Hydrogen cyanamide 50% SL (CAS 420-04-2) is a product where the buying decision is mostly about age and documents, not about price per tonne. Two drums from the same producer can hold the same assay and differ in dicyandiamide by a factor of two – the difference between a fresh batch and one that has spent a summer in a warehouse. This guide covers the enquiry, the specification review, the packaging, the acceptance tests and the four traps.
Define These Before Asking for a Price
| Question | Why it changes the offer |
|---|---|
| Agricultural or industrial use? | Agricultural use is a plant-protection registration question in most markets; industrial use is not. The paperwork and the buyer’s own eligibility differ. |
| Which form? 50% SL or 95% crystalline | Different supply chains, different shelf life, and the crystal is quoted per enquiry because its specification is not published |
| Volume and pack? 25 kg trial, 200 kg drum, 1000 kg IBC | Drives price and shipping terms; the 50% solution moves as a non-flammable liquid in HDPE |
| Storage conditions at your site? | Hot climates, open-sided stores and shared warehouses all shorten the product’s useful life and should be declared |
| Documentation? COA, SDS, and any registration statement | Ask up front; a registration statement cannot be produced retrospectively for a shipment already at sea |
Reading the Specification
| Line item | What good looks like | What it tells you |
|---|---|---|
| Appearance | Colourless or light yellow clear liquid | Haze or sediment means dimerisation or contamination – reject or re-test |
| Cyanamide content | 50.0% min | The active you are buying; well above 50.0% on a fresh batch is normal |
| Dicyandiamide | 2.0% max | Age indicator. A fresh batch should be far below the limit – a batch sitting at 2.0% is old stock |
| pH | 3.8 – 5.4 | Stabiliser integrity. Above the band, dimerisation is accelerating |
| Dilution stability (200x) | Stable | Confirms the buffer holds at 0.25% cyanamide |
| Density | 1.065 – 1.095 g/mL | Converts the assay into grams per litre and cross-checks the assay |
| Batch date | Recent, stated | Not always on a template COA – ask for it explicitly |
The two numbers to compare across offers are dicyandiamide and pH, not the assay. Everyone can hit 50.0% min; not everyone ships a fresh, correctly buffered batch. If a supplier will not state dicyandiamide and batch date, treat the price as non-comparable.
What to Put in the Enquiry
| Field | Example |
|---|---|
| Product and CAS | Hydrogen cyanamide 50% SL, CAS 420-04-2 |
| Quantity and pack | 1 x 25 kg trial, then 200 kg drums per month |
| Assay | 50.0% min, dicyandiamide 2.0% max, pH 3.8 – 5.4 |
| End use | Industrial synthesis (or: agricultural dormancy breaking in country X) |
| Batch freshness | Dicyandiamide comfortably below limit; batch date on the COA |
| Delivery and documents | FOB or CIF, destination port, plus SDS in the required language |
Packaging and Storage on Site
- HDPE only – 25 kg cans, 200 kg drums, 1000 kg IBCs. Cyanamide solution is not a product for mild steel or galvanised containers; check the whole line, including pumps and gaskets.
- Bungs tight, out of sunlight, 5 – 30 °C. Repeated freeze-thaw is not good for the product and neither is a hot store; both push the dicyandiamide figure up.
- Rotation is mandatory. Treat this as a first-in-first-out product with a real clock on it, and keep the oldest drum at the front of the store.
- Do not heat a drum directly. If the product has crystallised in cold weather, thaw gently in a warm room or water bath at modest temperature; a band heater or open flame creates local hot spots that convert cyanamide to dicyandiamide.
- Containment: bunded storage for a toxic liquid; spill kits on site; no shared food or drink containers anywhere near it.
Acceptance Testing on Arrival
| Test | Method | Acceptance |
|---|---|---|
| Appearance | Visual against retained sample | Clear; colourless to light yellow; no haze or sediment |
| Density | Hydrometer or pycnometer at 20 °C | 1.065 – 1.095 g/mL |
| pH | pH meter on the neat solution | 3.8 – 5.4 |
| Assay | Per COA method (iodometric or titration) | 50.0% min |
| Dicyandiamide | Per COA method (HPLC) | 2.0% max, and consistent with batch age |
| Documents | Batch COA against the purchase order | Batch number, date, assay, dicyandiamide, pH, density present |
The density check is the cheapest early warning in this product: a low density with a "50%" label is either a diluted batch or a wrong COA, and both are better found before the drum is in the process.
Documents, Registration and Transport
- COA per batch and current SDS in the destination language.
- Registration status. For agricultural use, the destination market’s registration is the governing document, and it is the buyer’s responsibility. Ask us for a technical statement, not a registration number we do not hold in your country.
- Transport classification. The 50% solution ships under the UN entry and packing group stated on the current SDS – confirm the classification with your forwarder for the specific route rather than inferring it from the CAS number.
- End-use declaration. Some destinations ask for one for this product category; it is quicker to prepare at order stage than at customs.
Four Traps Worth Knowing
- Comparing on assay alone. Everything meets 50.0% min; the age shows up in dicyandiamide and pH, which is what you should be comparing.
- Buying old stock at a discount. A drum at 2.0% dicyandiamide has already lost about 2% of its active to dimer, and the remaining active degrades faster in a warm store. The discount is usually smaller than the loss.
- Mild-steel drums or lines. A cheap drum that rusts into the product costs more than the proper HDPE pack.
- Treating the 95% crystal as a drop-in substitute. It is a different product to store and to melt, and it dimerises faster – see the grade comparison guide before switching.
Frequently Asked Questions
What is the minimum order quantity?
25 kg for trial work; standard production packs are 200 kg drums and 1000 kg IBCs. The 95% crystalline grade is quoted per enquiry.
How long can I store 50% SL?
Plan in months rather than years, and keep it cool (5 – 30 °C), out of sunlight and sealed. Re-test dicyandiamide if a drum has been open or has been through a hot season.
Do you provide a registration support document?
We provide the COA, SDS and technical data needed to support a registration, but registration in the destination market remains the buyer’s responsibility and varies by country.
Can you supply in food-grade or pharma-grade packaging?
No – this is an industrial and plant-protection material. It must never be packed in food-grade containers, and dedicated HDPE packaging is used for every shipment.
References and Disclaimer
- PubChem CID 9864 – cyanamide formula (CH2N2, 42.04 g/mol) and computed properties.
- Specification limits in this guide follow the standard 50% SL commercial specification (50.0% min, dicyandiamide 2.0% max, pH 3.8 – 5.4, dilution stability 200x, density 1.065 – 1.095 g/mL).
Disclaimer: commercial and technical guidance for industrial buyers, not a specification or SDS. Handling must follow the supplier’s current SDS; agricultural use is governed by the registered label in the destination country.
PolyBlueChem supplies hydrogen cyanamide 50% SL (CAS 420-04-2) at 50.0% min, dicyandiamide 2.0% max, pH 3.8 – 5.4, in 25 kg to 1000 kg HDPE packs with per-batch COA and SDS, and quotes the 95% crystalline grade on enquiry. Send the end use, the destination and the pack size you need, and we will return a firm offer with the documents. See the 50% SL product page.