There's no single global quality standard for coco peat. What you meet as a buyer is a set of test methods (the European EN series for growing media, the Indian coir pith standards, and US extension-lab practice) plus whatever limits a supplier or a voluntary quality mark sets on top. The number on a spec sheet only means something when you know which method produced it, so the first thing to ask for on any sheet is the method behind each figure.
Standards set methods, contracts set limits
Most of the documents a buyer runs into are method standards. They tell a lab how to take a sample, how much water to add, how long to wait and what temperature to correct to. They don't say what EC coco peat should have. The pass or fail line comes from somewhere else: your purchase contract, a supplier's own grade bands, a national product standard, or a voluntary mark.
The Indian coir pith block standard is the exception, because it grades the product by EC.
The European EN test methods for growing media
The EN methods are written for "soil improvers and growing media" in general, so they cover coir, peat, bark and blends with the same procedures. That's their strength. A coir result and a peat result made under the same EN method can be compared directly.
| Standard | What it measures | How, in short | What it tells you about coco peat |
|---|---|---|---|
| EN 12579 | Sampling | How to take a representative sample from a lot | Whether the sample tested actually stands for your shipment |
| EN 13040 | Sample preparation, dry matter, moisture, laboratory compacted bulk density | Dry matter by oven at 103 ± 2 °C. Compacted bulk density in a 1 litre cylinder | Moisture and how much dry coir you get per litre |
| EN 13037 | pH | Water extract at 1+5 by volume, 22 ± 3 °C, read with a pH meter | Acidity. Washed coir rarely fails here |
| EN 13038 | Electrical conductivity | Water extract at 1+5 by volume, 22 ± 3 °C, result corrected to 25 °C | Soluble salts. The figure behind "low EC" claims, at this dilution |
| EN 13652 | Water-soluble nutrients and elements | Water extract at 1:5 by volume | Potassium, sodium, chloride and other ions available to roots |
| EN 13039 | Organic matter and ash | Dry at 103 ± 2 °C, ignite at 450 ± 25 °C. Organic matter is the loss on ignition | Ash content flags sand and soil contamination |
| EN 13041 | Dry bulk density, water volume, air volume, shrinkage, total pore space | Saturate, then equilibrate in rings at a suction of 10 cm water column | How the substrate holds water and air in a pot or slab |
| EN 15428 | Particle size distribution | Air-dried sample shaken through a sieve stack, mass on each sieve reported on a dry basis | The fines-to-coarse balance of the grade |
| EN 12580 | Quantity (volume) of loose product | Volume worked out from weight and a measured bulk density | Whether a bag of loose material holds the litres declared |
Two scope notes matter for coir. EN 13041 covers particles up to 25 mm and flexible fibres up to 80 mm, so most pith grades fit. And the EN 12580 volume method doesn't apply to material sold as blocks by dimension, which falls under EN 15761 instead. Several of these standards are under revision, so check the edition date on any lab report.
The air and water figures from EN 13041 are where coir grades really differ. If you want more on that side, see the guide to coco peat particle size grades.
The Indian coir pith standards
India has two standards that a coco peat buyer will meet.
IS 17739 covers raw coir pith, the material left after fibre is extracted from the husk. Its 2024 revision added test methods for pH and electrical conductivity of coir pith.
IS 19103:2025 is the specification for coir pith blocks. It grades blocks by EC:
| Grade | Name | EC (dS/m) |
|---|---|---|
| Grade I | Low EC | below 0.5 |
| Grade II | Medium EC | 0.5 to 0.8 |
| Grade III | High EC | above 0.8 |
One dS/m is the same as one mS/cm, so these bands line up with the "below 0.5 mS/cm" language on most coir data sheets. They're also close to the trade's informal low, medium and high EC split, which is handy. A supplier can tell you which grade a block falls into, and you know what that means without a conversion.
Ask which extraction ratio the EC was measured at, though. A grade band is only comparable to your own test if you use the same ratio.
US practice: saturated media extract and ASTM sieves
North American greenhouse labs mostly test substrates with water extracts too, but different ones.
- Saturated media extract (SME). Distilled water is added until the sample is just saturated, it stands for about 30 minutes, then the liquid is drawn off and read. The method was developed to cope with the wide range of bulk densities found in greenhouse media, and many US labs treat it as their standard.
- 1:2 dilution. One part substrate to two parts distilled water by volume, left for 30 minutes.
- PourThru. Water is poured on top of a pot in the crop and the leachate collected from below. It's an in-crop monitoring tool, not a raw-material test.
For particle size, US labs use test sieves built to ASTM E11, so ask which sieve numbers or apertures a grade was screened on. Moisture and ash in peat follow ASTM D2974: moisture by drying at 105 °C, ash by igniting the dried sample at 440 °C (or 750 °C in the alternative method), with organic matter taken as 100 minus ash. Note the ignition temperature differs from the EN method, so ash figures from the two aren't strictly interchangeable.
Why the same coco peat gives different numbers
More water in the extract means more dilution. The same sample reads highest by saturated extract, lower at 1:1.5, lower again at 1:2 and lowest at 1:5. pH moves far less between methods than EC does.
You can see the size of the gap in extension-service interpretation tables. These are the bands for a growing crop, not for raw coir, but they show how one root zone reads under each method:
| Indication | 1:2 (mS/cm) | SME (mS/cm) | PourThru (mS/cm) |
|---|---|---|---|
| Low | 0.26 to 0.75 | 0.76 to 2.0 | 1.0 to 2.6 |
| Normal | 0.76 to 1.25 | 2.1 to 3.5 | 2.7 to 4.6 |
| High | 1.26 to 1.75 | 3.6 to 5.0 | 4.7 to 6.5 |
A reading of 1.3 is "high" by 1:2 and "low" by SME. Same pot.
The 1:1.5 volume extract sits between 1:2 and SME. It's the Dutch method for peaty substrates and the one behind most coir data sheets. In a comparison of 1:1.5, 1:2, 1:5 and 1:10 extracts against the saturated extract on coir, the saturated and 1:1.5 extracts came out as the most useful for judging nutrients. Another study across a range of commercial substrates preferred 1:2. So researchers don't fully agree, and there's no reliable factor for converting one ratio to another on coir. Don't convert. Ask for the method you want, or test both sheets' samples yourself by one method. The step-by-step sample test walks through the 1:1.5 procedure.
Published ranges for coir
These figures come from studies of coir dust from several producing countries. They show how wide raw material varies, which is exactly why a sheet without a method is hard to use.
| Property | Published range | Method or basis |
|---|---|---|
| pH | 5.6 to 6.9 | 12 sources from three countries |
| EC | 0.3 to 2.9 mS/cm | Same 12 sources |
| Salinity | 0.39 to 5.97 mS/cm | Saturated media extract, 13 coir dusts |
| Dry bulk density | 0.04 to 0.08 g/cm³ | Five sources |
That salinity spread is why EC by a stated method is the first line of any coir spec.
How to ask for the method on a spec sheet
Put the method next to every number. A line like this tells you something:
EC 0.4 mS/cm, 1:1.5 volume extract, demineralised water, corrected to 25 °C
A line that only says "EC below 0.5" doesn't. When you send an enquiry, write the method into the request:
- EC and pH by 1:1.5 volume extract (or by EN 13037 and EN 13038 at 1+5, if that's what your lab runs).
- Moisture on a wet basis, oven-dried.
- Expansion in litres per kg, saying whether per kg as delivered or per kg dry.
- Particle grade by sieve size, with the sieve apertures named.
- Sodium and chloride if the coir will be used at a high share of a mix.
Units trip people up. 1 mS/cm = 1 dS/m = 1 mmho/cm = 1,000 µS/cm. They're the same number in different clothes.
What a product data sheet should contain
| Item | Why you need it |
|---|---|
| Product name, grade and format (block, briquette, slab, loose) | Ties the sheet to what you're buying |
| EC with extraction method and units | The main washing indicator |
| pH with extraction method | Usually unremarkable, but needed for blending |
| Treatment: washed, buffered or neither | Changes how the coir behaves with your feed. See buffered vs unbuffered |
| Moisture at dispatch, wet basis | Affects how much dry coir you're paying for |
| Expansion volume and its basis | Per kg delivered or per kg dry |
| Particle grade with sieve sizes | Decides water and air balance |
| Block or bale dimensions and weight | Logistics and price per litre |
| Sodium, potassium, chloride (if tested) | Matters at high inclusion rates |
| Sample date and lot reference | A sheet is a snapshot, not a promise for every lot |
Moisture deserves its own check. Two blocks of the same gross weight can hold quite different amounts of coir, and the moisture and weight guide shows how to correct for it.
Comparing two suppliers' sheets fairly
Line the sheets up only after you've done these checks.
- Same extraction method for EC and pH. If one says 1:1.5 and the other 1:5, the 1:5 figure will look better for no real reason.
- Same units. Convert µS/cm to mS/cm before you compare.
- Same moisture basis. Wet basis and dry basis give different numbers for the same block.
- Same expansion basis. Litres per kg dry will always beat litres per kg delivered.
- Typical or maximum? "Typical EC 0.3" and "maximum EC 0.5" aren't the same promise.
- Same grade. A fine pith and a chip blend shouldn't be judged on one water-holding figure.
Then test samples of both yourself, by one method, on the same day. That's the only comparison that removes the paperwork from the equation.
Voluntary quality marks
On top of the legal minimum, the Dutch and German growing-media trades each run a voluntary quality mark. They're not import requirements, and plenty of unmarked coir is sold in both countries. The Dutch mark follows a product through the chain from raw material to delivery, with independent audits, and checks properties such as water uptake, air content, pH, EC, nutrients and purity. The German mark has criteria sheets for raw materials, including one for coir pith, fibre and chips, that set limits on pH, salt, sodium and chloride for coir used as a substrate. The Germany and Netherlands import guide covers what that means in practice.
Without a mark, the testing burden moves to you, so the method on the sheet matters even more.
Working with CVM
CVM Fiber and Industries makes coco peat in Kanyakumari, Tamil Nadu, India. Our coco peat is washed with water to reduce EC, with no calcium nitrate or other chemicals added, and it isn't buffered. If you're drafting a specification and want to talk through which methods and figures to put on it, get in touch.
FAQ
Is there an international standard for coco peat?
No single one. Buyers meet a mix of method standards, such as the European EN series for growing media, and product specifications like the Indian coir pith block standard. Limits usually come from the contract, the supplier's grades or a voluntary quality mark.
What does IS 19103 say about coir pith block EC?
It grades coir pith blocks by EC into three bands. Grade I (low EC) is below 0.5 dS/m, Grade II (medium) is 0.5 to 0.8 and Grade III (high) is above 0.8. One dS/m equals one mS/cm.
What is the difference between IS 17739 and IS 19103?
IS 17739 covers raw coir pith as it comes from fibre extraction, and its 2024 revision added pH and EC test methods. IS 19103 is the specification for compressed coir pith blocks and grades them by EC.
Which extraction ratio do EN 13037 and EN 13038 use?
Both use a water extract at 1+5 by volume at 22 ± 3 °C. EN 13037 reads pH in the suspension and EN 13038 reads conductivity in the extract, corrected to 25 °C.
Why is my EC reading higher than the supplier's data sheet?
Usually because you used less water than they did. A saturated extract or a 1:1.5 extract reads higher than a 1:5 extract on the same sample. Check the method on the sheet and retest by that method before raising a claim.
Can I convert a 1:5 EC to a 1:1.5 EC?
Not reliably for coir. The relationship shifts with the material and its salts, and studies don't agree on a factor. Ask for results by the method you use or test both samples yourself by one method.
Do I need a quality mark to sell coco peat in Europe?
No. The Dutch and German marks are voluntary. Unmarked coir is sold in both markets, but the buyer then carries the batch testing, usually EC, pH, sodium and chloride on each lot.
What should a coco peat data sheet always include?
At minimum EC and pH with the extraction method, the treatment (washed, buffered or neither), moisture on a wet basis, expansion with its basis, particle grade by sieve size, format and weight, and a lot reference with a sample date.