A paraffin wax certificate of analysis lists batch-specific test results — melting point (ASTM D87), oil content (ASTM D721), congealing point (ASTM D938) and Saybolt color — each tied to a published standard method. Reading it means matching every figure to its method and checking it against your own specification before accepting the batch. BHD Group supplies paraffin wax, petroleum jelly and slack wax across its waxes family, backed by documentation traceable to named standards.
A paraffin wax certificate of analysis records the test results a specific wax batch produced — melting point, oil content, congealing point, color and carbon-number distribution. Reading it means matching each figure against the standard method that produced it, then checking that figure against your own specification. This guide is a paraffin wax certificate of analysis how to read overview for buyers who receive a COA and need to sign off a batch with confidence.
Who this guide is for
This is written for three buyers who see a wax COA before anyone else does. Candle and wax formulators check melting point and oil content before a pour run. Cosmetics and personal-care buyers check oil content and color before a cream or balm batch starts. Procurement and quality staff at distributors check the whole document before releasing payment. If you sign off shipments, this article is for you.
What is a certificate of analysis, in plain terms?
A certificate of analysis (COA) is a lab report issued with a wax shipment. It lists the properties measured on that specific batch, the test method used for each, and the result. It is not a specification sheet — a spec states the target range; a COA states what this lot actually measured. A buyer reads the COA against the agreed spec to confirm the batch is acceptable.
How does a paraffin wax COA work, line by line?
Each line on the COA pairs a property with a standard test method and a numeric result. Below is a reference table drawn from the published standards a wax lab typically cites.
| Standard | What it measures | Why a buyer checks it |
|---|---|---|
| ASTM D87 | Melting point, by cooling curve | Confirms the wax sets and softens in the temperature range your process needs; especially relevant for highly paraffinic or crystalline waxes (ASTM International, undated) |
| ASTM D721 | Oil content | Oil content changes strength, hardness, flexibility, scuff resistance, friction and melting behavior, so it is checked whenever the batch must hold shape or finish (ASTM International, 2017) |
| ASTM D938 | Congealing point | Shows the temperature where the cooling wax develops resistance to flow, which tells a formulator when a pour or coat will set (ASTM International, 2025) |
| ASTM D612 | Carbonizable substances | Screens for impurities that darken or degrade the wax under heat (ASTM International, 2017) |
| EWF Method 001/03 | Carbon number distribution, C16–C100 | Gives the hydrocarbon profile of the wax by gas chromatography, useful when comparing lots or sources (European Wax Federation, 2015) |
Melting point and congealing point: what the difference tells you
Melting point (ASTM D87) and congealing point (ASTM D938) are measured differently and answer different questions. Melting point tracks a cooling curve to find where the wax changes phase; it is the test most wax suppliers and buyers reach for on highly paraffinic waxes (ASTM International, undated). Congealing point identifies the temperature where the cooling wax first sets or resists flow — useful for petrolatum as well as paraffin wax (ASTM International, 2025). A COA that reports only one of the two is still useful, but knowing which one you are reading avoids a mismatched comparison across suppliers.
Oil content: the paraffin wax COA oil content line
The paraffin wax COA oil content line follows ASTM D721, which applies to waxes with a congealing point of 30°C or higher and no more than 15% oil (ASTM International, 2017). Oil content is not a minor footnote. It shifts hardness, flexibility, scuff resistance, and how the wax strains and melts in service (ASTM International, 2017). A candle maker targeting a firm container pour, or a cosmetics buyer blending a balm base, should treat this line as a primary acceptance criterion, not a secondary check.
Color and Saybolt number: the wax Saybolt colour specification
Refined paraffin wax analysis commonly includes a Saybolt color number alongside melting point, oil content, odor, penetration and density (Intertek, undated). The wax Saybolt colour specification is a visual clarity measure, read on a defined scale rather than a percentage. For candle applications where buyers search White, Snow White or Super Snow White tiers, or specify grades such as HP3, M3 or UL2, the Saybolt line is one of the first numbers checked against the target tier.
Application-specific reading: what to check for your use
Container, economy and utility candles
The waxes family is used to make pillar candles (client-published evidence). For container, economy and utility candle work, and for grave, church or mourning candle lines, the melting point and Saybolt color lines matter most: they determine set behavior in the mold and visual clarity in the finished piece. Buyers doing slack-wax blending or textile-yarn paraffin work should also confirm oil content, since blended and technical-grade waxes carry oil levels that a pure candle wax would not.
Cosmetics and personal-care blends
The waxes family is used to make cosmetic creams and balms (client-published evidence). Here, oil content (ASTM D721) and congealing point (ASTM D938) both matter — oil content affects texture and stability, and congealing point affects how the blend sets during compounding. A cosmetics buyer reading a COA should treat these two lines as inseparable, not check either in isolation.
What to check before you order
- Confirm the COA states the test method (ASTM, ISO or EWF number) next to every result, not just a bare figure.
- Match the melting point or congealing point method to your process — cooling-curve melting point for highly paraffinic wax, congealing point where a set-point matters.
- Check the oil content line against ASTM D721 and against your own hardness and finish requirements.
- Verify the Saybolt color number against the tier you specified — White, Snow White or Super Snow White.
- Ask which subcommittee or standard body issued the referenced method, so you can trace it if a result is disputed.
- For blended or technical wax, confirm whether the batch was tested as pure paraffin or as a slack-wax blend, since method suitability differs.
- Request the batch or lot number on the COA and confirm it matches the shipment.
- Keep the COA on file against the purchase order — it is your evidence record if a downstream batch fails.
Why this matters: standards bodies behind the numbers
ASTM Subcommittee D02.10 holds jurisdiction over petroleum wax property standards, with 15 active matching standards including D721 for oil content (ASTM International, undated). This is why a COA that cites an ASTM number is checkable — the method is published and maintained, not a supplier's private test. ISO 3841:1977, the older melting-point-by-cooling-curve method, has since been withdrawn and was never suitable for microcrystalline wax or blends with paraffin or scale wax (ISO, 1977) — a useful check if an older COA cites it. In the United States, petroleum wax intended for food contact also carries ultraviolet absorbance limits under 21 CFR 178.3710, tested per the procedure in 21 CFR 172.886 (U.S. eCFR, undated).
Working with BHD Group
BHD Group supplies paraffin wax, petroleum jelly and slack wax as headline goods within its waxes family, alongside bitumen, carbon black, polymers, rubber process oils and the wider industrial chemicals range, across two divisions — BHD Chemical and BHD Sourcing — one accountable house behind both. This paraffin wax certificate of analysis how to read guide reflects how our own documentation is built: every batch figure traceable to a named method, on spec and on time. Buyers evaluating a paraffin wax certificate of analysis how to read explained walkthrough against their own procurement checklist are welcome to send us a spec and ask what a matching COA looks like.
Sources
- ASTM International (undated) — ASTM D87 Standard Test Method for Melting Point of Petroleum Wax (Cooling Curve), https://store.astm.org/d0087-09r18.html
- ASTM International (2017) — ASTM D721-17 Standard Test Method for Oil Content of Petroleum Waxes, https://store.astm.org/d0721-17.html
- ASTM International (2025) — ASTM D938-25 Standard Test Method for Congealing Point of Petroleum Waxes, Including Petrolatum, https://store.astm.org/d0938-25.html
- ASTM International (2017) — ASTM D612-88(2017) Standard Test Method for Carbonizable Substances in Paraffin Wax, https://www.astm.org/d0612-88r17.html
- ASTM International (undated) — Subcommittee D02.10 on Properties of Petroleum Waxes and Alternative Wax-like Materials, https://www.astm.org/membership-participation/technical-committees/committee-d02/subcommittee-d02/jurisdiction-d0210
- European Wax Federation (2015) — EWF Method 001/03, Standard Test Method for Analysis of Hydrocarbon Waxes by Gas Chromatography, https://www.wax.org/uploads/test-methods/EWF_Analysis_Hydrocarbon_Waxes-2015.pdf
- U.S. Electronic Code of Federal Regulations (undated) — 21 CFR 172.886, Petroleum wax, https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-172/subpart-I/section-172.886
- U.S. Electronic Code of Federal Regulations (undated) — 21 CFR 178.3710, Petroleum wax, https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-178/subpart-D/section-178.3710
- ISO (1977) — ISO 3841:1977, Petroleum waxes — Determination of melting point (cooling curve), https://www.iso.org/standard/9403.html
- Intertek (undated) — Paraffin Wax Testing, https://www.intertek.com/chemicals/paraffin-wax/
Frequently asked questions
What is paraffin wax certificate of analysis how to read?
It is the practice of matching each line on a wax COA — melting point, oil content, congealing point, color — to the standard test method that produced it, then checking the result against your own specification before accepting a batch.
How does paraffin wax certificate of analysis how to read work?
Start with the method cited on each line (for example ASTM D87 for melting point or ASTM D721 for oil content), confirm the batch or lot number matches your shipment, then compare each result to your agreed spec rather than reading the figures in isolation.
Who is paraffin wax certificate of analysis how to read for?
Candle and wax formulators checking melting point and oil content before a pour, cosmetics and personal-care buyers checking oil content and color before a cream or balm batch, and procurement or quality staff releasing payment on a shipment.
What are the benefits of paraffin wax certificate of analysis how to read?
It lets a buyer catch a mismatched batch before it enters production, gives a traceable record for disputes, and confirms that a supplier's figures rest on published, checkable standards such as ASTM and EWF methods rather than private testing.
Why buyers work with BHD Group
Two divisions operate under a single accountable house. There is no handoff between a trading desk and a sourcing desk that leaves a buyer chasing an answer — one team owns the order from enquiry to delivery.
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