Table 2.

Influence of some cosmetic constituents on preservation.

Component		Influence	Effects	Example	References
Solvent	Water	Negative	Main source of contamination	-	[20]
	Ethanol	Positive	Antimicrobial agent	Ethanol (more than 30%)
Thickener and emulsifiers based on lipids		-	-	Fats, oils, waxes
Surfactants	Cationic	Positive	Perturbation of cell membranes or increase in membrane porosity which also facilitates penetration of other antimicrobial substances	Alkylamines, quaternary ammonium compounds	[20]
	Anionic			Sulfates, sulfonates and carboxylates
	Amphoteric			Alkylamidobetain and alkylamidoglycinate
	Non-ionic			Fatty acids monoethanolamides, ethoxylated fatty alcohols and alkyl polyglucosides
Humectants		Positive	At concentrations of 5 to 10%, they can effectively reduce the amount of biologically available water.	Sugars (sorbitol), glycerol and gylcol	[20]
Gelling agents		Positive	Antimicrobial agent and reduction of biologically available water	Polyacrylic acids and hydroxypropyl methylcellulose	[20,172]
Emollients		Negative	Promote the growth of microorganisms	Silicon derivatives, proteins (milk proteins and albumin hydrolyzate)	[20]
Plants extracts and mineral raw materials		Positive or negative	Positive: polyphenols can exert antibacterial effect; Negative: source of contamination especially for spores, mycotoxins and Clostridium	Melissa officinalis extract, rosmarinic acid and phenylethyl alcohol	[20,100]