Few raw materials cross so many industries as quietly as white mineral oil (liquid paraffin, INCI Paraffinum Liquidum). It is the carrier in baby oil, the glazing agent on confectionery, the release oil in bakery plants, the spinning-oil base for synthetic fiber, and the plasticizer in white sidewall rubber. Yet buyers get into trouble with it constantly — not because the chemistry is difficult, but because a #22 cosmetic oil, a #22 food oil and a #22 industrial oil are three different products that happen to flow the same. This guide walks through how viscosity numbers map to applications, how the three grades differ, and what to demand on the COA.
What the N-number means
The number in White Mineral Oil 22# is the kinematic viscosity at 40 °C in mm²/s (cSt), per the Chinese industrial convention. So 5# flows at roughly 5 cSt (thinner than water is a myth — but close to a light silicone), while 70# is a distinctly viscous, slow-draining oil. The number is your first and best purchasing filter: within one application family, formulators standardize on a viscosity band and rarely deviate. What the number does not tell you is purity — that is the grade, and this is where spec sheets diverge.
Three grades, two CAS numbers
- Cosmetic grade — CAS 8012-95-1, refined to USP/NF or JP-equivalent limits: color water-white, UV absorbance tightly limited (typically ≤ 0.1–0.3% in the 260–420 nm window, the regulatory proxy for polynuclear aromatics), heavy metals and sulfated ash near zero. Intended for leave-on and rinse-off skin care, hair care and color cosmetics.
- Food grade — also CAS 8012-95-1, made to FDA 21 CFR 172.878 or equivalent (GB 4853 in China): the same deep hydrotreating as cosmetic oil plus food-contact documentation. Used as a release agent, glazing and coating agent, dust suppressant for grain, and lubricant with incidental food contact.
- Industrial (technical) grade — CAS 8042-47-5. Refined for color, volatility and oxidation stability, but without the UV-absorbance and pharmacopoeia impurity guarantees. Never acceptable for skin-contact or food-contact formulations; completely appropriate for textiles, rubber, plastics, candles, inks and general lubrication.
The commercial trap runs in both directions: paying cosmetic-oil prices for a candle plant is money burned, and — far worse — qualifying an industrial oil into a cream or a bakery line is a compliance failure waiting for an audit. Confirm the CAS number and the grade on the COA before sampling.
Viscosity selection by application
| Viscosity grade | Cosmetic use | Food / industrial use |
|---|---|---|
| 5–10# | Makeup removers, baby oils, hair serums, bath oils — fast spreading, light after-feel | Food: sprayable release oil; Industrial: low-viscosity spinning and machine oils |
| 15–26# | Cleansing milks, lotions, sun care emulsions — the workhorse band for emulsified systems | Food: bakery pan oil, grain dust control; Industrial: textile coning oils, PS/extender |
| 32–36# | Creams, pomades, petrolatum-type anhydrous systems — more occlusion, more slip | Food: confectionery glazing; Industrial: rubber processing, candle and ink bases |
| 70–100# | Rare in skin care; occasionally in hair waxes and barrier balms | Industrial: high-load rubber extender (white goods), general machinery lubrication |
Two formulation notes worth more than the table: first, viscosity predicts feel but not spread — a 5# oil still needs an ester co-emollient (or isododecane-type volatile) if the brief is "vanishes into skin". Second, in emulsions white mineral oil raises viscosity with loading but contributes no stability; the emulsifier system carries that burden, so pilot with your actual wax/emulsifier package, not at a single point.
COA specs that separate good oil from cheap oil
- Kinematic viscosity at 40 °C — should sit in a narrow band around the stated grade (typically ±10%); wide bands signal blended lots and batch-to-batch drift in feel.
- UV absorbance (260–420 nm) — the single most telling number. Cosmetic/food oil must be ≤ 0.1–0.3% across the window; industrial oil is not tested to this limit. If a "food grade" COA lacks this line, treat the grade claim as unproven.
- Color — Saybolt +25 to +30 (water-white) for cosmetic/food; industrial commonly ≥ +20. Darkening on aging suggests insufficient hydrotreating.
- Flash point & volatility — open-cup flash point scales with viscosity (roughly 150–160 °C at 10# up to 220 °C+ at 70#). Low flash on a high-number oil means light-end contamination — the cause of "sweating" and odor in finished goods.
- Carbon-type composition & pour point — paraffinic vs naphthenic character changes low-temperature clarity; pour point (typically −15 to −30 °C) matters for cold-climate shipping and winter cosmetics.
- Heavy metals, sulfated ash, sulfur — cosmetic/food: lead ≤ 1 ppm, arsenic ≤ 1 ppm, ash ≤ 0.005–0.01%, sulfur effectively nil. These are hygiene fingerprints of the hydrogenation train, not routine additives.
Sampling and procurement practice
Because white mineral oil is a commodity with wide quality spread, the practical workflow is: shortlist by CAS number and grade claim (8012-95-1 for cosmetic/food, 8042-47-5 for industrial), reject any COA missing UV absorbance or flash point, then run a feel/flow pilot against your incumbent oil at the same viscosity number. Ask for per-lot COAs, not a one-time spec sheet — viscosity and color drift are the first signs of a supplier blending grades. For food and cosmetic use, also confirm the oil is produced under the relevant registration (GB 4853 / 21 CFR 172.878 documentation for food; INCI and safety dossier support for cosmetics).
Shanghai Better Chemical supplies the full white mineral oil ladder — cosmetic grades 5#, 7#, 10#, 15#, 22#, 26#, 32# and 36#; food grades including 22# and 70#; and industrial grades from 22# through 46# — with COA/TDS/MSDS, per-lot viscosity and color data, and food-grade compliance documentation. Tell us your application and target viscosity, and we will recommend the grade and quote current pricing.