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Emulsion stability troubleshooter

Pick the symptom you can see and, if you know it, when it appeared. You get the causes that are physically plausible for that symptom, the checks that separate them, and the direction each one points. It does not diagnose your batch: several of these causes look identical in the jar.

This troubleshooter narrows where to look. It does not diagnose your batch, it does not identify a root cause from these answers alone, and it never states that a change will fix the formula.

1 · What is the batch doing?

Describe what you can see. The visible defect decides which physical mechanism is in scope.

Choose a symptom to see the causes that are physically plausible for it, what separates them on the bench, and what has to be validated before anything is concluded.

Use this when

A cream or lotion separated, creamed, thinned or turned grainy and you need a structured place to start.
One batch failed and the previous ones held, and you need to separate a process cause from a formula cause.
A stability sample moved at 40 °C or on freeze–thaw and you need to know what that points at.
You need to brief a supplier or a contract manufacturer in mechanism terms rather than in symptoms.

How the output is produced

Symptom first — the visible defect decides which physical mechanism is even in scope.
Onset is a second, optional axis. It re-orders emphasis; it never removes a cause, because removing a cause would be a diagnosis.
Each cause carries its mechanism, the checks that would confirm or exclude it, and a direction to investigate.
Creaming reasoning follows Stokes' law: droplet size, phase density difference and continuous-phase viscosity.
Emulsifier reasoning follows the required-HLB pairing logic and the fatty-alcohol network that builds cream body.
Every path ends at your own controlled comparison and stability programme.

What this page does not determine

It does not diagnose your batch. It lists causes that are plausible for the symptom, in no order of certainty.
It calculates nothing: no emulsifier level, no blend HLB, no ratio, no viscosity target, no shelf life.
It does not predict whether a change will hold — only a controlled trial and a stability programme establish that.
It makes no safety, irritation, preservation-efficacy or therapeutic claim about any material listed.
It does not establish permitted use in Canada. That is a Cosmetic Ingredient Hotlist question for the specific substance and product type.

Relevant Allzone products

These are catalogue identities relevant to this decision. A listing here is not a statement that the material is suitable for your formula, and it is not a permitted-use, safety or performance claim.

Ask for a quotation or a specification

Where this comes from, and what it cannot tell you

Stokes' law for the sedimentation / creaming velocity of a dispersed droplet
Supports: That creaming rate rises with the square of droplet radius and with the density difference between the phases, and falls as the continuous-phase viscosity rises. This is why droplet size, oil-phase density and continuous-phase structure are the three levers.
Limitation: Stokes' law assumes isolated, rigid, spherical droplets in a Newtonian medium. A real cosmetic emulsion is concentrated, polydisperse and non-Newtonian, so the relationship explains direction, never a shelf-life number.
Universal · Classical colloid physics; stable.
Griffin's HLB system for non-ionic emulsifiers, and manufacturer technical data sheets
Supports: That non-ionic emulsifiers are characterised by a hydrophilic–lipophilic balance value, that an oil phase has a required HLB, and that a pair of emulsifiers is blended to meet it.
Limitation: HLB is an empirical index for non-ionic systems. It does not describe ionic or polymeric emulsifiers, it ignores the crystalline network that gives a cream its body, and matching HLB does not by itself produce a stable emulsion.
Universal · Use the HLB value on the technical data sheet for the grade you actually buy.
Published cosmetic stability-testing practice (accelerated, room-temperature, cycling and freeze–thaw protocols)
Supports: That physical stability is established by a defined stability programme on the finished product in its final packaging, including accelerated and real-time storage.
Limitation: Accelerated storage is an indicator, not a prediction. An accelerated result does not establish real-time shelf life, and a passed protocol applies only to the formula, batch and pack tested.
International · Follow the protocol your own quality system defines.
Health Canada — Cosmetic Ingredient Hotlist
Supports: That restricted and prohibited substances in cosmetics sold in Canada are defined by the Hotlist, and that the Hotlist entry — not this page — is the authority for any concentration limit or labelling condition.
Limitation: The Hotlist states restrictions. It never states that an unrestricted ingredient is effective, safe in your formula, or approved for your product.
Canada · Consult the current published Hotlist before every formulation decision.