AOS, LAS,
K12, AES and other anionic surfactant have good foaming  ability; by
comparison, foam abilities of AOS14-16& AES are the best. Under  the
condition of hard water and soft water, AOS14-16, AOS14-18
and AES foaming  force changed little. Due to LAS and K12 hard water
resistant ability is  poorer, foaming force decreased significantly in
hard water. In the presence of  sebum, AOS foaming ability is slightly
higher than AES and AS.