Start from the market, then pick the particle size. All three series behave the same in the formula — they differ only in how much soluble boron the powder can release.
Kingbornit 7000 (7006 / 7012 / 7015 / 7020) is held to soluble borate ≤0.02%, which is 200 ppm, and is the usual choice for the EU and US. Kingbornit 9000 (9006 / 9011 / 9015 / 9020) is specified to boron leaching ≤20 ppm — ten times tighter — and is the series we normally ship against Japanese requirements. Kingbornit 3000 (3002 / 500 / 3012 / 3015 / 3020) sits at ≤0.06%, with 3002 at ≤0.1%.
All three series share the same 6–20 µm size ladder and the same specific surface area at each size, so changing series does not change the skin feel. If your target market is still open, 7000 covers the widest range of customer questionnaires.
Choose by the skin feel you are targeting, then check the coverage requirement.
6 µm (7006, surface area 9) has the highest surface area in the range and gives the most pronounced soft-focus and coverage, but slip is weaker and it is more prone to agglomeration. 12 µm (7012, surface area 4) is the balance point most pressed and loose powders are built around. 15 and 20 µm (7015, 7020, surface area 3 and 2) give the most slip and the easiest spreading, at the cost of soft-focus.
A practical rule: loose powder and blush tend toward 12–15 µm, pressed eyeshadow toward 15–20 µm where glide matters more than coverage, and products where you want pore blurring toward 6 µm.
A common starting point is 3–8%, adjusted upward for skin feel. Loadings above 15% are rare.
At low loading boron nitride mainly improves spreading and slip, and contributes little to compact strength. From roughly 5% the difference in hand feel becomes noticeable. Loose powders can go to 8–10%. Beyond that you are buying smaller and smaller improvements at a rising cost, and a high proportion of platy powder makes the pressed compact more brittle, so it chips more in transit.
If you are reformulating away from talc, the loading usually lands higher — see the replacement question below.
Partly, and not one-for-one. Replacing 20–50% of the talc is usually workable in pressed and loose powders; full replacement is not.
The slip and skin feel are better than talc and the platy structure is similar, so the texture translates well in that range. Three things stop you going further. Oil absorption is different — talc absorbs in the 40–81 range while boron nitride absorbs very little, so oil control drops if you swap everything. Cost per kilo is several times higher. And compact strength depends on the talc fraction, so a full swap needs a binder or pressing review.
In practice, pair the substitution with a higher oil-absorbing filler rather than replacing talc with boron nitride alone.
It is the fraction of boron that can leach out of the powder, and it is what market-specific questionnaires ask about — not the total boron content.
Boron nitride itself is chemically inert. Residual soluble borate comes from the manufacturing route, so it is controlled by grade rather than by the customer's formula. That is the whole reason the range is split into 7000 / 9000 / 3000 instead of being one series with different particle sizes.
When a customer sends a regulatory questionnaire, the answer comes from the batch COA, which reports the figure for that lot. Ask for the COA of the lot you are buying, not a generic series datasheet.
Yes, and it is the main reason size selection matters more than series selection.
Surface area drives how much binder and oil the powder takes up, and how much light it scatters. Going from 6 µm (area 9) to 20 µm (area 2) cuts the surface area by more than four times at the same loading. In practice that means less oil demand, easier wetting, better flow — and visibly less soft-focus, because larger plates scatter less.
If a formula was built around 6 µm and you move to 20 µm to save cost, expect the texture to feel lighter and the coverage to drop. Compensate with a finer soft-focus filler rather than by increasing the boron nitride loading.
Yes, but for a different reason than in powders. In liquids it is a texture and slip modifier, not a structure former.
The plates orient during application and reduce the drag you get from high oil-absorption fillers, which is why foundations containing it spread more evenly and feel less dry. Typical use is 1–5%. Above that, the low oil absorption starts to work against you in an emulsion, and you may see viscosity drop or a slight gloss increase.
In lip products it is used at low levels for glide and to reduce the waxy drag of the base. Because it is inert and has no colour of its own, it does not shift the shade.
Every lot ships with a COA reporting the specification figures for that batch, including the soluble boron figure for that grade — quoted as soluble borate % on the 7000 and 3000 series and as boron leaching ppm on the 9000 series. TDS and SDS are available per grade.
For questionnaires we can support with the composition and CAS information, the specification limits, and the soluble boron figure per lot. What we do not do is issue a REACH registration statement on the customer's behalf — whether a substance needs registering depends on your tonnage and role in the supply chain, and that determination is yours or your OR's to make.
If you tell us the destination market and the exact wording your customer needs, we can tell you which of those we can answer directly and which you will need to resolve locally.
Standard grades are normally stocked and ship in small quantities for sampling; production volumes are quoted per order. Lead time depends on grade and quantity rather than being fixed.
In practice: sample quantities go out first so you can run the formula before committing, and the commercial quote follows the sample result. If you are scheduling a launch, tell us the target date with the sample request — the grades that need a production run are the ones where timing slips, and it is cheaper to plan that at the start than to expedite later.
Exact MOQ, packing and shipping terms are quoted against the specific grade and destination.
It does not add coverage, and it is not a whitening filler. Its refractive index is close enough to typical binder and filler systems that it scatters little.
What it does is make the finish look softer: the plates lie flat on the skin, which evens out how light scatters and lowers the visible contrast of pores and small imperfections. That is optical blurring, not hiding. If you need coverage, that has to come from titanium dioxide or an equivalent.
One practical consequence: in a high-coverage formula, adding boron nitride will not lighten the shade, but it can make the finish look slightly less flat, which some briefs describe as a loss of coverage. It is a change in appearance, not in pigment loading.
We reply within one business day with shipping arrangements and technical documents. Samples are free of charge; freight is collect or credited against your next order.
