BUTTER-C
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Bemotrizinol (BEMT) sunscreen OEM/ODM manufacturing
Bemotrizinol (BEMT) Sunscreen · OEM/ODM
Bemotrizinol (BEMT; INCI name Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine) is an organic UV filter of the triazine class that absorbs across a broad range covering both UVA and UVB and is described as photostable (Teixeira Gomes et al., 2019). Annex VII of the ASEAN Cosmetic Directive lists it under its chemical name as Ref 25, with a maximum concentration of 10%. Besides filtering UV itself, in a laboratory study in an oil-in-water cream BEMT prevented avobenzone from photodegrading in a concentration-dependent way (Chatelain and Gabard, 2001) — data measured by spectrophotometry and chromatography, not on human skin, so every formula still needs its own photostability test. The molecule is large (627.8 g/mol) and highly lipophilic; on excised human skin, the filters mostly remained in the stratum corneum (Munem et al., 2021). This page differs from the general sunscreen page because BEMT is the named filter: the formula is built around dissolving BEMT so it does not recrystallize, choosing the filters that go with it and testing photostability. SPF and UVA values are labeled only once they have been measured on the finished product. Butter-C offers turnkey OEM/ODM manufacturing, from formula development and coordination of sun protection testing to labeled finished goods and the notification dossier.
Formula base
BEMT as the named filter, with enough oil phase to dissolve it
BEMT is an oil-soluble powder: the amount and type of polar oil determine whether it dissolves fully and stays dissolved in the cream; the filters that go with it determine spectral coverage. Butter-C checks the current Annex VII (version 2025-2, 12 December 2025) when building the formula.
Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine
CAS 187393-00-6; C38H49N3O5, 627.8 g/mol; computed XLogP3 10.4 (PubChem). Annex VII Ref 25 uses the chemical name "(1,3,5)-Triazine-2,4-bis-{[4-(2-ethyl-hexyloxy)-2-hydroxy]-phenyl}-6-(4-methoxyphenyl)", maximum 10%, with no specific conditions or warnings; there is no nano entry. The label uses the INCI name, not the ingredient's trade name.
Polar oil phase
Polar esters such as C12-15 Alkyl Benzoate, Dibutyl Adipate and Dicaprylyl Carbonate dissolve BEMT in the hot oil phase; without enough polar oil it can recrystallize (manufacturing practice). A photophysics study found that BEMT photodegrades less in polar media (Du et al., 2026; carried out in solvents, four of five authors from a chemical company) — not yet data on a formula.
Filters that go with it
Avobenzone (Ref 8, maximum 5%) for long UVA but photolabile on its own; Ethylhexyl Triazone (Ref 15 "octyl triazone", maximum 5%) for UVB; Diethylamino Hydroxybenzoyl Hexyl Benzoate (Ref 28, maximum 10%) for UVA. Each within its own limit; the combination is settled by photostability testing and by SPF and UVA measured on the finished product.
Oil-in-water emulsion
Glyceryl Stearate, PEG-100 Stearate and Cetearyl Alcohol with Xanthan Gum give a light cream that is easy to reapply; the Chatelain and Gabard (2001) study also used an oil-in-water cream. When the formula contains avobenzone, Disodium EDTA is added to bind metal ions, because free iron and zinc ions can cause discoloration (formulation experience).
Mineral filter (hybrid version)
Zinc Oxide (Annex VII Ref A29/A29a, maximum 25%) can be added to broaden the filter story; the whole formula is tested for photostability, as described on the zinc oxide sunscreen page.
Key technical points
Four issues specific to a BEMT sunscreen
The four items below are settled on the sample before it goes for SPF testing — changing the oils, emulsifier or filter supplier after testing can change the result.
Dissolved, not recrystallized
BEMT is fully dissolved in the hot oil phase with enough polar ester before emulsification; crystals are checked under a polarizing microscope on fresh samples, after freeze–thaw cycling and after cold storage (manufacturing practice). A recrystallized filter lowers the real-world value.
Stabilizing avobenzone: in vitro data
In an oil-in-water cream irradiated with a filtered xenon arc, BEMT prevented avobenzone photodegradation in a concentration-dependent way, and SPF and UVA ratio stayed stable after doses of up to 30 MED; with octinoxate also present, BEMT photoprotected both (Chatelain and Gabard, 2001; authors from a pharmaceutical company). The mechanism may be absorbing part of the UV or quenching the excited state (Herzog et al., 2020; authors from a chemical company). These are laboratory data — Butter-C tests photostability on the formula itself.
Skin penetration and absorption
On human skin left over from surgery (Franz cells), BEMT and other filters mostly remained in the stratum corneum, but went deeper into the epidermis at sebaceous glands (Munem et al., 2021). In an open-label maximal usage trial with a model formula containing 6% BEMT, plasma levels rarely exceeded 0.5 ng/mL, with no accumulation; the study was sponsored by the BEMT manufacturer and the abstract does not state the number of participants (D'Ruiz et al., 2023). The 0.5 ng/mL mark is an FDA procedural threshold, not a toxicity threshold.
Allergy and endocrine data
Case reports of allergic contact dermatitis to BEMT in sunscreens exist (Suzuki et al., 2022; Badaoui, 2024) — not enough to estimate frequency. In vitro and in immature rats, BEMT did not bind estrogen or androgen receptors and showed no hormone-like activity (Ashby et al., 2001; first author from an industry laboratory); there are no human data on this question.
Three formulation directions
Three filter combinations built around BEMT
BEMT – avobenzone
Avobenzone covers long UVA, BEMT filters broadly and helps avobenzone stay stable (in vitro data), with Ethylhexyl Triazone added for UVB. Avobenzone was among the three organic filters that most often caused photoallergic reactions in 1,031 people photopatch-tested for suspected photoallergy (European multicentre study, 2012) — noted in the safety file.
BEMT without avobenzone
BEMT combined with Diethylamino Hydroxybenzoyl Hexyl Benzoate (UVA) and Ethylhexyl Triazone (UVB). For brands that want to avoid avobenzone; photostability is still tested and UVA measured on the finished product, not inferred from the ingredient list.
Hybrid BEMT – zinc oxide
Zinc oxide is added to lower the total organic filter load; zinc oxide makes the cream whiter and does not tolerate an acidic base. A photostability test of the whole formula is required; not labeled "mineral filters only".
Packaging is planned with the formula
Multilayer plastic tubes or pump bottles, light-protective; filters and esters can swell some plastics, so compatibility is tested. This product is a cream or lotion, not a spray.
Parameters we monitor
What our R&D team measures on every sample
Below are the parameters Butter-C monitors during formula development and scale-up to production. Specific limits are agreed with you on the approved sample and then written into the product's in-house specification.
- SPF
- The labeled value is measured on people under ISO 24444:2019 at a laboratory whose ISO/IEC 17025 accreditation covers this method; in vitro screening results are used only during formula development.
- UVA protection
- Measured under ISO 24443:2021 (UVA protection factor, critical wavelength); the UVA symbol on the label follows the rules of the target market, since the ASEAN sunscreen labeling guideline does not set a specific symbol.
- Water resistance
- Tested under ISO 16217:2020 when the label says "water resistant".
- Photostability
- Each filter quantified (chromatography) and the formula's UV absorbance measured before and after UV exposure; repeated whenever the filter combination changes.
- Filter content
- BEMT and the accompanying filters quantified in the finished product by the testing laboratory's method; each within its own Annex VII limit.
- Crystallization and emulsion stability
- Centrifugation, freeze–thaw cycling, storage at 40 °C and cold storage; crystals checked under a polarizing microscope, monitoring for separation and color change.
- Skin feel
- Spreadability, shine, pilling when layered, eye sting when applied near the eye area.
- Microbiology & preservative challenge
- Tested at a GLP / ISO 17025-accredited laboratory; preservative efficacy test under ISO 11930.
Claims
Writing claims within the cosmetic scope
Every number on a sunscreen label must be backed by a test report on the finished product itself in the Product Information File. Wording follows the ASEAN sunscreen labeling guideline (Appendix X, Revision 02, 18 November 2025); whether this guideline is mandatory needs regulatory confirmation, and Butter-C applies it as a minimum. Butter-C reviews the wording on the label and in marketing materials when preparing the notification dossier.
Helps protect skin against UVB; "broad spectrum" and "UVA protection" only once UVA has been measured on the finished product
Instead of: blocks UV completely, total sun protection, "sunblock".
SPF and PA according to the test result; SPF above 50 labeled "SPF 50+"
Instead of: values calculated from the ingredient list, SPF 80 or SPF 100.
"Photostable formula" — only with photostability results on the finished product
Instead of: stays effective all day in the sun, claims inferred from in vitro data on the ingredient.
Directions to apply enough and reapply after sweating, swimming or toweling
Instead of: all-day protection, no need to reapply.
Mandatory label warning
"Do not stay too long in the sun, even while using a sunscreen product" (Annex VII, for primary sunscreen products) — printed in the equivalent Vietnamese, with the translation approved by regulatory affairs.
Try on a small area of skin first; anyone who has reacted to sunscreens should ask a dermatologist; pregnant women should ask a doctor
Instead of: non-irritating, does not enter the skin, completely safe for children and pregnant women. The product is not positioned for children.
Bemotrizinol (BEMT) filter named by its INCI name
Instead of: "FDA-approved" for a cosmetic sold in Vietnam, "reef-safe" without data, the ingredient's trade name, prevents skin cancer.
Manufacturing specifications
Current capabilities
- Texture
- Sunscreen cream, lotion or gel-cream, untinted or with a light tone-up.
- Pack formats
- Tubes, pump bottles. Volume agreed when packaging is selected.
- Minimum order quantity
- Agreed per order — depends on the formula direction and the pack format chosen.
- Testing
- Quality parameters tested at a GLP / ISO 17025-accredited laboratory; SPF and UVA measured at a specialized testing facility.
- Dossier
- Product Information File (PIF) with SPF, UVA and photostability reports and the COA of each filter; notification dossier prepared by Butter-C.
- Packaging
- Label design with the mandatory sunscreen warning and reapplication directions; printing and packing run in parallel with formula work.
Suggested product concept
Light BEMT – avobenzone face sunscreen
A product concept to help you picture the possibilities, not a ready-made product for sale. The actual formula is developed to match your brand positioning and price range.
BEMT as the named filter
Broad-spectrum filter; the level is set by SPF, UVA and photostability testing, never above 10%.
Avobenzone and ethylhexyl triazone
Add long UVA and UVB, each within its own Annex VII limit (5% and 5%).
Oil-in-water emulsion
Polar esters dissolve the filters; a thin, dry-touch texture; fragrance-free.
50 ml tube
The label carries the mandatory sunscreen warning and directions to apply enough and reapply.
Customization options
What you can specify
The same product type can serve very different customer groups depending on the brand. Tell us your requirements in the areas below and our team of pharmacists will develop a matching formula.
Target values
Desired SPF and UVA level — the final number follows the test result on the finished product.
With or without avobenzone
With avobenzone: long UVA coverage, photostability testing needed; without avobenzone: a different UVA filter combination.
Organic-only or hybrid
Organic-only for a clear texture with little white cast; hybrid with added zinc oxide.
Texture and finish
Cream, lotion or gel-cream; matte dry-touch or dewy finish.
Tone-up
Untinted or a light tone-up with pigments — each version is a separate test.
Target market
Domestic only or export. In the US, sunscreens are over-the-counter drugs: the FDA added bemotrizinol up to 6% (order OTC000039, issued 10 June 2026) with its own dosage-form conditions — the 6% figure does not apply to cosmetics sold in Vietnam, where the reference is 10% under Annex VII.
Further reading
Related topics
Bemotrizinol (BEMT) in cosmetics
Photostability, stabilizing avobenzone, skin penetration data, the ASEAN limit and the new US rules (in Vietnamese).
Facial sunscreen manufacturing
The three filter systems — organic, inorganic and hybrid — for sunscreens in general.
Avobenzone in cosmetics
The long-UVA filter often paired with BEMT and why it needs photostabilizing (in Vietnamese).
SPF: what it means and how it is tested
ISO methods and the ASEAN sunscreen labeling guideline (in Vietnamese).
Using sunscreen correctly
How much to apply, when to reapply and label wording not to trust (in Vietnamese).
How we work
From idea to finished batch
Eight steps and three milestones signed off by both sides: approved sample, notification number, finished batch. Step-by-step details →
Get started
Tell us about the product you plan to launch
Send us your product direction and expected volume. Our team will get back to you during business hours (Vietnam time, GMT+7).
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