Styrene monomer
苯乙烯
Styrene monomer is the feedstock for polystyrene, ABS, SAN, and SBR rubber. Chinese capacity has more than doubled since 2020, with new world-scale complexes in Zhejiang and Liaoning bringing the country to net export. UN 2055, IMDG Class 3 Packing Group III flammable; ships in stainless T11 ISO tanks with the TBC (tert-butylcatechol) inhibitor at the spec rate (typically 10 to 50 ppm). Polymerisation risk in the tank is the dominant cargo-loss mode, and the inhibitor decay clock is real for any shipment older than 60 days from production. IARC Monograph 121 reclassified styrene as Group 2A (probably carcinogenic) in 2018. US imports do not carry Section 301 on bulk styrene at the time of writing. This cluster aggregates CAS 100-42-5 across the regulatory matrix and the CAS page.
Glossary
Terms you will meet on this lane
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Class 3, IMDG Class 3
The IMDG hazard class for flammable liquids, substances with a flash point of 60 degrees Celsius or below. Covers solvents, alcohols, ketones, esters, fuels, and many industrial intermediates routinely shipped from Chinese chemical factories. Subject to packing group I, II, or III based on flash point and initial boiling point.
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PG I / II / III, Packing Group
Three-tier classification under the IMDG Code (and other transport regulations) indicating the relative severity of hazard within a dangerous-goods class. PG I is the most hazardous (great danger), PG II is medium danger, PG III is minor danger. Determines the required packaging strength and the regulatory burden of the shipment.
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UN Number, UN Number
A four-digit identifier assigned by the United Nations Committee of Experts on the Transport of Dangerous Goods to identify a hazardous substance for international transport. Required on the DG Declaration, the package marking, the placards on the container, and Section 14 of the MSDS.
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DG Declaration, Dangerous Goods Declaration
A signed shipper's document required for every dangerous-goods sea shipment, certifying that the cargo has been properly classified, packaged, marked, labelled, and is in the proper condition for transport. Issued under the IMDG Code on the IMO Multimodal Dangerous Goods Form.
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ISO Tank, ISO Tank Container
A stainless-steel or alloy-steel cylindrical pressure vessel mounted in a 20-foot ISO container frame, designed for the transport of bulk liquids and gases. Capacities typically 18-26 cubic metres (16-25 MT depending on cargo density). UN portable tank instructions cover four families: T1 to T22 for liquids and solids of Classes 1 and 3 to 9, T23 for Class 4.1 self-reactive substances and Class 5.2 organic peroxides, T50 for non-refrigerated liquefied gases, and T75 for cryogenic liquefied gases. ISO tanks carry the bulk of the world's hazardous liquid chemical trade and compete with parcel tankers at different scales.
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SDS, Safety Data Sheet
The 16-section document that communicates the hazards, handling, storage, and emergency response information for a chemical product. Required at destination customs for any classified hazardous chemical and at the buyer's site for worker safety. SDS is the GHS-aligned successor to the older MSDS format.
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COA, Certificate of Analysis
A document issued by the manufacturer (or by an accredited third-party lab) certifying that a specific batch of a chemical or material meets the agreed specification. Lists tested parameters, results, the test methods used, and a batch number that ties back to production.
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FOB, Free On Board
Incoterm under which the seller delivers the goods on board the vessel at the named port of shipment. Risk and cost transfer to the buyer once the cargo crosses the ship's rail. The buyer arranges and pays for sea freight, marine insurance, and all destination-side costs.
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CIF, Cost, Insurance, and Freight
Incoterm under which the seller is responsible for the cost of the goods, marine insurance, and sea freight to the named destination port. Risk transfers from seller to buyer when the goods are loaded on board at the origin port, but cost responsibility extends to destination port arrival.
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HS Code, Harmonized System Code
A six-digit international product classification code used by customs authorities worldwide to identify goods, assess duties, and apply trade controls. Countries extend the six-digit base with additional digits for tariff and statistical purposes (10-digit HTS in the US, 8-digit CN code in the EU, 10-digit AHECC in Australia).
Regulatory matrix
Cross-jurisdiction compliance
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Styrene (vinylbenzene) under REACH
European Union listing status, classifications, importer obligations.
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Styrene (vinylbenzene) under TSCA
United States of America listing status, classifications, importer obligations.
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Styrene (vinylbenzene) under IECSC
People's Republic of China listing status, classifications, importer obligations.
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Styrene (vinylbenzene) under AICIS
Australia listing status, classifications, importer obligations.
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Styrene (vinylbenzene) under K-REACH
Republic of Korea listing status, classifications, importer obligations.
ISO tank types
Freight-form references for the cargo
Sourzi operator note
The TBC inhibitor figure on the COA is the loadbearing number for any styrene cargo that has been in the tank more than 30 days. Insist on the lab-confirmed value, not the spec-sheet number.
Curated by Sean. Primary-source verified per the regulatory drafting rules in Sourzi CLAUDE.md.
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