I manufacture and sell hair care and use sodium hydroxymethylglycinate and I am often up against companies that claim this ingredient is extrememly bad and should not be used as it it is a formaldahyde and your explanation is fantastic. I would like to be able to use this explanation with my staff there is 3 staff members and from this allow them to explain to stores that may query the use of sodium hydroxymethylglycinate. I find this preservative easy to work with and effective and the usage amount is small. A lot of our opposition have gone to phenoxyethanol which I believe has it own set of advantages and disadvantages. I really do appreciate your help and to allow us to use your explanation of sodium hydroxymethyglycinate.
My offer, bearing in mind that this is amongst the many “paraben-alternatives” I have in my portfolio:
Sodium hydroxymethylglycinate is permitted at concentrations up to 0.5% in the European Union. This means that its safety has been rigorously assessed by the EU Commission’s independent panel of experts. This assessment allows for a margin of safety of at least 100 times in the maximum permitted concentration, and the product is more typically used at between 0.2 – 0.4% (as active sodium HMG). The product has the potential to release very low levels of formaldehyde under certain circumstances, if the product were stored under unsuitable conditions, for example. At a use concentration of 0.2% active material, even if this released all the potential formaldehyde, it would only produce a maximum of 0.04% (approximately). Typical levels of free formaldehyde would be unlikely ever to exceed 0.005%, even when used at the maximum permitted concentration. These are formaldehyde levels in the actual product in the container. When the product is actually in use, especially in the case of hair care products, the potential for ANY formaldehyde to be in contact with skin is extremely low, and need not be cause for concern, and this is the important consideration. Phenoxyethanol is another excellent preservative, adjudged to be safe for use in cosmetics by the EU expert panel.
I agree with everything you said but it still begs the question…
If Phenoxyethanol is an excellent preservative, why would anyone use Sodium hydroxymethylglycinate? I suspect the answer is because while it is an excellent preservative it doesn’t always work.
I have never used sodium hydroxymethylglycinate, but I imagine being a salt its effectiveness is probably affected by pH. Phenoxyethanol can be inactivated by some surfactants and is not very good against fungi. Preservation is often tricky and all formulators need to have a range of preservatives up their sleeves.
Dene covered it thoroughly. The only things I noted using it is that when used with peppermint essential oil it turns the product very pink, with lemongrass it turns the product dark brown overnight and it didn’t work consistantly with natural ingredients.
A good point, Kayla. As the questioner obviously doesn’t have an issue with any discoloration, I omitted to mention that formaldehyde reacts rapidly with proteins and so may be unsuitable for use with natural raw materials that have some protein content. In the case of formaldehyde donors, there is a very low concentration of free formaldehyde in equilibrium with the intact material in aqueous solutions. When the free formaldehyde reacts with proteins (or anything else), it disturbs the equilibrium and causes more breakdown. Formaldehyde donors should not be used in combination with proteins for this reason.
Perry – there are two possible responses:
1) As you said, Phenoxyethanol doesn’t always work (and, weight for weight, Sodium HMG is more effective than PE and has a broader spectrum of activity), and
2) Sodium HMG is ALSO an excellent preservative
Both are valid responses and equally true. All preservatives have benefits and shortcomings, and there is no universal preservative system.