Epichlorohydrin (ECH; CAS 106-89-8) is a chlorinated oxirane intermediate with a molar mass of 92.52 g/mol, a flash point near 31 °C, and a transport classification under UN 2023. Its largest downstream route is the formation of bisphenol A diglycidyl ether for liquid epoxy resins, followed by epichlorohydrin elastomers, polyamide wet-strength resins, and quaternary ammonium water-treatment polymers. Because ECH contains both a strained epoxide ring and a chloromethyl group, its order-to-delivery sequence is governed less by shipping distance and more by moisture exclusion, previous-cargo compatibility, and documentation alignment under CLP Regulation (EC) No 1272/2008.

Bulk isotank and road tanker movements require more control than drum or intermediate bulk container shipments. A receiving site that stores ECH in a wet or amine-contaminated tank can initiate premature oligomerization, colour drift, or off-spec water content before the material reaches the reactor. The sequence below identifies ten distinct control points from initial inquiry to receiver offloading.

Epichlorohydrin Order-to-Delivery Process: A Transparent 10-Step Timeline

1. Inquiry and specification alignment. The purchaser supplies a technical specification covering epichlorohydrin purity, water content, APHA colour, acidity, and residual chlorinated impurities. GC-FID area percent is used for main-component purity; water is determined by Karl Fischer coulometry according to ISO 760. A bulk supply agreement normally fixes water below a supplier-specific threshold, frequently documented in the range of 0.01–0.05 mass%. The specification may also distinguish between epoxy resin grade and epichlorohydrin rubber grade, because the latter is more sensitive to oxygenated ring-opened impurities that act as chain stoppers or alter sulphur curing kinetics. Transport mode is locked at this stage: 240 L drums, 1,000 L IBCs, or bulk isotainers with payloads near 24,000–25,000 kg. Bulk movements trigger the tank qualification steps that small-pack shipments do not.

The term “purity” is not always method-neutral. A supplier’s GC-FID area percent may not fully resolve high-boiling oxygenates if the injection port temperature is too low or the column is non-polar. Purchase specifications therefore benefit from an agreed referee method and a retained sample protocol before the first bulk order is placed.

2. Order entry and dangerous-goods profile check. The supplier’s ERP material master blocks order entry unless the ship-to party has a valid dangerous-goods receiving permit, the transport classification is confirmed as UN 2023, Class 6.1, packing group II, and the safety data sheet has been supplied. Purchase order confirmation includes Incoterms, delivery window, and batch quantity. This step is administratively shallow but prevents downstream border rejection.

When a bulk isotainer order triggers tank qualification controls

3. Tank preparation and previous-cargo review. The tank container or road tanker cannot be scheduled until the last three cargoes are evaluated. Acceptable previous cargoes are typically dry chlorinated or oxygenated solvents that do not leave free water or a reactive heel. Tanks with previous amine, caustic, or water-based cargoes are either rejected or subjected to wash, dry, and wall-drying verification. The tank is purged with nitrogen until the oxygen concentration is below the loading terminal’s maximum, commonly 5 vol% or lower for flammable-liquid service. A clean-tank certificate is issued after visual inspection and drain sampling. The time between certificate issue and loading is limited by the terminal’s procedure, often to 72 h or less, because a sealed clean tank can still accumulate moisture through manlid seal leakage.

Field experience on bulk loading racks shows that residual tank heel water is a more common release failure than pump or meter error. A 10 L free-water heel in a 24,000 kg ECH tank can contribute approximately 0.04 mass% water, enough to consume most of a tight moisture allowance before the product reaches the customer. Loading hoses and gaskets are inspected for black ethylene-propylene residues; only product-compatible gasket materials specified by the loading procedure are permitted. Electrical equipment and vents are classified according to EN 60079-10-1 hazardous area zones, and flame arrestors are maintained to EN ISO 16852 where detonation arrestors are required. Connection is interlocked with the earthing clamp and the pump start circuit.

4. Batch allocation and certificate-of-analysis alignment. The planning function matches the order against an in-process batch or an upcoming campaign. If the requested water limit is tighter than the standard commercial specification, the batch is selected only if the last three batch results show sufficient statistical process control margin. Under ISO 9001:2015 clause 8.4, the tank-cleaning subcontractor and analytical laboratory are included in the supplier’s external provider control programme. The system assigns a unique lot number and links the order to the future certificate of analysis. Once the lot is assigned, any change in the ship-to site triggers a new regulatory check.

5. Production and in-process control. Commercial ECH is produced by either the classical allyl chloride hypochlorination route or the glycerol-to-ECH route. In the glycerol route, glycerol is hydrochlorinated to dichloropropanols, followed by caustic dehydrochlorination with sodium hydroxide. The saponifier is operated with strict pH and temperature control because the epoxide ring is sensitive to alkaline hydrolysis; local excursions generate glycidol and monochloropropanediol, which reduce yield and alter odour and colour. Process automation monitors the fractional distillation column reflux ratio, feed preheat temperature, and reboiler steam flow. The distillation section is maintained below atmospheric pressure to limit reboiler temperature and suppress thermal ring-opening.

In-process sampling points are located at the crude fractionator overhead, the purified product cooler, and the final product tank. GC-FID trending covers low-boiling chlorinated compounds and high-boiling oxygenates. Density is measured by ASTM D4052 at 20 °C; a specific gravity outside the typical range of 1.177–1.183 triggers a re-sample and column profile check. The product tank is dried and nitrogen-padded. If the APHA colour exceeds the control limit, the tank is isolated for re-distillation or downgrade review.

6. Laboratory release and certificate of analysis. Final release requires a matched customer specification and supplier release limit. The table below lists the principal commercial release boundaries used in bulk ECH supply; individual suppliers may tighten or widen these values through their technical data sheets.

For liquid epoxy resin producers, the critical limit is often tighter than the standard commercial sheet. The final epoxy resin hydrolyzable chloride specification is influenced by the ECH water and chlorinated impurity profile, so a bulk ECH lot may be accepted for one application and rejected for another even when all standard commercial values are met. Batch-to-batch variance is monitored with control charts. A batch that meets the commercial limit may still be non-conforming for a purchaser using a rapid densitometric check if the local method is not aligned to the supplier’s GC-FID calibration. Disputes are resolved by retaining the loaded reference sample and cross-testing under an agreed referee method. Published data for method-dependent ECH water measurement at levels below 0.02 mass% indicate that Karl Fischer conditioning and sampling moisture ingress can introduce more error than the instrument repeatability.

7. Bulk loading and inerting. Loading is executed only after the clean-tank certificate and batch release are aligned. The tank truck or isotank is positioned, bonded to the loading gantry, and connected to the vapour balance system. Nitrogen padding is maintained in the vapour space; air-based drying is not used because it can reintroduce moisture. The loading pump is a sealless canned motor or magnetically driven unit selected to reduce shaft-seal emissions. Initial flow is held at a reduced rate until the downcomer is submerged to avoid static charge accumulation; the maximum loading rate is based on API RP 2003 electrostatic criteria. Vapour displaced from the tank is returned to a scrubber or flare knock-out vessel. Open venting is not permitted under site permits and REACH exposure-control obligations.

The vapour balance system is designed so that displaced gas does not dead-end into a closed vent header; pressure in the receiving scrubber is monitored to avoid backpressure on the tank relief device. Hose assemblies are pressure-tested according to the site’s written scheme, and gasket material is validated by the supplier’s compatibility data. After loading, the compartment is sealed and positive nitrogen pressure is verified. A retained sample is drawn from the loaded tank or compartment, labelled with the order number, and stored for the required retention period. The loading ticket records the actual loaded mass, tank number, seal number, start and finish times, and the operator’s confirmation of earthing continuity.

Shipping documentation and regulatory boundary checks

8. Documentation validation. The shipping set includes the dangerous-goods declaration, the packing certificate, the certificate of analysis, the tank clean certificate, and the loading ticket. The dangerous-goods description must use the proper shipping name “Epichlorohydrin,” UN 2023, Class 6.1, packing group II. Under ADR, the tunnel restriction code and the hazard identification number must match the main hazard and subsidiary risk. Under IATA DGR, bulk ECH would not move by air; drums are limited by the relevant instruction and operator variation. Under IMDG, the marine pollutant status is declared if applicable. Discrepancies in SDS section 14 or the transport emergency card are treated as stop-shipment events until corrected.

A shipper may not issue a simplified transport document for bulk ECH under the small load exemption thresholds in ADR 1.1.3.6 when the transported quantity exceeds the calculated transport category threshold. Misapplication of these thresholds is a recurring nonconformity in multi-drop loads. Receiving sites in the European Union must have the safety data sheet compliant with Annex II of Regulation (EC) No 1272/2008 before delivery. The SDS must state the harmonised classification for skin corrosion, acute toxicity, and flammability. A site receiving under a REACH authorisation or restriction scenario is not cleared simply by the transport document; the use descriptor and end-use confirmation may be required at order entry.

9. In-transit monitoring. Bulk road tanker and isotank movements are monitored for location, tank pressure, and unplanned route deviations. Since ECH flash point is near 31 °C, solar exposure in high-ambient regions can raise the tank skin temperature above ambient but does not normally require active refrigeration. Pressure telemetry detects leaks, thermal expansion, or pad-gas loss. Drum and IBC shipments are packed with absorbent spill kits, but real-time telemetry is generally not cost-effective for these smaller units. Published data for real-time temperature telemetry specific to ECH road tanker fleets is limited; operational monitoring tends to be supplier-specific. The driver or operator is instructed to park in ventilated areas and to report any visible leak from the relief device or manlid gasket.

10. Receipt and offloading. The receiving facility checks the seal number, tank pressure, and certificate of analysis before connecting the offloading line. The receiving tank is sampled from the top or recirculation loop for water, density, and appearance before acceptance. Offloading is performed under nitrogen padding with earthing continuity and a closed vapour balance. The receiving tank must be dry and free of amines, strong bases, and Lewis acids that can initiate ECH oligomerization. After offloading, the empty tank documentation is signed and the shipment record is closed.