| Methods
and Materials Hair coloring products evaluated in this study are available nationally and were purchased at pharmacies in New Orleans. Methods Used to Test Hair Coloring Cosmetics Testing the lead content of products involved the following preparation: One gram of hair dye sample was mixed with 10 mL Trace Metal Grade (TMG) HNO3 and placed into a CEM MDS 2000 (635 watt) microwave digester. The microwave parameters were set for two stages of operation. In stage one, power was set at 80% for 20 minutes, with 10 minutes time at pressure (TAP) of 30 psi. In stage 2, power was set at 90% for 20 minutes, with 10 minutes' TAP of 60 psi. Cool-down was completed when the pressure reached 10 psi. Before analysis, the samples were diluted (1:8) with 18 megohms water. Analysis was done with a Spectro Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES). The high lead samples were introduced into the plasma with a Meinhard concentric glass nebulizer. For the low lead samples, a Spectro ultrasonic nebulizer was used. The LQD for these was determined to be 15 mcg per liter. The wipe study was conducted using a protocol developed for the study of children at day care centers. Pretreated, antibacterial, moist towelettes (13.75 cm x 20 cm), were used to collect the wipe samples. The extraction was done by adding 20 mL of 1M TMG HNO3 and shaking for two hours on a reciprocal platform shaker and filter. Analysis was conducted with a Spectro ICP-AES using a Meinhard nebulizer. Lead content of the products. Product samples were prepared according to the protocol given in the box below. Duplicate samples were run for all products tested. Wipe sample collection. The products containing lead acetate were used according to manufacturers' instructions. The exposure procedures were designed to replicate and follow the manufacturers' usage instructions. Samples were obtained by wiping surfaces according to a laboratory protocol (see box).10 A single towelette was used for wiping, and each towelette was then placed into individually labeled 120 mL polypropylene specimen containers with polyethylene caps. Hand testing. Disposable gloves were worn while testing hands. Background samples were obtained by wiping gloved hands before collecting hand samples. The test involved wiping the palm and anterior parts of the fingers on both hands. Unused wipes (control blanks) were treated in the same manner as the test samples. The analytical results were expressed as micrograms of lead per hand. Surface samples. Surfaces that were touched by the user were also tested. The areas tested were the comb used as directed in the hair, the handle of the blow dryer, the exterior surface of the product container, and the faucet that was touched while washing the hands after using the hair coloring product. The earpiece of the receiver of the laboratory phone was also wipe sampled after a call at the end of the experimental period. To collect a sample, wiping was done in a horizontal direction and then with a vertical motion. The area of each surface was measured and the analytical results were expressed in micrograms of lead per square foot. |
