Sodium Hydroxymethylglycinate is a chemical compound, a very small molecule that releases formaldehyde.

Chemical name sodium;2-(hydroxymethylamino)acetate

Safety
https://health.ec.europa.eu/system/files/2022-08/sccs_o_254.pdf

Ceriotti, L., Balzaretti, S., Barone, S., & Meloni, M. (2020). Eye irritation potential of microglycine and microglycine-containing ointments: an in vitro study on reconstructed human corneal epithelium. Clinical Ophthalmology, 257-267.

What it is used for and where
Cosmetics
Hair conditioning agent. A large number of ingredients with specific purposes can co-exist in a hair shampoo: cleansers, conditioners, thickeners, mattifying agents, sequestering agents, fragrances, preservatives, special additives. However, the indispensable ingredients are the cleansers and conditioners as they are necessary and sufficient for hair cleansing and manageability. The others act as commercial and non-essential auxiliaries such as: appearance, fragrance, colouring, etc. Hair conditioning agents have the task of increasing shine, manageability and volume, and reducing static electricity, especially after treatments such as colouring, ironing, waving, drying and brushing. They are, in practice, dispersing agents that may contain cationic surfactants, thickeners, emollients, polymers. The typology of hair conditioners includes: intensive conditioners, instant conditioners, thickening conditioners, drying conditioners.

Preservative. Any product containing organic, inorganic compounds, water, needs to be preserved from microbial contamination. Preservatives act against the development of harmful microorganisms and against oxidation of the product.
Synonyms: EC number 274-357-8

CAS: 70161-44-3