Not approved by the FDA
  
 
"...The industry has not provided safety data to FDA in order for the agency to consider approving it for use in the area of the eye."
 
The manufacturers haven't gone through the approval process yet...it's been almost 40 years since Coppertone put out it's first tanning product with DHA in it.
DHA is not FDA Approved for use on body areas covered by mucous membranes.
The CFR doesn't specifically define "areas covered by mucous membranes" so let me spell it out instead.
Lips
Inside your nose (nasal passages)
Mouth
Throat
Lungs
Labia – Wear protective disposable g-string bikini (or) your own choice of undergarment.
Again why hasn't DHA been approved for these areas?
 
It turns out that it's the same reason as before.
 
"The industry has not provided safety data to FDA in order for the agency to consider approving it for use on these exposure routes, including "misting" from tanning booths."
Again, 40 years and none of the manufacturers or an industry association haven't done this yet?
 
Inhaling the aerosol spray.
 
I'll make this really easy.
 
Don't inhale large quaniities of the spray/fumes. So best to not tan in a Spray Tan Booth.
Asbestos was the best insulation and fire proof substance around--until  discovering the various forms lung cancer it causes...
 
Do I have your attention?
I don't care what the manufacturers tell you.  I don't care if a third party lab approves that manufacturer's solution.  I don't care if DHA gets approved as an inhaled wonder drug. 
Spray technicians “wear your mask.’