Epichlorohydrin (ECH) Supply: Grades, Specs, UN 2023 Logistics and Instant Quote

Epichlorohydrin (ECH, CAS 106-89-8; molar mass 92.52 g/mol) is a chlorinated epoxide monomer supplied as a low-viscosity liquid with a closed-cup flash point of 31°C and a normal boiling point range of 115–117°C. The material is classified as UN 2023, Class 6.1, Packing Group II, with a subsidiary Class 3 flammability hazard. Industrial supply is organized around epoxy-grade and technical-grade specifications because moisture, acidity, and trace metal contamination directly affect downstream reaction selectivity and resin colour.

Global ECH supply is driven by propylene-chlorine capacity rather than by downstream resin demand alone. The standard production route proceeds from propylene to allyl chloride, followed by hypochlorous acid addition to form dichloropropanols and dehydrochlorination with caustic. Plants may use either chlorohydrin or glycerol-to-epichlorohydrin routes; the latter consumes glycerine as a chlorine sink and can shift the impurity profile. Supply contracts therefore specify not only ECH purity but also upstream allyl chloride and 1,3-dichloropropanol residues, because these compounds can act as crosslink scavengers or odour sources in downstream wet-strength resins.

What Distinguishes Epoxy-Grade from Technical-Grade ECH?

Commercial ECH is segregated into at least two supply classes: epoxy-grade material for controlled oligomer synthesis and technical-grade material for broader industrial derivatization. The difference is not always visible at receiving; it is controlled through the certificate of analysis and the upstream drying train. Epoxy-grade material is typically delivered with a water content of ≤100 mg/kg because water hydrolyzes the oxirane ring to 3-chloro-1,2-propanediol, which acts as a chain transfer agent in liquid epoxy resin advancement. Technical-grade material may be accepted at ≤200 mg/kg for synthetic glycerol, where downstream hydrolysis tolerates a higher water load but not an elevated acidity.

Total chlorinated impurities are usually reported as 1,3-dichloropropanol and allyl chloride. Epoxy-grade material is often controlled below 500 mg/kg for total chlorinated species excluding ECH, while technical-grade may be supplied up to 1500 mg/kg. These values are not fixed by a single international standard; they vary between producers and export routes. Any comparison between suppliers should use the same gas chromatographic column and integration settings because co-eluting chlorinated propanes can shift the apparent assay by several tenths of a percent.

Parameter	Epoxy-grade typical band	Technical-grade typical band	Test method
ECH assay, area percent	99.9 min	99.0 min	GC-FID normalised
Colour, Pt-Co	10 max	20 max	ASTM D1209
Water	100 mg/kg max	200 mg/kg max	ISO 760
Density at 20°C	1.180–1.184 g/cm³	1.178–1.185 g/cm³	ISO 12185 / ASTM D4052
Acidity as HCl	10 mg/kg max	20 mg/kg max	ASTM D1613
Iron	0.5 mg/kg max	1.0 mg/kg max	ICP-OES

These bands are representative of commonly observed certificates of analysis, not a single global standard. Purchasers should align each shipment against the supplier’s CoA and the applicable REACH or local inventory registration because some downstream food-contact resin applications require lower residual chlorinated impurities than the technical-grade band.

In continuous epoxy resin trains using wiped-film evaporators, moisture above the specified ceiling increases the load on the final vacuum stripping section. ECH water entering the bisphenol A condensation reactor generates chlorohydrins that persist as hydrolyzable chloride in the finished resin. For a standard liquid epoxy resin with a target epoxy equivalent weight of 182–192 g/eq, some producers control total hydrolyzable chloride to below 500 mg/kg in the resin, which requires ECH water and acidity to be held within the epoxy-grade band. Published data for the exact effect of trace iron on resin colour is limited, but iron contamination above 0.5 mg/kg is associated with browning in downstream diaminodiphenyl sulfone-cured systems.

The theoretical oxirane oxygen content of pure ECH is 17.3% by mass. This value is not routinely used as a release specification because gas chromatographic assay is more reproducible in the presence of moisture and chlorinated impurities. Some downstream epoxy resin technical data sheets instead report the epoxy equivalent weight of the prepared DGEBA resin, normally in the range of 182–192 g/eq, which is indirectly sensitive to ECH charge purity and water ingress.

In epichlorohydrin elastomer manufacture, ECH is copolymerised with ethylene oxide or propylene oxide using organometallic catalysts. The resulting polyether backbone gives the elastomer low gas permeability and oil resistance; the chlorine side groups function as cure sites for triazine-based vulcanisation. ECH purity and water content affect catalyst consumption because active organometallic initiators are deactivated by hydroxyl and acid impurities. A technical-grade stream with water above 200 mg/kg can reduce polymerisation yield and shift the Mooney viscosity of the finished elastomer.

Wet-strength paper resins based on polyamidoamine-epichlorohydrin consume technical-grade ECH in an aqueous reaction system where the monomer is added at controlled pH and temperature. Excess water is present by design, so the moisture specification is less critical than the acidity and iron classes. However, residual 1,3-dichloropropanol in the ECH feed can persist into the final paper chemical as a by-product; industrial customers often specify a maximum level on the ECH certificate of analysis to maintain compliance with national food-contact regulations.

Synthetic glycerol production via ECH hydrolysis typically accepts technical-grade material with a higher water ceiling because the feed is immediately contacted with aqueous alkali. In this route, the energetic hazard is not moisture ingress but uncontrolled base addition; ECH reacts exothermically with sodium hydroxide to form glycidol and glycerol, and the reactor temperature must be held below 60°C until the epoxide has been consumed. Supply of ECH to glycerol trains is often scheduled in dedicated tank containers because residual caustic in return tanks can cause runaway polymerisation of the next load.

When the Receiving Tank Is Opened at Relative Humidity Above 60%

Unloading of ISO tank containers or drums under ambient relative humidity above 60% requires dry air or nitrogen padding of the headspace. At production-scale resin plants, moisture ingress during open sampling is a repeatable cause of water excursions that trip the feed dryer inlet alarm. Receiving vessels should be equipped with pressure/vacuum relief set at -2 kPa to +5 kPa gauge and a desiccated vent filter. Transfer lines are typically stainless steel 316L with electro-polished welds to reduce iron pickup; flexible hoses are specified with PTFE-laminated stainless steel braid because ECH attacks nitrile and natural rubber gaskets through swelling and embrittlement.

Storage vessels should be blanketed with nitrogen at a positive pressure of 0.5–1.5 kPa gauge to exclude atmospheric moisture and oxygen. ECH is stable for at least 12 months in closed stainless steel 316L or lined carbon steel tanks when temperature is maintained below 40°C and contact with acids, bases, metal halides, or free water is prevented. The material is not a peroxide former in normal closed storage, but it can undergo slow hydrolysis and acid-catalysed homopolymerisation if the headspace dew point is not controlled. Equipment layouts should segregate ECH storage from oxidising agents, sodium hydroxide, and amines.

Marine transport of ECH falls under the International Maritime Dangerous Goods Code as UN 2023, Class 6.1, Packing Group II, with a subsidiary Class 3 flammability hazard. The assigned proper shipping name is Epichlorohydrin. Closed-cup flash point is 31°C; the liquid is therefore classified as flammable in transport, but the primary class remains toxic. For road and rail within ADR/RID member states, the same UN number and packing group apply; tanks and packages must display Class 6.1 labels and Class 3 subsidiary labels. Segregation from oxidising agents and strong acids is required at all points in the supply chain.

UN 2023 Logistics Data and Packaging Boundaries

The UN 2023 classification governs every mode of movement: road, rail, short-sea, and deep-sea. The primary hazard is toxic by inhalation and skin contact; the subsidiary flammability hazard is due to the 31°C closed-cup flash point. Packing Group II indicates high danger for transport and requires more restrictive package selection than lower packing groups. For intermodal tank containers, the ECH service fleet is generally stainless steel 316L with top discharge, pressure/vacuum relief, and gaskets of expanded PTFE. Drummed shipments are commonly 200 L steel drums with epoxy-phenolic linings, loaded to approximately 200 kg net mass per drum; intermediate bulk containers are used only where the logistics provider has verified compatibility and regulatory thresholds.

Transport parameter	Typical value or code	Notes
UN number	2023	Posted on tank container and drums
Proper shipping name	Epichlorohydrin	IMDG Code / ADR
Primary hazard class	6.1 toxic liquids	Class 6.1 label
Subsidiary hazard class	3 flammable liquid	Subsidiary 3 label
Packing group	II	High danger; restricted packages
Flash point, closed cup	31°C	Flammable but primary toxic
Boiling point range	115–117°C	At 101.3 kPa
Density at 20°C	1.18 g/cm³	Tank capacity and ullage calculation
Vapour pressure at 20°C	approx. 1.7 kPa	Tight-fill and vent design

Segregation must be verified against the IMDG segregation table and the ADR dangerous goods list. ECH must be separated from oxidising agents, strong acids, alkalis, and metal halide catalysts. For rail transport under RID, ECH in tank wagons must use a tank code appropriate for a toxic flammable liquid; published tank code assignments should be verified against the current RID Part 2 dangerous goods list. Vapour return lines are closed during unloading, and the receiving tank must be equipped with a level transmitter independent of the loading gauge to prevent overfill beyond 85% volumetric fill at 20°C.

Port storage and transshipment for UN 2023 are governed by IMDG Code segregation and by the terminal’s dangerous goods class separation matrix. Container yards generally place UN 2023 away from Class 5.1 oxidizers and Class 8 corrosive acids, and some terminals require pad containment under the tank for leakage collection. Where ECH is not listed as a severe marine pollutant under MARPOL Annex III, wash water is still controlled under national permit limits because of the mixture toxicity of ECH to aquatic organisms.

Pressure/Vacuum Relief Settings Are Derived from Vapour Pressure and Flash Point

At a receiving terminal, pressure/vacuum relief valves are set to manage vapour generated by the 31°C flash point and the approximately 1.7 kPa vapour pressure at 20°C. The valves are not selected only for fire engulfment; they also protect against pressure swings during top-discharge nitrogen padding and during cooling after daytime tank warm-up. A relief set point of 4.0 bar is typical for some ISO tank containers, though the exact setting must be confirmed on the tank certificate. Venting from a Class 6.1 toxic with a subsidiary Class 3 flammability hazard must be routed to a closed scrubber or activated carbon bed where local permit conditions require emission control.

Tank cleaning after discharge is another critical logistics constraint. Return tanks are washed with hot demineralised water and steam, then dried and nitrogen-purged until the dew point is below -40°C. Any residual ECH left in a tank heel reacts with water, forming chlorohydrin and hydrochloric acid, which can pit 316L stainless steel at the tank bottom. Batches of return tanks arriving without a clean, dry certificate are quarantined until a 0.1% by volume residual can be excluded by gas detector or laboratory analysis.

The instant quote module processes ECH supply requests by validating grade, net mass, packaging, route, and documentation before returning a provisional price. Required inputs include the requested assay band, target moisture, delivery port, final destination, mode, and the preferred Incoterms 2020 rule. Because UN 2023 shipments must comply with carrier restrictions, the system rejects configurations where the packaging is incompatible with Packing Group II or where segregation cannot be confirmed. A provisional quote is generated only after the requesting party uploads a valid safety data sheet revision date, the applicable REACH or UK-REACH registration number, and the target delivery schedule. For bulk ISO tank supply, the quote includes a tank demurrage and cleaning line item because return tanks must meet the dew-point and residual-free condition described above.

The instant quote result does not replace a formal sales contract; it provides a binding-in-scope price only after laboratory-grade specification confirmation and a clean bill of lading are issued. For drummed lots, the quotation returns an EXW or FOB line item based on factory filling slot availability; for ISO tank lots, the quote returns a CFR or CIF port-to-port line item with named origin and destination terminals. ECH supply grades are allocated by batch number, and the final certificate of analysis is linked to the transport emergency card for UN 2023. The instant quote engine also validates UN 2023 labels and packing group against the booking class. Carriers may reject a load if the shipper declaration lists Class 3 as primary instead of Class 6.1. This check reduces the risk that a freight forwarder books the material under a flammable liquid rate code, which would under-declare the toxic hazard and create a dangerous goods incident.