Assessment of DHA in self-tanning creams applied in spray booths
3 Techniques
This study covers three different techniques for applying self-tanning products.
- Manual turbine spray, a technique where an operator applies self-tanning products using a hand-held spray gun.
The other two techniques mentioned in the project are automatic in special booths, where the self-tanning product is applied from either moveable or fixed nozzles.
- Third-generation booths are completely enclosed.
- Fourth-generation booths are open and the liquid is electrically charged before being sprayed on the customer.
3.1 Description of techniques
3.1.1 Manual turbine spray
3.1.1.1 Description of the technique
Figure 3.1 Manual turbine spray
Using the manual turbine spray principle, the customer goes into an open booth and then the liquid containing DHA is sprayed onto the customer by an operator. The system used for NERI's measurements for this project uses the turbine principle; the same as that used in the most modern manual spray systems on the market. The advantages of the turbine principle are described by the supplier:
- It is based on HVLP technology, i.e. High Volume air but under Low Pressure.
- It is faster to apply - a total of 2-3 minutes compared with up to 30 minutes for traditional air-brush systems - and the liquid dries faster.
- Spray width is 13 cm compared with 2 cm for traditional air-brush systems.
- Waste (overspray) is minimal.
- Very low lotion consumption - about 25 ml. per treatment compared with 100 ml for traditional air-brush systems.
- The aerosol/DHA cloud is minimal so that the customer and the operator are not exposed to unnecessary inhalation of the self-tanning product/DHA.
3.1.1.2 Preparation
The customer removes clothes and jewellery as well as any make-up. Paper briefs/panties can be worn. A cap is pulled over the hair so that all the hair is covered, and then it is drawn back so that the hairline and ears are uncovered with a hairline of about 1 cm. The customer then steps onto self-adhesive sandals which protect the customer's feet against over exposure when the customer moves around in the booth. Next, a barrier cream is applied to all areas of dry skin.
3.1.1.3 The spray treatment
The operator turns on the machine and holds the pistol horizontally. The operator must move her whole arm and not just her wrist so that the nozzle is always straight (at right angles to the customer either vertically or horizontally) in order to achieve uniform covering. This also means that the operator must squat or go down on her knees when spraying a customer's legs, and the operator must stand up when spraying the upper body.
The operator must always remember to squeeze the trigger fully before the spray hits the customer's body, and to release the trigger only after the spray is away from the body. This is called "fanning" and it avoids smudging on the customer. For larger areas "full strokes" must be used where the pistol is moved backwards and forwards on an area so that the area is hit twice (once backwards, once forwards). The pistol should always be held at a distance of about 15 cm from the customer's body.
Spraying itself is in the following order:
- Legs from the front
- Upper body and neck
- Arms
- Legs from behind
- Back and neck
- Arms
- Side of upper body
- Face, when the customer is asked to close her eyes, purse her lips, and hold her breath while the operator counts to three.
Any wet areas on the customer are air dried by pointing the pistol towards the areas without squeezing the trigger. Treatment has now been completed and the customer can put on loose clothes or a kimono.
3.1.1.4 Manufacturer's safety instructions
The manufacturer's safety instructions recommend that the operator wears a dust mask while using a manual spray system or during automatic application (2). During treatment of face and neck, the customer is asked to close her eyes, purse her lips, and breathe through small filters inserted in both nostrils.
3.1.2 Third-generation booths (closed booths)
3.1.2.1 Description of the technique
Figure 3.2 Third-generation spray booth
Third-generation booths have two compartments. The customer hangs her kimono in the outer compartment and activates the spray program. The inner compartment has three rows of nozzles, located so that the customer is sprayed over her entire body without having to turn around. Treatment takes about six seconds using 60 ml of lotion.
3.1.2.2 Preparation
The customer removes clothes and jewellery as well as any make-up. A bathing cap is pulled over the hair and adjusted so that it just reveals the hairline. Protective cream can be applied to nails, hands, and feet to avoid discolouring.
3.1.2.3 Spray treatment
The customer hangs her kimono in the outer compartment and activates the program. The customer enters the inner compartment. After a 15-second countdown, treatment commences with the self-tanning product being sprayed out of nine nozzles. Treatment lasts about six seconds during which the customer stands with raised arms and palms facing each other, and lifts her right, then her left leg alternately. The customer then returns to the outer compartment and closes the door behind her. At the moment treatment ceases, there is a thick aerosol mist in the inner compartment. The quicker the door is closed, the quicker the aerosol mist is isolated. Extraction starts in the inner compartment as soon as the treatment is over. The customer spreads any excess product over her body, puts the kimono on again and exits the booth. After treatment the inner compartment is cleaned automatically so that the surplus spray mist is removed from the air, and the self-tanning product is cleaned from the walls and floor of the booth.
3.1.2.4 Manufacturer's safety instructions
The customer is asked to keep her eyes and mouth shut during treatment.
3.1.3 Fourth-generation booths (open booths)
3.1.3.1 Description of the technique
Figure 3.3 Fourth-generation spray booths
Fourth-generation spray booths are fully automatic. In contrast to third-generation booths, fourth-generation booths are open.
The self-tanning product is charged to 40,000 V and sprayed out through two vertical rows of nozzles. The spray nozzles are located in a tower on one side of the booth so that the customer has to turn around to be sprayed on the front and the back. Charging means that the aerosol is more accurate and less lotion is used for each treatment. According to the Danish agent, 99 per cent of the aerosol hits the customer and only 15 ml of lotion are used per treatment. The aerosol drops are ten-times smaller than in third-generation booths.
The customer stands on two earthed metal plates so that the lotion hits the customer very accurately using electrostatic energy.
3.1.3.2 Preparation
The customer removes clothes and jewellery as well as any make-up. A cap or paper briefs/panties may be put on. The cap is pulled down over the hair so that all the hair is covered, and then pulled back to leave the ears and a hairline of about 1 cm free.
3.1.3.3 Spray treatment
The customer stands in front of the spray tower with her feet placed on the two earthed metal plates and presses the start button. The nozzles in the tower spray lotion on the customer for 2, 2½ or 3 seconds. The customer turns her back towards the spray tower and is again sprayed for 2, 2½ or 3 seconds. The customer receives instructions throughout the process from loud speakers in the open booth. The treatment takes a total of 4½ to 6½ seconds, including the time it takes for the customer to turn around.
3.1.3.4 Manufacturer's safety instructions
In material for operators, the manufacturer recommends that customers use disposable briefs/panties, nose filters and eye protection.
3.2 Safety instructions
3.2.1 General remarks on enterprises' safety instructions
Instructions from operators to customers are more or less the same, irrespective of the salon. Most places recommend that customers:
- avoid inhaling the spray mist
- shut their eyes and mouth during spraying.
A manufacturer provides the following instructions for operators for manual application:
“Separate extractors are not necessary, but if you spray more than five customers per day, an external extractor should be used or an extractor booth with built-in filters. The operator should wear a dust mask if a manual spray system is used or if the operator is present during autospray" (2).
Another manufacturer recommends for expectant mothers: "Tanning spray is a non-toxic, food-approved product. Although [the manufacturer] has no information from any health authority that indicates harmful effects on pregnant women, we recommend that you consult your doctor before receiving treatment with self-tanning products in booths" (3).
The same manufacturer’s recommendations for diabetics: "[The manufacturer] has no information from any health authority that indicates risks for diabetics. However, [the manufacturer] recommends that anyone with a medical condition should contact their doctor before receiving treatment with self-tanning products in booths"(3).
3.2.2 Safety instructions from the authorities
As a result of the increasing popularity of self-tanning booths, the US Food and Drug Administration (FDA) recommends that customers ask for special protection in order to avoid exposure of the eyes, lips and mucous membranes and in order to prevent inhalation/ingestion, for example by asking for nose filters.
3.2.3 Advice for customers from personnel
Most manufacturers of self-tanning booths have their own website on which they publish instructions and recommendations by replying to FAQs. Operators are trained in the same safety instructions and in how to reply to questions. On the first visit, the operator will usually ask the customer the following health-related questions (1):
Do you know how self-tanning works?
This enables the operator to explain how DHA works.
What is your normal skin colouring (light, medium, dark)?
The darker the skin colour the greater the effect of DHA.
What type of skin do you have (dry, normal, greasy)?
The drier the skin, the more effectively the DHA will penetrate the skin. This also means that areas of dry skin such as feet, knees, elbows, hands and fingertips get dark smudges. It is suggested that dry areas are protected with a barrier cream before spraying commences.
Do you want to be brown for a special occasion?
If the customer is to go on vacation, the salon personnel should mention that the self-tanning product will not protect against the sun.
Do you use a solarium?
If the customer wants to combine solarium with self-tanning, the salon personnel/manufacturers will recommend that the customer go to the solarium before treatment with self-tanning products. This is because heating the body will open the pores and make the skin more receptive to DHA, and the customer should avoid sweating immediately after application of DHA.
Do you suffer from asthma?
Some asthmatics can also be allergic to DHA. Although customers are asked not to inhale DHA, the salon personnel/manufacturers recommend that the customer bring an inhaler in case of accidents. Some suppliers of self-tanning products also ask asthmatic customers to seek advice from their doctor before treatment.
Are you pregnant?
Expectant mothers are recommended not to use self-tanning products during the first 12 weeks of pregnancy.
Are you breast-feeding?
Nursing mothers are asked to cover their breasts during application to ensure that the child does not ingest DHA residues.
Do you have very sensitive skin?
If the answer is yes, and the customer has not previously had DHA treatment, it may be advisable to make a small test (usually behind the ear) to see whether the skin reacts to the DHA.
Do you have a skin condition?
If the customer has a skin condition such as psoriasis or eczema, DHA will penetrate the dry areas with this condition more intensively. The areas can be protected with barrier cream, but if the condition is widespread, the customer should seek advice before using self-tanner.
Do you have any cuts or grazes?
Open cuts should be protected with plasters and healing cuts with barrier cream.
Would you like to buy a nose filter?
The customer should be made aware that DHA should not be inhaled. The operator can therefore offer the customer a nose filter through which she can breathe during treatment.
Figure 3.4 Nose filters
In the US, the National Tanning Training Institute offers courses leading to certification. These are popular as some US states require personnel training before issuing licences to beauty salons (1).
Version 1.0 September 2006, © Danish Environmental Protection Agency