So is propylene glycol safe??

Propylene glycol can enter the bloodstream by inhaling air containing mists or vapors from this compound or through skin via direct contact with it. Consumption of propylene glycol can also be a way for the compound to enter the bloodstream. Propylene glycol will be broken down by the body within 48hours.

According to the FDA (Food and Drug Administration), Propylene glycol is GRAS (generally recognized as safe). Base on the results of human irritation and sensitization test, it the CIR Expert panel concluded that Propylene Glycol is safe to be used in cosmetic products at concentration up to 50%.  However, it was also noted that patients with diseased skin (e.g. eczema) may be susceptible to developing irritation/sensitization reaction to Propylene Glycol.

In 2003, the National Toxicology Program’s Centre for the Evaluation of Risk to Human Reproduction (CERHR) Expert Panel reviewed the reproductive and developmental effect of Propylene Glycol and concluded that there is “negligible concern for reproductive or developmental toxicity to humans.” 
Studies were also conducted on dogs and rats, which were fed doses of PG ranging from 2 to 5 grams per kg of body weight per day. The results showed that there is no links of Propylene Glycol to cancer. Hence, Cosmetic Ingredient Review Expert Panel concluded that there was no carcinogenic risk with low levels of ingestion of PG.