To produce the instant bronzing colour in a self tan fluid necessitates the use of a colouring compound. Most manufacturers will use a cosmetic food dye. The brown tint is achieved by mixing together at least three colours, red, yellow and blue in varying proportions.
There are numerous tints of red, yellow and blue to choose from, but for use with DHA each one has to have a high percentage of resistance to the acidic effect of DHA and whatever pH reducer (eg citric acid) is used to achieve the desired pH level for the effectiveness of the DHA.
THE CAUSE OF FLUIDS HAVING A GREEN TINGE
1. ON THE BOTTLE NECK Some reds have quite a high evaporation level and when spilt around the neck of the bottle the red begins to be absorbed into the atmosphere, and leaves yellow and blue- which appears as a green, but since yellow will have slightly been affected it is actually a bluey green.
2. IN THE GUN OR STORAGE TANK Any metal components in a spray gun or storage tank will have a disastrous effect on the bronzing colour in a self tan. The acidity of the fluid will begin to penetrate carbonised metals and start corrosion, which will firstly absorb the most vulnerable colour which is red. All spray guns must be cleaned daily and dried thoroughly. Any metal storage tanks in spray booths are at risk from corrosion even aluminium. Stainless steel tanks are suitable if Grade 316 stainless steel is used.
3. ON THE BODY Ideally when a person is sprayed an instant brown colour is achieved. The reason for this is two fold.
1. Customer can see an instant tan
2. The operative has a guide to where the customer has been sprayed and an easy instant tan can be achieved.
On some people this instant bronzing can also appear to have a greeny tint. The reason for this is that when fluid is sprayed it is atomised by the speed of air drawing the fluid into a mixing chamber and then being mixed together at a ratio of approx. 16:1 (AIR : FLUID). (Different guns and air pressure will vary this ratio). The fluid is then applied to the skin. Ideally the skin needs to be slightly acidic for the effectiveness of DHA, but perspiration on most ladies bodies is heading towards an alkaline level. Highly atomised acidic fluid applied to an alkaline body can cause problems to certain reds that are used, in as much as body temperature (evaporation) and the tanning fluids acidic level are trying to combat an alkaline skin.
However, all of this colour activity, whether it be in the bottle (lid not replaced) in the gun ( gun not cleaned out regularly and thoroughly) or on alkaline skin (perspiration or just had a shower using soap) has no effect on the efficiency of the self tan fluid. The attitude that if a fluid has a greeny colour then it has gone off is all a myth.