escalators, and the pivot to digitization and data centers.
• Environmental and safety liability. Spills, soil/groundwater contamination, tank failures, fires, and emerging rules on PFAS ("forever chemicals," per- and polyfluoroalkyl substances, used in firefighting foam) can create large remediation and insurance costs.
• Interest-rate and valuation sensitivity. As real-estate-like assets (a REIT, MLPs, infrastructure funds), storage valuations move with interest rates and capitalization rates.
• Customer and contract concentration. Terminals can depend on a few large shippers; non-renewal is a real cash-flow risk.
• Labor. The warehouse/records side is operationally intensive; wage increases, turnover, and staffing shortages can compress margins.
• Tax-structure friction. MLP K-1s and REIT distribution rules narrow the buyer base and complicate ownership.
• Disclosure and classification risk. Public companies bury 493190 exposure inside larger businesses, and private operators disclose little — while a company described as a "warehouse" may primarily be in general warehousing, cold storage, self-storage, real estate, transportation, or wholesale trade. Read the segment detail before assuming exposure.

10. How to invest, and the outlook

Public routes (separate three kinds of exposure):

• Storage as the core business: Iron Mountain (IRM) is the only large listed way to own it — a REIT with a records annuity and a fast-growing data-center arm, held largely for its dividend and recurring cash flow.[7][8]
• Diversified midstream with big terminal footprints: Kinder Morgan (KMI), Energy Transfer (ET) and its Sunoco (SUN) unit, and Global Partners (GLP) give indirect exposure; storage is a slice, and the MLPs carry K-1 tax treatment.[11][12][13]
• Foreign-listed pure play: Royal Vopak (VPK, Amsterdam) is the purest listed bulk-liquid storage play, but requires access to a European exchange.

Private routes are where most of the assets actually sit: infrastructure funds (IFM, Brookfield, Blackstone, ArcLight) that own terminal networks; private-equity-backed records firms such as Access; sale-leasebacks, specialty-terminal development, private credit, and direct ownership of terminal/warehouse real estate. Niche vehicles for aging-whiskey barrels exist but are speculative and illiquid.

Near-term drivers (forward-looking judgments). Storage demand looks supported by energy-security stockpiling, trade and price volatility, and biofuels blending, all of which favor terminal utilization.[15][17] Records storage should remain a stable annuity in slow secular decline, cushioned by escalators and the data-center pivot. Consolidation is likely to continue, with infrastructure capital the marginal buyer. The main long-term swing factor is the energy transition — a headwind for petroleum tankage that could be partly reclaimed by repurposing assets for lower-carbon fuels.

For a general investor, the practical read is that 493190 is an infrastructure-style, income-oriented corner of the market — steadier than most industrials, but one you mostly reach through a REIT, a handful of midstream MLPs, or private funds rather than a single clean stock. The central underwriting question is not "how much space does the company control?" but: how much occupied, specialized, contract-backed capacity can it operate at an attractive margin after labor, rent, energy, compliance, and maintenance costs?

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Sources

1. U.S. Census Bureau, "North American Industry Classification System: 493190 Other Warehousing and Storage" (2022 definition, illustrative examples, and cross-references). https://www.census.gov/naics/?input=493190&year=2022&details=493190
2. U.S. Census Bureau, County Business Patterns: 2023 (establishments, employment, annual and first-quarter payroll for NAICS 493190). https://www.census.gov/programs-surveys/cbp.html
3. U.S. Census Bureau, 2022 Economic Census, Summary Statistics (receipts and firm counts for NAICS 493190). https://www.census.gov/programs-surveys/economic-census.html
4. U.S. Census Bureau, "Concentration of Largest Firms: 2022" Economic Census (CR4 42.9%, CR8 53.7%, CR20 66.7%, CR50 78.8%; HHI suppressed). https://data.census.gov/table/ECNSIZE2022.EC2200SIZECONCEN
5. U.S. Census Bureau, 2022 Economic Census Methodology (coverage of employer establishments; exclusions). https://www.census.gov/programs-surveys/economic-census/year/2022/technical-documentation/methodology.html
6. U.S. Small Business Administration, "Table of Size Standards" (NAICS 493190 = $36.5 million), 2023. https://www.sba.gov/document/support-table-size-standards
7. Iron Mountain Incorporated, "Iron Mountain Reports Fourth Quarter and Full Year 2024 Results" (~$6.1B revenue; storage rental +8%, service +17%), 2025. https://www.businesswire.com/news/home/20250213929445/en/Iron-Mountain-Reports-Fourth-Quarter-and-Full-Year-2024-Results
8. U.S. Securities and Exchange Commission, Iron Mountain Form 10-K (REIT structure; segment mix; ~85% records & information management). https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001020569&type=10-K
9. DataCenterDynamics, "Q4 2024 data center colocation results: Digital Realty, Equinix, and Iron Mountain" (Iron Mountain data-center revenue ~$620M, +25%), 2025. https://www.datacenterdynamics.com/en/news/q4-2024-data-center-colocation-results-digital-realty-equinix-and-iron-mountain/
10. U.S. Department of Justice, "Iron Mountain and Recall Holdings Agree to Divest Records Management Assets," 2016. https://www.justice.gov/archives/opa/pr/iron-mountain-and-recall-holdings-agree-divest-records-management-assets-condition-proceed
11. Kinder Morgan, "Terminals" (largest independent U.S. terminal operator; ~136 terminals; ~141 million barrels liquids capacity). https://www.kindermorgan.com/Operations/Terminals/Index
12. PR Newswire, "Sunoco LP to Acquire NuStar Energy L.P. in Transaction Valued at $7.3 Billion" (~63 terminals), 2024. https://www.prnewswire.com/news-releases/sunoco-lp-to-acquire-nustar-energy-lp-in-transaction-valued-at-7-3-billion-302040392.html
13. StockTitan, "Global Partners LP overview" (~55 liquid-energy terminals; ~21 million barrels), and coverage of the Gulf Oil terminals acquisition, 2024. https://www.stocktitan.net/overview/GLP/
14. GlobeNewswire, "Bulk Petroleum and Chemical Storage Industry Report 2026–2035: A $51.92 Billion Market by 2030," 2026. https://www.globenewswire.com/news-release/2026/02/26/3245861/28124/en/Bulk-Petroleum-and-Chemical-Storage-Industry-Report-2026-2035-A-51-92-Billion-Market-by-2030.html
15. S&P Global Commodity Insights, "Commodities 2026: Oil storage expands globally as energy security, trading drive demand," 2026. https://www.spglobal.com/commodityinsights/en/market-insights/latest-news/crude-oil/010826-commodities-2026-oil-storage-expands
16. Center for Strategic and International Studies (CSIS), "Filled to the Brim: The Importance of Flexible and Innovative Storage in Commodities Markets." https://www.csis.org/analysis/filled-brim-importance-flexible-and-innovative-storage-commodities-markets
17. GlobeNewswire / Astute Analytica, "Oil Storage Market to Worth Over US$16.7 Billion by 2033" (global commercial oil storage ~1.07 billion barrels by late 2025), 2025. https://www.globenewswire.com/news-release/2025/11/10/3184911/0/en/Oil-Storage-Market-to-Worth-Over-US-16-7-Billion-by-2033-Astute-Analytica.html
18. U.S. Environmental Protection Agency, "Spill Prevention, Control, and Countermeasure (SPCC)" / aboveground storage tanks (40 CFR 112; 1,320-gallon threshold). https://www.epa.gov/oil-spills-prevention-and-preparedness-regulations/overview-spill-prevention-control-and
19. iFluids Engineering, "API 653 Tank Inspection Code — In-Service Integrity Explained" (American Petroleum Institute standard). https://ifluids.com/standard/api-653-tank-inspection-code/
20. Occupational Safety and Health Administration, "Warehousing" (powered industrial trucks, 29 CFR 1910.178) and flammable liquids (29 CFR 1910.106). https://www.osha.gov/warehousing
21. U.S. Customs and Border Protection, "What Is a Customs Bonded Warehouse?" (up to five-year storage) and Foreign-Trade Zones FAQ. https://www.help.cbp.gov/s/article/Article1853?language=en_US
22. Alcohol and Tobacco Tax and Trade Bureau, storage/permitting for distilled spirits (Form 5110.11 storage report). https://www.ttb.gov/ttb-form-511011
23. U.S. Census Bureau / NAICS Association, "531130 — Lessors of Miniwarehouses and Self-Storage Units" (self-storage classified as real estate; ~$50B U.S. market). https://www.naics.com/naics-code-description/?code=531130
24. Statista, "Iron Mountain revenue by segment" (~85% records & information management); industry estimates of ~50% share of the organized physical-records market worldwide. https://www.statista.com/statistics/1464030/iron-mountain-revenue-by-segment/
25. U.S. Bureau of Labor Statistics, Warehousing and Storage industry data and Producer Price Index (broad proxies; not specific to 493190). https://www.bls.gov/iag/tgs/iag493.htm; https://www.bls.gov/ppi/overview.htm
26. Market capitalizations (mid-2026, approximate): companiesmarketcap.com (IRM, KMI), stockanalysis.com (SUN, GLP), tradingeconomics.com (Vopak). https://companiesmarketcap.com/iron-mountain/marketcap/; https://companiesmarketcap.com/kinder-morgan/marketcap/; https://stockanalysis.com/stocks/sun/market-cap/; https://stockanalysis.com/stocks/glp/market-cap/; https://tradingeconomics.com/vpk:na:market-capitalization