How to Buy Maleic Anhydride from China:
Supplier Guide, Shipping & Documentation
Supplier qualification · COA verification · DG Class 4.1 freight · REACH/TSCA docs · Incoterms · QC release
🔗 Request Quote from Sinolook Chemical📋 Table of Contents
- The Complete Buying Journey: Overview
- Supplier Selection: What to Look For
- Sampling & Qualification: From Lab Test to Production Trial
- Specification and Purchase Contract
- Packaging Options: Bags, Big Bags and Molten ISO Tank
- Incoterms Guide for MAH Purchases from China
- Class 4.1 DG Sea Freight: What to Expect
- Complete Documentation Checklist
- Receiving & In-House QC Release
- Common Purchasing Errors and How to Avoid Them
- Frequently Asked Questions
🗺️ 1. The Complete Buying Journey: Overview
📋 End-to-End MAH Purchase Process from China
Total timeline: first purchase typically 6–10 weeks from initial contact to goods receipt (China → Europe); repeat orders 3–6 weeks
⚠️ MAH-specific buying consideration vs liquid chemicals (IOA, NDA, etc.): Unlike liquid acid chemicals that ship in drums or IBCs, solid MAH ships in 25 kg bags or big bags that are moisture-sensitive and must remain sealed throughout transit. Bags must be inspected for damage on arrival before QC testing - moisture-damaged bags will show caking, hard lumps, or yellow discolouration, and the crystallisation point will be suppressed below 52°C. This is the unique quality risk in MAH purchasing that does not apply to liquid acid products.
🔍 2. Supplier Selection: What to Look For
The Chinese MAH supply chain includes genuine n-butane oxidation producers, traders sourcing from producers, and occasionally companies offering lower-grade or mislabelled material. A structured evaluation distinguishes genuine producers and qualified traders from less reliable sources.
- Hazardous Chemical Production Licence (危险化学品生产许可证) - for producers; legal requirement for MAH manufacture in China; ask to see licence number and verify
- n-Butane oxidation capability - genuine producers can describe their VPO catalyst system, reactor type (fixed-bed or fluidised-bed), and production capacity; traders cannot
- Batch COA with real values - actual measurements like "52.6°C crystallisation point" and "APHA 18" look different from nominal round numbers like "52.5°C" and "≤20"; real lab data is distinguishable
- DG documentation capability - must be able to provide Class 4.1 DGD signed by certified DG dangerous goods safety adviser; inability to produce DGD is a disqualifying flag
- Retention sample policy - genuine producers hold batch retention samples; traders typically cannot trace back to specific production batches
- REACH OR and TSCA documentation - legitimate export-oriented suppliers maintain these; absence suggests limited export experience
- Price below $700/MT FOB - probable off-spec, blended, or mislabelled product; genuine MAH cannot be produced at this price with adequate quality
- Crystallisation point exactly 52.5°C on every COA - real batches land at values like 52.6°C or 52.7°C; consistently hitting exactly the minimum spec suggests fabricated data
- Cannot provide DGD - MAH is Class 4.1 DG and cannot legally be shipped without proper DG documentation; inability to provide DGD means the supplier cannot export compliantly
- No hazardous chemical production licence - cannot legally manufacture MAH in China
- COA shows maleic acid as primary chemical - some suppliers confuse or conflate maleic acid (CAS 110-16-7) and maleic anhydride (CAS 108-31-6); always verify CAS on the COA
- APHA always "≤30" with no actual measured value - COAs should show measured values, not just specification limits
| Company registration (营业执照) | Request copy |
| Hazardous Chem. Production Licence | For producers |
| 3–5 recent batch COAs | Verify cryst. pt, APHA, CAS |
| GHS SDS (EN or local language) | Check H334, H314 present |
| REACH OR letter availability | CAS 108-31-6 |
| TSCA cert. availability | US buyers |
| DGD issuance capability | Class 4.1, UN 2215 |
| Sample availability (0.5–5 kg) | DG courier (limited qty) |
🧪 3. Sampling & Qualification: From Lab Test to Production Trial
| Stage | Quantity | Tests to Conduct | Pass Criteria | Decision Gate |
|---|---|---|---|---|
| Stage 1: Lab QC | 0.5–2 kg | Crystallisation point (ASTM E794); APHA colour on melt at 70°C (ASTM D1209); maleic acid content by GC-FID (acetone solution); visual appearance (colour, lumps) | Cryst. pt ≥52.5°C; APHA within spec; maleic acid ≤0.3%; white, free-flowing flakes | Pass all → Stage 2; Fail any → reject this supplier/lot |
| Stage 2: Identity Check | 0.5 kg | FTIR: confirm twin C=O bands at 1,780 + 1,850 cm⁻¹ (cyclic anhydride); confirm CAS 108-31-6 not maleic acid (110-16-7); purity by titrimetric method | FTIR doublet confirmed; purity ≥99.0%; no maleic acid FTIR pattern (peak at 1,710 cm⁻¹ absent) | Pass → Stage 3; Fail → reject (wrong product) |
| Stage 3: Synthesis Trial | 2–5 kg | Pilot synthesis with Chinese MAH at your process (UPR, HPMA, SMA, or grafting). Compare: Acid Number (UPR), APHA colour of product, molecular weight, and performance (gel time, scale inhibition, Tg) against your current MAH baseline | AN, colour, and performance match current baseline ±5%; no premature gelation; no colour exceedance | Pass → Stage 4; Fail → investigate Fe, maleic acid, or purity root cause |
| Stage 4: Full Production Trial | 25–200 kg | Full commercial-scale synthesis batch; full QC on finished product to specification; confirm no scale-up surprises; update SOPs if MAH grade changes (e.g., adjust glycol charge if maleic acid content differs) | All finished product parameters within spec | Pass → approve Chinese MAH as standard/alternate source; update AVL |
📝 4. Specification and Purchase Contract
| Parameter | Specification | Method |
|---|---|---|
| CAS / Identity | CAS 108-31-6 | FTIR / COA |
| Crystallisation point ⭐ | ≥ 52.5°C | ASTM E794 |
| Purity (MAH%) ⭐ | ≥ 99.0% | Titrimetric |
| Colour (APHA, molten 70°C) | ≤ 30 | ASTM D1209 |
| Maleic acid content | ≤ 0.3% | GC-FID |
| Iron (Fe) | ≤ 5 ppm | ICP-OES |
| Ash | ≤ 0.005% | ASTM D482 |
| Appearance | White solid flakes; free-flowing; no lumps | Visual |
| Parameter | Premium Spec | Use Case |
|---|---|---|
| Purity ⭐ | ≥ 99.5% | Gel-coat UPR; SMA |
| Colour (APHA) ⭐ | ≤ 10 | Gel-coat; ink varnish |
| Iron (Fe) ⭐ | ≤ 1 ppm | Gel-coat UPR; SMA PC |
| Maleic acid | ≤ 0.1% | All premium apps |
| Cryst. point | ≥ 52.6°C | Tighter purity QC |
| Packaging | PE-lined bags; N₂-flushed inner PE | Moisture exclusion |
Premium grade costs approximately 20–30% more than standard; only specify for applications where APHA ≤10 and/or Fe ≤1 ppm are genuine rejection criteria.
📄 Key Contract Clauses for MAH Purchase
📦 5. Packaging Options: Bags, Big Bags and Molten ISO Tank
| Packaging | Net per Unit | Units per 20ft | Best For | Key Advantages & Limitations |
|---|---|---|---|---|
| 25 kg PE-lined bag | 25 kg | ~580 bags (~14.5 MT) | Small–mid users; 1–15 MT orders; flexible stock management | ✅ Standard; widely available; easy lot splitting ⚠️ Higher per-MT cost; bag disposal; manual handling; dust generation at bag-tipping |
| 500 kg FIBC big bag | 500 kg | ~26 bags (~13 MT) | Mid-size users; ≥5 MT orders; requires FIBC discharger | ✅ Lower per-MT cost than 25 kg bags; less dust if enclosed discharge ⚠️ Requires FIBC discharger + melt vessel; FIBC disposal |
| 1,000 kg FIBC big bag | 1,000 kg | ~13 bags (~13 MT) | Larger users; ≥10 MT orders; maximises bag economy | ✅ Best bag economy; fewer lifts ⚠️ Requires appropriate forklift capacity and FIBC discharger rated for 1,000 kg |
| Molten ISO tank ⭐ | ~18–20 MT | 1 ISO tank | Large UPR producers; ≥18 MT per order; requires heated tank farm | ✅ Lowest per-MT price; no packaging waste; direct pump-to-reactor; eliminates solid handling and dust hazard entirely ⚠️ Requires on-site heated SS316L MAH storage tank + heat-traced pipework; ISO tank rental cost |
🚢 6. Incoterms Guide for MAH Purchases from China
| Incoterm | DG Booking Responsibility | Who Pays Freight | Risk Transfer | Best For |
|---|---|---|---|---|
| FOB | Buyer books freight; Sinolook loads and provides DGD | Buyer pays ocean freight + DG surcharge + insurance | On board vessel at Chinese port | Buyers with experienced DG freight forwarder; price transparency; larger volumes |
| CIF ⭐ | Sinolook handles Class 4.1 DG booking end-to-end | Sinolook pays freight + insurance to named destination port | On board vessel | Recommended for first-time buyers - Sinolook manages Class 4.1 complexity; buyer handles import clearance only |
| CFR | Seller books freight; buyer arranges own insurance | Seller pays freight to destination; buyer pays insurance | On board vessel | Buyers with blanket marine DG insurance policies; similar to CIF otherwise |
| EXW | Buyer arranges all logistics from Sinolook's warehouse in China | Buyer pays all freight from warehouse | At seller's warehouse | Not recommended for first-time buyers - buyer must manage Chinese DG export documentation; complex for non-China-based buyers |
💡 Recommendation for first-time China MAH buyers: Use CIF to your nearest major port. Sinolook Chemical manages the Class 4.1 DG booking, container labelling, DGD, CPC, and all Chinese export documentation for solid MAH. You only arrange: customs clearance at your destination port + inland delivery. CIF gives you a total landed cost directly comparable to your Western supplier's delivered price - making the business case for switching straightforward.
🚢 7. Class 4.1 DG Sea Freight: What to Expect
| UN Number | UN 2215 |
| Proper Shipping Name | MALEIC ANHYDRIDE |
| Class | 4.1 (Flammable solid) |
| Packing Group | III |
| EmS | F-A, S-G |
| Stowage | Category A |
| Packaging (bags) | UN-marked fibreboard boxes or drums (4G or 1A2); inner PE bags; Class 4.1 label on outer |
- Not Class 8 like NDA/IOA: MAH ships as Class 4.1 (flammable solid) - a different hazard class and DG documentation set from liquid corrosive acids. Buyers accustomed to ordering NDA/IOA (Class 8) must ensure their freight forwarder and import broker are briefed on the Class 4.1 classification
- Container type: Standard 20ft dry container; bags are palletised and shrink-wrapped; no heated container needed for solid MAH (unlike molten ISO tank shipments)
- Moisture in container: Containers with history of water ingress or with high humidity can damage MAH bags; specify container must be dry and undamaged
- Segregation: MAH must be segregated from oxidisers and corrosives in the same container or hold
- DG surcharge: Shipping lines charge Class 4.1 DG surcharges of $150–400/20ft in addition to standard ocean freight
| Order → COA + production | 7–14 days |
| DG booking → container loading | 3–7 days |
| Transit China → N. Europe | 28–35 days |
| Customs clearance (DG) | 2–5 days |
| Inland delivery | 1–3 days |
| Total (Europe) | ~6–9 weeks ⭐ |
China → ME/South Asia: 3–5 weeks; China → SE Asia: 2–3 weeks; China → Americas: 5–8 weeks
📁 8. Complete Documentation Checklist
| COA (batch) ⭐ | Cryst. pt, purity, APHA, maleic acid, Fe; batch no. matching bags |
| GHS SDS ⭐ | 16-section; H314, H334 confirmed; Section 14: UN 2215, Class 4.1 |
| DGD ⭐ | Class 4.1, UN 2215, PG III; signed DG Safety Adviser |
| CPC | Container Packing Certificate |
| Commercial Invoice + Packing List | Customs value + quantity |
| Bill of Lading | 3 originals; Class 4.1 DG stated |
| Certificate of Origin | HS 2917.14 |
| REACH OR Letter ⭐ | Confirms CAS 108-31-6 registered; names EU OR; per shipment |
| GHS SDS in EU language | German, French, Dutch, etc.; REACH Annex II / Reg. 2020/878 |
| EU DG import notification | Check country-specific DG import requirements; most EU countries use standard customs procedure for Class 4.1 PG III |
| TSCA Positive Cert. ⭐ | Confirms CAS 108-31-6 on TSCA Active Inventory; per shipment; for US Customs (CBP) |
| OSHA HazCom 2012 SDS | ANSI Z400 format; English; Section 14 with UN 2215 |
| DOT classification | FLAMMABLE SOLID, NOS (Maleic anhydride), UN 2215, PG III |
🔬 9. Receiving & In-House QC Release
- Count bags/big bags; confirm quantity matches packing list
- Inspect bags: any torn, wet, or deformed bags → segregate immediately; moisture-damaged MAH cannot be used without full re-testing
- Check bag labels: product name "Maleic Anhydride", CAS 108-31-6, Class 4.1 UN 2215, batch number
- Confirm batch number on labels matches batch number on COA
- Visual appearance of one opened bag (sample for QC): white free-flowing flakes expected; yellow/grey discolouration or hard lumps → run Fe ICP before releasing
| Test | Frequency | Time |
|---|---|---|
| Crystallisation point ⭐ | Every batch | 20 min |
| APHA colour (molten) | Every batch | 15 min |
| Maleic acid (GC or titr.) | Every batch | 30 min |
| Purity (titrimetric) | Every 3rd batch | 30 min |
| Iron (ICP-OES) | Quarterly or new lot | 1–2 days |
⭐ Crystallisation point is the single most important incoming QC test for MAH - takes 20 minutes and detects the most common quality failure (moisture damage).
⚠️ 10. Common Purchasing Errors and How to Avoid Them
| Common Error | Why It Happens | How to Avoid |
|---|---|---|
| Ordering maleic acid (110-16-7) instead of maleic anhydride (108-31-6) | CAS numbers differ by one digit; some Chinese suppliers list both products; procurement team specifies "maleic" without CAS confirmation | Always include CAS 108-31-6 explicitly on PO; verify CAS on COA before releasing to production; FTIR the first batch to confirm twin anhydride C=O bands at 1,780 + 1,850 cm⁻¹ |
| Skipping the crystallisation point test on received MAH | Team measures purity by titration only; does not realise that moisture damage during shipping lowers crystallisation point before it noticeably affects purity measurement | Make crystallisation point the mandatory first QC test on every received batch - it takes 20 minutes and catches moisture damage that purity titration alone misses |
| Treating MAH as Class 8 DG (like IOA or NDA) at import | Procurement buyer previously handled NDA/IOA (Class 8 corrosive liquids); wrongly applies Class 8 import procedures to MAH; creates customs clearance problems | MAH is Class 4.1 (flammable solid), UN 2215 - completely different from Class 8 corrosive liquids. Brief import broker and warehouse team on the Class 4.1 classification before first shipment |
| Storing MAH bags in humid or warm warehouse conditions | Chemical warehouse allocates standard storage bay without noting MAH's moisture sensitivity; bags stored near loading dock in summer heat; caking occurs within weeks | Store MAH in dedicated cool (<30°C), dry (<60% RH) area, away from heat sources and water pipes; do not open bags until needed; FIFO stock rotation; test crystallisation point on any bags stored >6 months |
| Not adjusting UPR recipe stoichiometry for different MAH purity | Switch from 99.5% Western MAH to 99.0% Chinese MAH without adjusting glycol charge; UPR has slightly different AN than expected | Always use actual batch purity from COA in stoichiometry calculation; a 0.5% purity difference shifts the effective anhydride equivalents per kg by ~0.5% - negligible for most applications but worth correcting for tight AN targets |
| Using water or water mist to extinguish solid MAH fires | EHS team not briefed on MAH's dual fire hazard; uses water jet standard response; does not know about the spattering risk with hot or molten MAH | Train EHS and fire response team specifically on MAH: CO₂ and dry powder for small fires; water jets on molten MAH fires cause violent spattering; update site emergency response plan to include Class 4.1 flammable solid procedures |
❓ 11. Frequently Asked Questions
Q1: How do I start buying maleic anhydride from Sinolook Chemical?
Starting the process with Sinolook Chemical is straightforward. Send an enquiry to sales@sinolookchem.com or WhatsApp 0086 18150362095 with: (1) Product: Maleic Anhydride, CAS 108-31-6; (2) Grade: Standard (APHA ≤30, purity ≥99.0%) or Premium (APHA ≤10, Fe ≤1 ppm); (3) Quantity: required per order and estimated annual volume; (4) Packaging: 25 kg bags, 500/1,000 kg FIBC big bags, or molten ISO tank; (5) Destination port; (6) Incoterms preference (CIF recommended for first purchase); (7) Required documents: REACH OR letter (EU buyers), TSCA certification (US buyers), SDS language. We respond with a firm CIF quotation, sample batch COA, and SDS within 24 hours. Samples (0.5–5 kg) are available for laboratory qualification - shipped as DG limited quantities by international courier with full Class 4.1 documentation. Full details of our MAH product at sinolookchem.com/personal-care-chemicals/maleic-anhydride.html
Q2: What documents does Sinolook Chemical provide with MAH shipments?
Sinolook Chemical provides the following documentation as standard with every MAH shipment, included in the quoted price: (1) Batch COA - with measured values for crystallisation point, purity, APHA colour (molten at 70°C), maleic acid content, Fe (on premium grade), and ash; batch number matching all bag/big bag labels; (2) GHS SDS in your requested language - 16-section REACH Annex II format; confirms H314, H317, H334, H335, H372 classifications; Section 14 with UN 2215, Class 4.1, PG III; (3) Dangerous Goods Declaration (DGD) - IMDG Class 4.1, UN 2215, PG III; signed by our certified DG Dangerous Goods Safety Adviser; (4) Container Packing Certificate (CPC) - confirming packing per IMDG requirements; (5) Commercial Invoice and Packing List; (6) Bill of Lading (3 originals); (7) Certificate of Origin. Additionally on request: REACH OR Confirmation Letter (EU buyers) and TSCA Positive Certification (US buyers) - both provided as standard for these destinations.
Q3: What is the minimum order quantity (MOQ) for maleic anhydride from Sinolook Chemical?
Sinolook Chemical's minimum order quantities for maleic anhydride are: 25 kg bag orders: 1 MT (approximately 40 bags, one full pallet); FIBC big bag orders: 5 MT (10 × 500 kg bags or 5 × 1,000 kg bags); Molten ISO tank: 18 MT (one full ISO tank, best economy). For initial qualification purchases, we supply smaller quantities (0.5–5 kg) as laboratory samples at sample pricing - dispatched by international courier as DG limited quantities (Class 4.1). For regular buyers committing to annual volume contracts (typically ≥20 MT/year), we discuss preferential pricing, priority production scheduling, and guaranteed availability. Contact us with your required grade, quantity, packaging preference, and destination port for a firm quotation within 24 hours.
Q4: What QC test should I do first when MAH arrives from China?
The single most important incoming QC test for maleic anhydride is the crystallisation point measurement - it takes approximately 20 minutes and detects the most common quality failure in shipped MAH: moisture damage during transit. The test procedure: take approximately 5–10 g of MAH flakes from one bag; melt at 65°C in a glass test tube; insert a calibrated thermometer; allow to cool slowly while gently stirring; record the temperature at which the first crystals appear (the crystallisation point). This must be ≥52.5°C for standard grade (≥52.6°C for premium). A crystallisation point below 52.0°C indicates significant maleic acid contamination from moisture hydrolysis - reject the batch and contact Sinolook for investigation. After the crystallisation point, measure APHA colour on the molten sample while it is still liquid at 70°C (takes 10–15 additional minutes). Between these two tests (total ~35 minutes), you have confirmed the two most critical quality parameters - moisture integrity and colour - before releasing the batch to production. For colour-critical applications (gel-coat UPR, SMA personal care), also run Fe by ICP-OES on the first bag from each new production lot.
Q5: Can Sinolook Chemical ship maleic anhydride to my country?
Sinolook Chemical has shipped maleic anhydride to customers in more than 50 countries, including: Europe (Germany, Netherlands, Belgium, France, UK, Italy, Spain, Poland, Turkey, Romania); Middle East (UAE, Saudi Arabia, Kuwait, Egypt, Jordan); South Asia (India, Pakistan, Bangladesh, Sri Lanka); Southeast Asia (Vietnam, Thailand, Indonesia, Malaysia, the Philippines, Singapore); East Asia (South Korea, Taiwan); South America (Brazil, Chile, Colombia, Peru); Africa (South Africa, Kenya, Nigeria, Morocco, Algeria); and North America (USA, Canada, Mexico). For each destination, we manage the Class 4.1 DG documentation chain required by IMDG. Country-specific notes: certain countries require DG import permits in advance for Class 4.1 solids - advise us of your destination and we will flag any pre-import permit requirements we are aware of; EU customers receive REACH OR letter as standard; US customers receive TSCA positive certification as standard. If you have a specific destination in mind, contact us at sales@sinolookchem.com or WhatsApp 0086 18150362095 with your port of destination and we will confirm feasibility, estimated transit time, and a CIF price within 24 hours.
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MAH CAS 108-31-6 · Standard (APHA ≤30, ≥99.0%) & Premium (APHA ≤10, Fe ≤1 ppm)
25 kg bags · FIBC big bags · Molten ISO tank · REACH OR ✅ · TSCA cert ✅ · Class 4.1 DG docs · 50+ countries
