Coconut Shell Activated Carbon Iodine Specifications Guide
If you are a procurement buyer responsible for selecting coconut-shell activated carbon (CSAC) for a municipal water-treatment plant, gold-recovery refinery, or industrial air-purification system, the first decision you face is the iodine-number specification. Iodine number is the most widely accepted indicator of a carbon’s microporous surface area and directly determines adsorption capacity, breakthrough time, and operating cost. This guide delivers a data-driven framework for evaluating iodine number, interpreting certificates of analysis (COAs), and negotiating price and compliance across key markets.
What is the iodine number and why it matters for coconut-shell activated carbon
Iodine number is a laboratory test that measures the amount of iodine (in mg g⁻¹) adsorbed by a carbon sample at 25 °C, 10 min, and 1 atm. The value is a proxy for micropore volume and is the single most reliable spec for CSAC used in water treatment, gold-recovery, and air-purification.
| Application | Target iodine-number range (mg g⁻¹) | Typical surface area (m² g⁻¹) |
|---|---|---|
| Municipal water treatment | 600 – 800 | ~600-800 |
| Gold-recovery (high-adsorption) | 900 – 1,100 | ~900-1,100 |
| Air-purification / odor control | 600 – 900 | 600-900 |
Higher iodine numbers give longer breakthrough times for a given column volume, reducing replacement frequency and extending media life.
Standard test methods and how to read a COA
| Test | ASTM standard | What to look for | Typical CSAC values |
|---|---|---|---|
| Iodine number | ASTM D4607 | mg g⁻¹ | 600 – 1,100 |
| Moisture | ASTM D2867 | % | < 2 % (granular), < 1.5 % (powder) |
| Ash content | ASTM D2866 | % | < 5 % (water), < 3 % (gold) |
| Hardness / abrasion | ASTM D3802 | % weight loss | < 3 % |
| pH (in water) | ASTM D3838 | pH | 6 – 8 |
A COA that cites ASTM D4607 for iodine number is the benchmark. If a COA lists a different method, request clarification or a re-test.
Example COA snippet
Test Method: ASTM D4607
Iodine Number (mg/g): 920
Moisture: 1.2%
Ash: 2.8%
Hardness (ASTM D3802): 2.5% loss
pH (in water): 6.7
This COA indicates a CSAC suitable for gold-recovery or high-purity water treatment.
Typical iodine-number ranges and associated grade classifications
| Grade | Iodine Number (mg g⁻¹) | Mesh Size | Ash % | Moisture % | Hardness % loss | pH | HS Code | Typical MFN Duty | Packaging |
|---|---|---|---|---|---|---|---|---|---|
| Water-Treatment (Standard) | 600 – 800 | 4 – 8 mesh | < 5 % | < 2 % | < 3 % | 6 – 8 | 3802.10.0020 | US 4.8 % / EU 3.2 % / JP 3.3 % | 20-ft container, bulk bags (1 t) or drums |
| Gold-Recovery (High-Iodine) | 900 – 1,100 | 4 – 8 mesh | < 3 % | < 1.5 % | < 2 % | 6 – 7.5 | 3802.10.0020 | US 4.8 % / EU 3.2 % / JP 3.3 % | 20-ft container, bulk bags (1 t) or jumbo drums |
| Air/Odor (Fine Powder) | 600 – 900 | < 200 mesh | < 5 % | < 2 % | < 3 % | 6 – 8 | 3802.10.0020 | US 4.8 % / EU 3.2 % / JP 3.3 % | 20-ft container, bulk bags (0.5 – 1 t) or sealed drums |
All values are industry benchmarks as of mid-2026; actual supplier data should be verified via COA.
Duty rates and tariff programmes change. Every rate above is indicative only. Confirm the classification and the rate in force on your date of entry with your customs broker, against the USITC HTS (US) or TARIC (EU) databases.
Key complementary specifications: mesh size, ash content, moisture, hardness, pH
| Specification | Why it matters | Typical range for CSAC | Verification tip |
|---|---|---|---|
| Mesh size | Determines pressure drop and surface area; critical for column design. | 4 – 8 mesh (granular) or < 200 mesh (powder) | Request sieve analysis or particle-size field in COA |
| Ash content | High ash reduces active sites and can leach minerals. | < 5 % (water), < 3 % (gold) | Verify ASTM D2866 value in COA |
| Moisture | Affects bulk density, compaction, and handling. | < 2 % (granular), < 1.5 % (powder) | Check ASTM D2867 value |
| Hardness / abrasion | Influences column life and pressure drop. | < 3 % weight loss | Ensure ASTM D3802 value |
| pH (in water) | Impacts downstream chemistry and corrosion. | 6 – 8 | Measure after equilibrating carbon in de-ionized water |
Regulatory and trade considerations (AWWA/NSF standards, HS 3802.10, duties by market)
| Market | HS Code | MFN Duty | Relevant Standards | Notes |
|---|---|---|---|---|
| United States | 3802.10.0020 | 4.8 % (plus any Section 232/301 or other Chapter 99 measure in force on your date of entry - confirm with your customs broker) | ANSI/AWWA B604, NSF/ANSI 61 | Duty may vary with origin; verify tariff classification |
| European Union | 3802.10.0020 | 3.2 % MFN (preferential rate available under EVFTA with a valid statement on origin - confirm the current TARIC rate with your broker) | ANSI/AWWA B604, Directive (EU) 2020/2184 (Drinking Water) | Vietnam-origin goods claim preference under EVFTA, not GSP+ (Vietnam left the EU GSP scheme on 1 Jan 2023) |
| Japan | 3802.10.0020 | 3.3 % (0 % under RCEP for ASEAN + China) | ANSI/AWWA B604, JIS K 1474 | RCEP participants enjoy duty-free entry; confirm origin paperwork |
HS code 3802.10.0020 applies to coconut-derived activated carbon.
Pricing, MOQ, and packaging options for different iodine-grade CSAC
Pricing varies by grade, order volume, and market conditions. Minimum order quantities (MOQs) typically start at 1 ton in bulk bags or 5 tons in 20-ft containers. Packaging options include:
| Grade | Common packaging | Typical MOQ | FOB price range (USD / t) | Notes |
|---|---|---|---|---|
| Water-Treatment | 20-ft container, bulk bags (1 t) | 1 t | 1,200 – 1,600 | Bulk bags reduce handling cost |
| Gold-Recovery | 20-ft container, bulk bags (1 t) | 1 t | 1,400 – 1,800 | Higher iodine grade commands premium |
| Air/Odor | 20-ft container, bulk bags (0.5–1 t) | 0.5 t | 1,100 – 1,500 | Powder form requires tighter packaging |
FOB prices are indicative; consult suppliers for current market rates.
How to verify traceability and secure reliable supplier documentation
- Request a complete COA that lists iodine number, moisture, ash, hardness, pH, and test method (ASTM D4607, D2867, D2866).
- Verify third-party lab accreditation (NSF/ANSI, AWWA). Ask for the lab’s accreditation certificate and the test date.
- Obtain an origin certificate that complies with HS 3802.10.0020 and the MFN duty schedule of the destination country.
- Ship a sample for independent testing. A 25-50 kg representative sample can be sent via DHL (5-7 days) to a lab accredited to ASTM standards.
- Audit the production facility if the contract volume warrants it. On-site audits confirm raw-material sourcing, activation process, and quality control.
- Use a supply-chain traceability platform that tracks batch numbers and production dates.
These steps mitigate the risk of receiving carbon that does not meet the target iodine number or has hidden quality defects.
Practical tips for sample procurement and lab testing
| Tip | Detail |
|---|---|
| Sample size | Request at least 50 kg for a representative test; larger samples reduce intra-lot variability. |
| Storage | Keep samples in a dry, ventilated area at 20–25 °C to preserve moisture content. |
| Lab selection | Choose a lab accredited to ASTM standards; request a letter of accreditation. |
| Test frequency | For long-term contracts, schedule annual COA verification to detect drift in iodine number or ash content. |
| Documentation | Keep digital copies of all COAs, lab certificates, and audit reports in a central repository. |
Summary and next steps
- Iodine number is the primary spec for CSAC selection; target 600-1,100 mg g⁻¹ for water, 900-1,100 mg g⁻¹ for gold-recovery, and 600-900 mg g⁻¹ for air-purification.
- Complementary specs (mesh, ash, moisture, hardness, pH) must align with the application to ensure performance and regulatory compliance.
- Regulatory codes (AWWA, NSF/ANSI, HS 3802.10) and duty rates (US 4.8 %, EU 3.2 %, JP 3.3 %) shape landed cost and documentation requirements.
- Pricing and MOQ vary by grade; bulk bags and 20-ft containers are standard for large orders.
- Traceability is non-negotiable: secure COA, third-party certification, origin certificate, independent lab verification, and supply-chain tracking.
Use this guide to evaluate supplier proposals, negotiate terms, and ensure that the CSAC you procure delivers the required adsorption performance and compliance for your specific process.
Explore our detailed CSAC grade selection guide for deeper insight into application-specific specs.
Learn how to buy CSAC in bulk for cost-effective purchasing strategies.
Understand IMDG-2026 shipping requirements for coconut charcoal to streamline logistics.
Download our CSAC procurement checklist to verify every critical parameter before purchase.
Frequently Asked Questions
What iodine number should I look for when buying CSAC for municipal water treatment?
Answer: For municipal water-treatment, aim for an iodine number between 600 and 800 mg g⁻¹. This range balances adsorption capacity with acceptable ash and moisture levels for typical ANSI/AWWA B604 compliant systems.How do I verify that a supplier’s reported iodine number is accurate?
Answer: Request a COA that cites ASTM D4607 and obtain a third-party lab test on a sample. Compare the lab result to the supplier’s COA; a deviation of more than ±10 % warrants further investigation.Which mesh size is best for a rapid-mix adsorption column versus a fixed-bed column?
Answer: Rapid-mix columns benefit from finer particles (< 200 mesh powder) to increase surface area, while fixed-bed columns typically use 4-8 mesh granular carbon to maintain pressure drop and avoid channeling.What are the typical ash and moisture limits that affect carbon performance?
Answer: Ash content should be < 5 % for water-treatment and < 3 % for gold-recovery; moisture should stay below 2 % (granular) or 1.5 % (powder) to prevent bulk density loss and pressure drop.How do duties and HS-code classification impact the landed cost of CSAC in the US, EU, and Japan?
Answer: The HS code 3802.10.0020 attracts 4.8 % duty in the US, 3.2 % in the EU (preferential rate under EVFTA for Vietnam-origin goods), and 3.3 % in Japan (0 % under RCEP). These rates add to FOB and freight to determine the final landed cost.
Call to Action
- Request a quotation – tell us your grade, volume and destination port and we will come back with a price and delivery schedule.
- Request a sample – we ship A 25-50 kg representative sample via DHL (5-7 days) with a verified COA ready for your lab.
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