A preservative is not a fragrance or a “natural” claim. It is the chemistry that keeps water-rich personal care formulas from growing bacteria. Esteem’s preservative table is four INCI grades with different chassis. Specify the product type, then the ligand—not one bottle for every SKU.
What the Preservative Table Is For
Dermatological creams, sunscreens, face washes, liquid soaps, and sanitizers all contain water. They need an antimicrobial program matched to pH, surfactant, and packaging. Esteem publishes four grades. This guide maps them. It is not a substitute for a Pharmacopoeia challenge test or for a finished-goods preservative blend with a claimed kill spectrum.
Esteem Grades by Chassis
| INCI (as listed) | Role on the table | Start here when |
|---|---|---|
| Phenoxyethanol | Bactericide; often with quats | Hair creams, sunscreens, face lotions |
| Phenoxypropanol | Bactericide; often with quats | Hair creams, sunscreens, face washes |
| Benzyl Kohnium Chloride (80/50) | Quat preservative; emolliency/substantivity | Topical and ocular cosmetics/pharma |
| Ethyl hexyl Imino Dipropronate | Preservative and biocide | Liquid soaps, hand wash, sanitizers |
Match Chassis to the Published Job
| Product type | Start with (as listed) | Do not assume |
|---|---|---|
| Hair cream, sunscreen, face lotion | Phenoxyethanol (often with a quat) | A sanitizer biocide will protect a cream |
| Hair cream, sunscreen, face wash | Phenoxypropanol (often with a quat) | 1:1 swap with phenoxyethanol by INCI stem |
| Topical or ocular cosmetic/pharma | Benzyl Kohnium Chloride (80/50) | Compatibility with a high-anionic shampoo |
| Liquid soap, hand wash, sanitizer | Ethyl hexyl Imino Dipropronate | Use as a default leave-on cream preservative |
Phenoxyethanol vs Phenoxypropanol
Phenoxyethanol is listed for dermatological products such as hair creams, sunscreens, and other face lotions. The table calls it an excellent bactericide used in combination with quaternary ammonium compounds in cosmetic and pharma formulas as a preservative. Phenoxypropanol carries the same bactericide-plus-quat language; the application line is hair creams, sunscreens, and other face washes. That is a system, not a solo hero. Phenoxyethanol is the common leave-on workhorse; phenoxypropanol is the propanol analogue on the same table. Challenge-test the finished chassis—do not swap 1:1 by INCI name alone.
Leave-on creams (lotions, sunscreens, hair creams) fail preservation for different reasons than rinse-off washes: water activity, oil load, packaging headspace, and consumer dip-in jars. A phenoxy grade that passes in a pump lotion can fail in a wide-mouth jar. Share packaging with the sample request.
Benzyl Kohnium Chloride (80/50)
The published name on the table is Benzyl Kohnium Chloride (80/50). It is listed for dermatological products such as hair creams, sunscreens, and other face washes, as a preservative in various topical and ocular products in cosmetics and pharma. It also enhances emolliency and substantivity. The 80/50 notation is the listed concentration pair—request the cut you need; do not assume one assay. Quats can clash with anionics and some fragrance oils. Check compatibility before you dose into an SLES or sulfosuccinate shampoo. Precipitation is a formula failure, not proof that you need “more preservative.”
Ocular and topical pharma rules are stricter than a rinse-off cosmetic. If those rules apply, say so on the brief. Emolliency/substantivity can be useful in a cream and unwanted in a clear gel that must stay water-white.
Ethyl hexyl Imino Dipropronate for Washes and Sanitizers
Ethyl hexyl Imino Dipropronate is listed for liquid soaps, hand wash, and sanitizers as a preservative and as a biocide in personal care products and sanitizers. That is a rinse-off and sanitizer chassis, not a default cream preservative. Do not drop it into a sunscreen emulsion because the sanitizer line exists. Specify pH, anionic load, and whether the brief is soap or alcohol sanitizer. Soap (including potassium cocoate 40%) and alcohol sanitizers are different microbial and solubility problems.
Keep rinse-off biocide and leave-on phenoxy/quat as separate trials from the preservatives table. High water, humectants, and mild anionics all change microbial risk. Pair preservation with humectants and a defined cleanser base such as detergent bases. Do not hide a failed challenge test by adding more fragrance.
Challenge Tests, Not a Universal Cocktail
The table describes single INCI grades. Many cosmetics use combinations (phenoxyethanol plus quat, or a sanitizer biocide plus a surfactant). Esteem does not publish a “universal cocktail” dose or a claimed kill spectrum on this page. Request named grades, share formula type, then challenge-test the finished formula. Do not scale a jar test to a 200 kg batch without a repeat. Related chassis: mild detergent bases, emollients, sunscreen emulsifiers.
Request order from the four published jobs: Phenoxyethanol for hair creams, sunscreens, and face lotions when a bactericide-plus-quat system is acceptable; Phenoxypropanol when the same table job is written against face washes as well as creams and sunscreens; Benzyl Kohnium Chloride (80/50) when the brief is topical or ocular and you have already checked anionic compatibility; Ethyl hexyl Imino Dipropronate when the SKU is liquid soap, hand wash, or sanitizer. State pH, packaging, and whether pharma topical rules apply. A pass in a beaker is not a pass in the pack.
Phenoxyethanol plus a quat is a combination the table already describes; it is still not a licensed “complete system” with a published dose. Phenoxypropanol is not a drop-in if the solvent, odor, or wash-off profile of the analogue matters to the chassis. BKC (80/50) can add substantivity that a rinse-off shampoo does not want. Iminodipropionate belongs on soap and sanitizer briefs; putting it into a leave-on lotion because “it is a preservative” ignores the published application line. Challenge-test bacteria and yeast/mold on the finished pH and pack. Jar, pump, and wipe each change oxygen and consumer contamination, so name the pack on the request. Hair-cream and sunscreen briefs should mention oil load; face-wash briefs should mention anionic type. Do not raise dose to hide a failed test without a new challenge on the same chassis.
How to Specify with Esteem
- Name leave-on vs rinse-off vs sanitizer, pH, and primary surfactant (soap, SLES, nonionic).
- State packaging (jar, pump, wipe) and whether ocular or topical pharma rules apply.
- Request phenoxyethanol vs phenoxypropanol vs BKC vs iminodipropionate as named grades.
- Challenge-test the finished formula; do not scale a jar test to a 200 kg batch without a repeat.
- Name jar vs pump vs wipe so the challenge matches consumer contamination, not only a beaker of bulk.
Related personal-care chemistry: mild detergent bases, emollients, sunscreen emulsifiers.
Contact Esteem for samples, or custom synthesis for a non-catalogue preservative window.