Short answer. A CoA reports measured results for one delivered batch, while the TDS gives the typical limits for a grade. Check four things first: the assay basis (w/w for Technical grade, v/v for IP grade), the benzene units (mg/kg or ppm), the water result, and the density temperature, against SPC-TDS-ALC-001 or SPC-TDS-ALC-006.
CoA versus TDS versus SDS: three different documents
Buyers often use the words interchangeably, but each document answers a different question.
- TDS (technical data sheet): the typical specification limits for a grade. It tells you what a conforming batch should look like.
- CoA (Certificate of Analysis): the measured results for a particular batch. It tells you what you actually received.
- SDS (safety data sheet): hazards, handling, storage and transport. It does not state quality limits.
Supreme Petro Chemicals is a trader and importer, not a manufacturer. A batch Certificate of Analysis is supplied with every delivery. Our TDS files name the makers: Deepak Fertilisers and Petrochemicals Corporation Ltd and Deepak Phenolics Ltd for Technical grade, and Deepak Phenolics Ltd for IP grade.
Step 1: check the identity lines first
Before reading any number, confirm the paperwork matches the consignment:
- Product name and CAS number: isopropyl alcohol, CAS 67-63-0 (not n-propanol, CAS 71-23-8).
- Grade named on the CoA: Technical or IP.
- Batch number and date: the same batch number printed on the drum, IBC or tanker documents.
- General knowledge: a CoA normally carries a signature or stamp of the issuing quality department; if it is missing, ask.
A CoA for the wrong grade or a different batch number is the first red flag, and is worth raising before the material is used.
Step 2: assay, and the basis it is stated on
Technical grade is specified at 99.80% w/w minimum by gas chromatography (GC). IP grade is specified at 99.0% v/v minimum. These are different bases, so do not set them side by side and conclude one is purer. Check that the CoA states the unit and method, and compare it with the matching TDS only. If a CoA gives a bare percentage with no basis, ask for the basis.
Step 3: the parameter checklist
The table lists what each line means and what to look for. Limits are those printed on the TDS; your batch result should sit inside them. Some Technical-grade limits are quoted by one maker only on the TDS, and the table says which.
| Parameter | Technical limit | IP limit | What to check |
|---|---|---|---|
| Assay | 99.80% w/w min (GC) | 99.0% v/v min | Basis and method stated; result at or above the minimum. |
| Water | 0.10% w/w max | 0.50% max | Matters for water-sensitive coatings, inks and cleaning. |
| Benzene | 2 mg/kg max (Deepak Phenolics basis) | 2 ppm max | Units as printed; see below. |
| Non-volatile residue | 0.005% w/v max | 20 ppm max | Matters for residue-free cleaning. |
| Colour | 5 APHA max (Deepak Phenolics basis) | Not listed | Technical only. |
| Aldehydes and ketones | 0.20% max (Deepak Phenolics basis) | Not listed | Technical only. |
| Refractive index at 20 C | 1.376 to 1.378 (DFPCL basis) | 1.376 to 1.379 | Quick identity cross-check. |
| Peroxides | Not listed | Nil | IP only. |
| Impurities (ex 2-butanol) | Not listed | 0.30% max | IP only. |
| Absorbance at 230 nm | Not listed | 0.30 max | IP only. |
Source: SPC TDS SPC-TDS-ALC-001 (Technical) and SPC-TDS-ALC-006 (IP); maker basis shown where the TDS names one.
Benzene: mg/kg and ppm
The Technical-grade TDS states benzene as 2 mg/kg maximum, and the IP-grade TDS states it as 2 ppm maximum. As general knowledge, one milligram per kilogram is one part per million by mass, so the two limits are the same size, but the labelling differs. When you compare CoAs, make sure the unit and method are stated and that the figure is a measured value rather than a bare < sign with no detection limit.
Density and the temperature behind it
Density is the line most often compared wrongly because the maker and temperature change the number. On the Technical-grade TDS, one maker (DFPCL) states specific gravity as 0.783 to 0.787 at 25 C, and the other (Deepak Phenolics) states relative density as 0.7850 to 0.7870 at 20 C. IP grade is 0.785 to 0.789. The ranges overlap, but the conditions are different: always read the temperature before judging a result as in or out of range.
Acidity: two makers, two bases
Acidity on the Technical-grade TDS appears twice. DFPCL expresses it as the volume of 0.1 N NaOH needed to neutralise (0.700 ml maximum), while Deepak Phenolics expresses it in mg/kg (20 maximum). These cannot be converted without the method detail, so match your CoA to the maker's own line rather than to the other maker's number.
A short per-batch checklist
- Product, CAS and grade on the CoA match the order.
- Batch number matches the container labels.
- Assay basis (w/w or v/v) and method are printed, and the result meets the minimum.
- Water, benzene, non-volatile residue and, for IP, peroxides are within limits and in the right units.
- Density or specific gravity is read at the temperature stated.
- Keep the CoA with your goods-received record.
What a CoA does not tell you
A CoA does not make a grade suitable for your end use. Technical grade is not a pharmacopoeial, food or pharma grade, and BP limits are available on request only. If your process is regulated, your QA team decides whether the grade and the CoA are acceptable. The CoA also does not replace the SDS: IPA is a highly flammable liquid with a flash point of 12 C, and the handling rules are in the SDS.
Where to find the documents
The Technical-grade TDS, IP-grade TDS and SDS are available from the isopropyl alcohol product page. For how strength and units work before you order, see the IPA concentration guide.
To request IPA, send the grade, quantity, pack and location on +91 86087 80096. We quote within 4 working hours, and a batch Certificate of Analysis is supplied with every delivery.