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Chemical formula: C3H8O3
Composition: Pure (then refined) glycerin can be isolated through processes like hydrolysis (soapmaking) and transesterification (a byproduct of making biodiesel). Glycerin can also be isolated via various chemical processes including from petroleum products, sugars, and starches. (Reference one [R1], Technical evaluation report glycerin handling/processing, 2013) (Reference two [R2], Farouk et al., 2024) (Reference three [R3], Augustine and Al-Samarrie, 2017)
Refinement and purification of glycerin is a joint, second process to manufacturing the product. According the Organic Material Review Institute, purification processes can include ion exchange, distillation, and decolorization. (R3)
Other common names: Glycerol, Glycerine, 1,2,3-Propanetriol
Function: Humectant, emollient, lubricant, solvent (for water-insoluble ingredients)
EWG Skin Deep rating: 1-2 (depends on usage) data-fair
PubChem GHS classification: primary hazards-none
EPA Safer Chemical rating: green circle
CIR Expert Panel report: safe
More: Glycerin is produced many ways and can struggle to find a classification that defines its manufacturing method. Products of glycerin can be classified, especially agriculturally, as synthetic or non-synthetic depending on how it is manufactured. Glycerin is also classified in other ways based on its manufacturing method like being organic and being from organic material. (Reference six [R6], Petition to remove glycerin from 205.605(b), 2015) Glycerin can be produced from sources like palm oil that can be certified sustainable like RSPO certified palm oil. (Reference four [R4], Roundtable on sustainable palm oil, n.d.)
Some of the manufacturing methods to make glycerin are as follows:
Hydrolysis (Greek hydro meaning "water" and lysis meaning "unbind") is the soap making process. For glycerin, ester bonds of the triglyceride are broken, isolating the glycerol backbone and fatty acids. Water and oil are mixed with an alkali agent (the traditional soap making process) or (water and oil are) under high pressure and temperature to break the bonds of the glycerol backbone and fatty acids. Steam hydrolysis is a process using high pressure to split the bonds of the triglyceride. (R1, R6)
Transesterification involves the reaction of a lipid (triglyceride) and an alcohol to produce fatty acid alkyl ester (FAAE) and glycerol. Triglycerides react to make diglycerides, which can be subsequently reacted to form monoglyceride and glycerol. (R2) (Reference five [R5], Lourinho and Brito, 2014, Figure one)
Glycerin can be produced by sugars, starches, and alcohols through microbial fermentation. (R1, R3)
Date created: May 27, 2026
Date updated:
What is vegetable glycerin made out of? A look at sources and processing. (2025, July 1). Elchemy. https://elchemy.com/blogs/personal-care/what-is-vegetable-glycerin-made-out-of-a-look-at-sources-and-processing.
More literature on topic
Glycerin
Guar gum
Chemical formula: Polysaccharide galactomannan
Composition: Cyamopsis tetragonoloba of family Fabaceae (Reference one [R1], Cyamopsis tetragonoloba (l.) taubert, n.d.) is a bushy legume with deep tap root system, leaves, flowers, and pods that contain seeds. (Reference two [R2], Tran, 2015) The guar kernel (seed) contains an outer husk, a germ, and an endosperm. (Reference three [R3], Mudgil et al., 2011) (Reference four [R4], Kawamura, 2008) The outer husk and germ are typically removed and guar gum powder is ground from the endosperm. (R3, R4) (Reference five [R5], Patel, n.d.) (Reference six [R6], Patel, n.d.) From harvest to milling the flour, the guar pods are dried and threshed; the seeds are cleaned, dehusked, and split to isolate the endosperm. The milling of the endosperm is end-result specific and can vary the final product like a fine to coarse finish of the flour. Guar gum powder, the endosperm, is mainly composed of high-molecular weight polysaccharide, galactomannan. Two sugars, a linear chain backbone of mannose and short side branches of galactose, make up the exo-polysaccharide. (R3, R4) (Reference seven [R7], Guar gum, n.d.)
Other common names: Cyamopsis tetragonoloba, galactomannan polysaccharide, cyamopsis gum, guar, guaran, gum cyamopsis, guar flour
Function: Thickener, texture modifier, foam boosting (with surfactants), emulsifying/stabilizing, conditioning (emollient)
EWG Skin Deep rating: 1-2 data-good
PubChem GHS classification: primary hazards-irritant
EPA Safer Chemical rating: green circle
CIR Expert Panel report: safe
More: Guar gum (guar endosperm) is composed of linear chain backbone beta-D-mannopyranosyl and side chains of alpha-D-galactopyranosyl. (R3, R4) An interesting fact about the galactomannan polysaccharide is that previous belief and supporting literature about the distribution of galactose side chain's placement patterns on the mannan backbone were regularly intervalled. However, subsequent experimentation and research like enzyme degradation, computer simulation, and spectroscopics indicate a more random distribution of the side chains. (R3) (Reference eight [R8], Mudgil et al., 2011, Figure 3)
Date created: May 27, 2026
Date updated:
More literature on topic
Duceac, I. A. and Coseri, S. (2022, December). Biopolymers and their derivatives: key components of advanced biomedical technologies. Biotechnology Advances. https://www.sciencedirect.com/science/article/abs/pii/S0734975022001525.
Rayment, P. and Ellis, P. R. (2003). Gums - nutritional role of guar gum. Encylcopedia of Food Sciences and Nutrition (Second Edition).
Science Direct topic Guar Gum in subject area biochemistry, genetics, and molecular biology. https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/guar-gum.
Science Direct topic Guar Gum in subject area nursing and health professions. https://www.sciencedirect.com/topics/nursing-and-health-professions/guar-gum.
References
Glycerin
Reference one [R1]. Technical evaluation report glycerin handling/processing. (2013, June 10). United States Department of Agriculture. https://www.ams.usda.gov/sites/default/files/media/Glycerin%20Petition%20to%20remove%20TR%202013.pdf.
Reference two [R2]. Farouk, S. M., Tayeb, A. M., Abdel-Hamid, S. M. S., Osman, R. M. (2024). Recent advantages in transesterification for sustainable biodiesel production, challenges, and prospects: a comprehensive review. Environmental Science and Pollution Research. https://pmc.ncbi.nlm.nih.gov/articles/PMC10881653/.
Reference three [R3]. Augustine, T. J. and Al- Samarrie, C. (2017). Glycerin. Organic Materials Review Institute. https://www.omri.org/glycerin-0
Reference four [R4]. Roundtable on Sustainable Palm Oil. (n.d.). https://rspo.org/.
Reference five [R5]. Lourinho, G., Brito, P. S. D. (2014, December). Advanced biodiesel production technologies: novel developments. Reviews in Environmental Science and Bio/Technology. https://www.researchgate.net/publication/269820631_Advanced_biodiesel_production_technologies_novel_developments.
Reference six [R6]. Petition to remove glycerin from 205.605(b). (2015, April). United States Department of Agriculture. https://www.ams.usda.gov/sites/default/files/media/HS%20Glycerin%20Final%20Rec.pdf.
[EWG reference]. Skin deep glycerin. (n.d.). Environmental Working Group. Retrieved on January 14, 2026. https://www.ewg.org/skindeep/ingredients/702620-GLYCERIN/.
[GHS classification reference]. Compound gycerol. (2004, September 16). National Library of Medicine. Retrieved on January 14, 2026. https://pubchem.ncbi.nlm.nih.gov/compound/Glycerol.
[EPA reference] Safer Chemical Ingredients List. (n.d.). United States Environmental Protection Agency. Retrieved on January 14, 2026. https://www.epa.gov/saferchoice/safer-ingredients.
[CIR reference]. Becker, L. C. et al. (2019). Safety assessment of glycerin as used in cosmetics. International Journal of Toxicology. https://cir-reports.cir-safety.org/view-attachment/?id=ad7dbaa1-8e74-ec11-8943-0022482f06a6.
Guar Gum
Reference one [R1]. Cyamopsis tetragonoloba (l.) taubert. (n.d.). United States Department of Agriculture. Retrieved on January 14, 2026. https://plants.usda.gov/plant-profile/CYTE11.
Reference two [R2]. Tran, G. (2015). Guar (cyamopsis tetragonoloba) forage, seed and meal. Feedipedia. https://www.feedipedia.org/node/311.
Reference three [R3]. Mudgil, D., Barak, S., and Khatkar, B. S. (2011, October 4). Guar gum: processing, properties, and food applications-a review. Journal of Food Science and Technology. https://pmc.ncbi.nlm.nih.gov/articles/PMC3931889/.
Reference four [R4]. Yoko Kawamura, Ph.D. (2008). Guar gum chemical and technical assessment. Food and Agriculture Organization of the United Nations. https://www.fao.org/fileadmin/templates/agns/pdf/jecfa/cta/69/Guar_gum.pdf.
Reference five [R5]. Patel, B. (n.d.). The chemistry of guar gum powder: what makes it so versatile? Agro Gums. https://www.agrogums.com/blogs/chemistry-of-guar-gum-powder-what-makes-it-so-versatile.
Reference six [R6]. Patel, B. (n.d.). From field to final product: the step by step process of making guar gum powder. Agro Gums. https://www.agrogums.com/blogs/from-field-to-final-product-the-step-by-step-process-of-making-guar-gum-powder.
Reference seven [R7]. Guar gum. (n.d.). Ataman Chemicals. https://atamankimya.com/sayfalar.asp?LanguageID=2&cid=3&id=13&id2=10893.
Reference eight [R8]. Mudgil, D., Barak, S. and Khatkar, B. S. (2014, March). Guar gum: processing, properties and food application-a review. Figure three. Journal of Food and Science Technology. https://pmc.ncbi.nlm.nih.gov/articles/PMC3931889/figure/Fig3/.
[EWG reference]. Skin deep cyamopsis tetragonoloba (guar) gum. (n.d.). Environmental Working Group. Retrieved on January 14, 2026. https://www.ewg.org/skindeep/ingredients/701726-CYAMOPSIS_TETRAGONOLOBA_GUAR_GUM/.
[GHS classification reference]. RefChem guar gum. (n.d.). National Library of Medicine. Retrieved on January 14, 2026. https://pubchem.ncbi.nlm.nih.gov/compound/Guar-Gum.
[EPA reference]. Safer Chemical Ingredients List. (n.d.). United States Environmental Protection Agency. Retrieved on January 14, 2026. https://www.epa.gov/saferchoice/safer-ingredients.
[CIR reference]. Johnson Jr, W. et al. (2015). Safety assessment of galactomannans as used in cosmetics. International Journal of Toxicology. https://cir-reports.cir-safety.org/view-attachment/?id=e6a4d57d-8e74-ec11-8943-0022482f06a6.