Low Toxicity

• One important property of glycerol (glycerin) is its low toxicity to humans. The Material Safety Data Sheet for glycerin indicates that it readily biodegrades, making it environment-friendly.
  
  

Easy Procurement

• Science JRank notes that glycerin naturally exists in fats and oils, such as coconut and olive oil. It is also a natural byproduct of the soap-making process, which manufacturers often remove for use in more profitable skin care products, or retain as an ingredient in certain soaps.
  
  

Solvency

• According to the SEVAS Bioinformatics Institute, glycerin is a good solvent for organic and inorganic solids. This means that glycerin can improve the laundry soap's ability to dissolve various soils, clean without leaving residue, and prevent the separation or deterioration of various ingredients.
  
  

Softening Qualities

• Glycerin can act as an emollient (softener) and texture enhancer in a laundry soap. According to the Soap and Detergent Association, softeners not only impart softness to fabrics, but also reduce fabric friction and static electricity
  
  

Hygroscopic Effect

• According to Biodiesel, glycerin is a hygroscopic substance, that is, it has the capacity to draw water from the air and retain moisture. It can therefore help ensure product homogeneity.
  
  

Stability

• Vegetable glycerin is stable under ordinary conditions of use and storage, according to the Material Safety Data Sheet.