| What is it? | Liquid Germall™ Plus is a broad-spectrum preservative that is effective in a wide variety of formulations and pH environments.
Liquid Germall™ Plus is approved for leave-on and rinse-off products in the USA & Japan, but not aerosol products (aerosol products are not the same as mists or spritzes). It is approved for rinse-off products in the EU, and not approved for use on children under 3. Liquid Germall™ Plus is a patented product made by Ashland. |
| INCI | Propylene Glycol, Diazolidinyl Urea, Iodopropynyl Butylcarbamate |
| Appearance | Viscous clear liquid |
| Usage rate | 0.1–0.5%, though Ashland reports efficacy as low as 0.06% and recommends higher concentrations for more complex formulations. I’ve never encountered spoilage at 0.5%, even in very challenging formulations. |
| Scent | Nothing noticeable in end products |
| Approximate Melting Point | Liquid at room temperature |
| pH range | 3–8 |
| Charge compatability | Cationic, anionic, and non-ionic compatible. |
| Solubility | Liquid Germall™ Plus is water-soluble. |
| Why do we use it in formulations? | Liquid Germall™ Plus protects our products from microbial spoilage (bacteria, yeast, fungus). I’ve used it for years in all kinds of formulations and have found it to be an incredibly reliable, effective preservative.
In addition to its versatility in terms of efficacy, it also works over a broad pH range, generally negating the need to test the pH of your end product unless you know it contains high concentrations of extremely acidic or basic ingredients. If you don’t want to invest in pH testing equipment, this is a great added bonus! |
| Do you need it? | I highly recommend it. Even if you don’t want to use it forever, it’s a great starter preservative, allowing you to familiarize yourself with other aspects of making and formulating without worrying about preservation. |
| Refined or unrefined? | Liquid Germall™ Plus only exists as a refined product. |
| Strengths | It is very effective at low concentrations, and functions in a wide variety of formulations. According to Ashland, Liquid Germall™ Plus “is compatible with virtually all cosmetic ingredients including complex ingredients such as proteins and surfactants.” |
| Weaknesses | Liquid Germall™ Plus can be very hard to find outside of North America. |
| Alternatives & Substitutions | Please read this FAQ. |
| How to Work with It | Add Liquid Germall™ Plus to the cool-down phase of your formulations; do not heat above 50°C (122°F). |
| Storage & Shelf Life | Stored somewhere cool, dark, and dry, Liquid Germall™ Plus should last at least two years. |
| Tips, Tricks, and Quirks | Diazolidinyl Urea is considered safe up to 0.5%; given it is just a component of the overall product with a maximum usage rate of 0.5%, we’re well below that.
Iodopropynyl Butylcarbamate is present at 0.004% in Liquid Germall™ Plus; 0.5% usage means a finished formulation will contain 0.002% Iodopropynyl Butylcarbamate. This is well below the CIR limit of 0.1%. |
| Recommended starter amount | 30g (1.06oz) |
| Where to Buy it | Buy it from an online DIY ingredient supplier. |
Want to learn more about preservatives and compare them? Check out this chart!
