A cosmetic chemist on reddit pointed out that they don't use preservatives in their products. They said:

The other possibility is contamination, because it doesn't contain a preservative. However waterless products don't need as much preserving as water-containing products..., personally I wouldn't risk launching a mass product without a preservative. Though it's almost guaranteed EOS has done microbiological testing.

Can't win for trying, I guess. Preservatives are great at stopping stuff like mold, but they don't win over the "all natural" crowd too often.