Lab tests for activated carbon: ASTM, JIS and BIS methods
Standard activated carbon tests for iodine number, methylene blue, hardness, ash, moisture, density, pH and particle size, and how to compare lab results.
VMS Carbon technical team · 2 min read · Updated 31 October 2026
Activated carbon is bought on test results, so it helps to know which tests exist, what they measure and why the same carbon can show different numbers in different labs.
The main standards
- ASTM (American) methods are the most widely quoted in international trade.
- JIS K 1474 (Japanese Industrial Standard) covers a full set of activated carbon tests and is common in Asian trade.
- BIS (Bureau of Indian Standards) methods are used in India.
- AWWA B600 and B604 set requirements for powdered and granular carbon in drinking water treatment.
- CEFIC methods (European chemical industry) are used for some tests.
How every lot is tested
- A sample is taken from every lot
- Iodine number: how much it can adsorb
- Methylene blue: how it takes larger molecules
- Hardness, ash and moisture go on the report
Common tests
| Property | Common methods | What it tells you |
|---|---|---|
| Iodine number | ASTM D4607, JIS K 1474 | micropore adsorption capacity |
| Methylene blue | JIS K 1474, BIS methods | mesopore capacity, colour removal |
| Ball-pan hardness | ASTM D3802 | resistance to breaking into fines |
| Total ash | ASTM D2866 | mineral content |
| Moisture | ASTM D2867 | water content |
| Apparent density | ASTM D2854 | weight per volume for bed design |
| Particle size | ASTM D2862 | sieve distribution of granules |
| pH | ASTM D3838 | pH of water in contact with carbon |
| Butane activity | ASTM D5742 | vapour capacity (gas phase) |
Why numbers differ between labs
- Different methods. Methylene blue in mg/g and in ml/g are not the same scale; iodine methods differ in detail.
- Particle size. Many tests grind the sample first; others test it as received.
- Moisture. Results may be on a dry or as-received basis.
- Sampling. A small sample from one bag may not represent a lot; proper sampling takes increments from many bags.
A good certificate of analysis
Ask that each lot's certificate states:
- lot number and production date;
- each result with its method and basis (dry or as received);
- the specification limits next to the results;
- the lab and signatory.
Testing in your own process
Standard tests compare carbons with each other. They do not predict exactly how a carbon performs on your water, oil or gas. For that, run an application test: a jar test for powder, a small column test for granules, a breakthrough test for gas phase.
Every lot we ship has a report for iodine number, methylene blue, hardness, moisture and ash to ASTM, JIS or BIS methods. Ask for a data sheet or a sample.
Frequently asked questions
Which test best predicts colour removal?
Methylene blue or a molasses decolorizing test, both of which reflect mesopores, rather than iodine number.
Can I compare an ASTM iodine number with a JIS one?
Roughly, but not exactly. Ask both suppliers to report by the same method if the numbers are close.
How should a sample be taken from a delivery?
Take small amounts from several bags across the lot and combine them, rather than one scoop from one bag.
