Geogard® ECT

What is it? Geogard® ECT is a liquid natural broad-spectrum preservative from Arxada.

It is comprised of (source: Arxada):

  • Benzy alcohol: 77–86%
  • Salicylic acid: 8–15%
  • Glycerin: 3–6%
  • Sorbic acid: 1–4%

It is also sold under many other names like Preservative Eco, Mikrokill ECT, and Plantaserv M, so be sure to check the INCI on what you’re purchasing.

Geogard® ECT is part of the Geogard® line; the “ECT” is important as the different products within the line all have different INCIs. Other Geogard® products include Geogard Ultra®, Geogard® 221, Geogard® 111S, Geogard® 111A, and Geogard® Boost PHC.

INCI Benzyl Alcohol (and) Salicylic Acid (and) Glycerin (and) Sorbic Acid
Appearance Pale yellow liquid
Usage rate 0.6–1%
Scent Almondy/marzipan-y
pH Effective from 3–8.

Geogard® ECT will cause the pH of your formulations to drop.

Solubility While the product description on UL Prospector says Geogard® ECT is water soluble (as of May 2024), the data sheet states that it works best in emulsified systems.

In my experience, Geogard® ECT does not mix well into totally hydrous formulations like watery serums and room sprays.

Why do we use it in formulations? Geogard® ECT protects our formulations from microbial spoilage (bacteria, yeast, fungus); I’ve found it to be an effective and easy-to-use natural preservative option.
Do you need it? You should have at least one broad-spectrum preservative; Geogard® ECT is a decent choice if you prefer natural preservatives and don’t mind the almondy scent.
Refined or unrefined? Geogard® ECT only exists as a refined product.
Strengths Unlike many natural preservatives, Geogard® ECT has a maximum functional pH range of 8 (most natural preservatives require an acidic pH to function well).

The manufacturer lists lip products as a possible application.

Weaknesses Noticeable almondy scent that can get stronger as the formulation ages.

Can cause the pH of a formulation to drop so much that it needs to be raised (dropping to below 4 is not uncommon). This can also be problematic if your emulsifier doesn’t work at lower pHs as your emulsion could break when the preservative is added, so you’d need to include a base in the formulation to prevent that large pH drop before you added the preservative.

Due to the salicylic acid content, Geogard® ECT cannot be used in products for children under 3 except for shampoo.

If you are using Geogard® ECT to preserve a formulation that contains salicylic acid as a skincare active, the salicylic acid content in the preservative will count towards the maximum allowable concentration of 2%. If we assume Geogard® ECT contains 15% salicylic acid, when used at 1%, the overall formulation will contain 0.15% salicylic acid. This leaves room for 1.85% additional salicylic acid.

Alternatives & Substitutions You’ll need another broad-spectrum preservative. Liquid Germall™ Plus is an effective, versatile choice, but it isn’t natural. Natural alternatives include Geogard Ultra™; and Euxyl k 903, though both have a lower effective pH range, and Geogard Ultra™ requires a buffer system to prevent downwards pH drift over time.
How to Work with It Include Geogard® ECT in the cool down phase of your formulations, and ensure the final pH of the formulation is the in 3–8 range.
Storage & Shelf Life Stored somewhere cool, dark, and dry, Geogard® ECT should last at least a year.
Tips, Tricks, and Quirks Looking for a natural way to add an almondy scent to your formulation? Preserve it with Geogard® ECT!
Recommended starter amount 30mL (1fl oz)
Where to Buy it Purchase Geogard® ECT from an online DIY ingredient supplier. It can be helpful to do a Google search for the INCI as this product is sold under a variety of names.

Some Formulations that Use Geogard® ECT


Posted on

August 29, 2022