ABC news reports that chemicals in the tanning sprays may contain chemical dihyroxyacetone (DHA) that has been shown by scientific studies to cause genetic mutation if exposed directly to cells.

Federal Drug Administration FDA approved the color additive DHA which turns skin color brown in 1970's for external skin use only. The chemical was approved as an additive to skin lotions

Human studies have not been conducted but the health risk of causing genetic mutations on humans are a concern.
"these compounds, in some cells, could actually promote the development of cancers or malignancies," said Dr. Rey Panettieri, a toxicologist and lung specialist at University of Pennsylvania, according to ABC news, adding "if that's the case then we need to be wary of them."

humans my be directly exposed to dihydoxyacetone (DHA) by inhaling the chemicals while being spray tanned. Once DHA enters the lungs and is then absorbed into the bloodstream, the chemicals could damage DNA and cause tumors.

Scientist claim DHA may exacerbate asthma and other lung problems such as chronic obstructive pulmonary disease (COPD) and emphysema.

Researchers expressed concerns over the safety after looking at the test conducted on cells in the lab.