Engineering Controls Database
Nail Salons – Control of Ethyl Methacrylate Exposures During the Application of Artificial Fingernails
The technique for application of artificial fingernails started in the late 1950s, but became popular in the early 1970s when manicurists began applying methyl methacrylate dental acrylic to fingernails to strengthen natural nails or create artificial nails [Gorton 1993]. Since then, artificial nail application has grown steadily. In 1993, there were 33,000 salons that did nails exclusively. This number did not include salons that perform artificial nail services in addition to offering other services (hair, massages, etc.). In 1993, there were 190,000 nail technicians, an increase of 9 percent from the previous year. The projected dollars spent for artificial nails and extensions was almost three billion dollars in 1993, more than double the total dollars spent for these services in 1989 [Drummey 1993].
In 1987, the National Institute for Occupational Safety and Health (NIOSH) initiated the SENSOR (Sentinel Event Notification System for Occupational Risks) program, a cooperative state-federal effort designed to develop local capability for the recognition reporting, follow-up, and prevention of selected occupational disorders. In 1990, the Colorado Department of Health identified three cases of asthma in cosmetologists. Artificial nail application appeared to be a common factor in these occupational asthma cases. As a part of the SENSOR program, Colorado requested NIOSH assistance in the evaluation and control of nail salon technician exposure.
There are many products used during the application of artificial nails, including the color coat remover, the liquid and powder of the artificial nails, the adhesives, primers, and color coats. Many of these products contain chemicals known to cause negative health effects [HESIS 1989].
Artificial nail products used to contain the liquid monomer and powdered polymer of methyl methacrylate. The monomer is an irritant of the eyes and mucous membranes, and has been found to cause dermatitis. High concentrations may cause central nervous system depression and unconsciousness. In 1974, methyl methacrylate was banned by the US Food and Drug Administration (FDA) for use in all nail products because it caused deterioration of nail plates, nail dislocation, and/or allergic dermatitis in both customers and nail technicians [Groton 1993]. However, in 1992, a study reported that methyl methacrylate was still found at least in trace amounts in some nail products [NIOSH 1992].
Many manufacturers of artificial nail products substituted ethyl methacrylate for methyl methacrylate as the main component for application of artificial nails. There is evidence that ethyl methacrylate is toxicologically similar to the liquid monomer and powdered polymer of methyl methacrylate [Oberly and Tansey 1985].
Ethyl cyanoacrylate is used in adhesives that are often used during artificial nail application. Ethyl cyanoacrylate can cause dermatitis, asthma, symptoms of irritation to the eye and mucous membrane, and the glues are toxic due to heat generation and degradation to formaldehyde and cyanoacetate [Shelly 1988].
After examining various controls, a commercially available recirculating downdraft manicure table with charcoal filters was purchased and evaluated [Model #0592M, Professional Fabricators, Inc, Cypress, California]. There were several other manufacturers of downdraft tables that used similar designs. The table evaluated was 3.4 feet long by 1.5 feet wide and 2.6 feet high. On the client's side of the table, a 52-inch wide padded arm rest was extended from the table. The client's side of the table was 2.6 inches higher than the technic1an's working surface, so the client's hands would extend over the downdraft face. The downdraft air exhausted through a perforated plate which was located 6.5 inches from the technician's side of the table. The perforated plate was 13 inches long, and 4.2 inches wide, with 67.3 percent void space. The air for the downdraft ventilation entered the table through the perforated plate. A small centrifugal fan was used for the downdraft flow. The measured average flow of downdraft air through the table as purchased was 62 cubic feet per minute (cfm), the average face velocity was measured at 160 ft/min. The air passed through a carbon filter, and exited the table though the bottom.
The ventilation of the manicure table was deemed inadequate due to the following factors: (1) leaks were detected around the charcoal filter, thereby allowing potentially contaminated air to escape before reaching the filter, (2) there was no indicator to notify the operator when the filter
needed replacing, nor was there a backup filter, (3) there was uneven air flow across the face of the downdraft opening, and (4) the volume of air was not adequate to overcome room air currents.
Modification to the commercially available manicure table
The following modifications were made to the commercially available manicure table: (1) the downdraft air volume was increased from 62 to 235 cfm by using a larger fan, (2) the plenum was enlarged such that the plenum velocity equaled half the perforated plate velocity for more consistent air flow rates at the face of the table, (3) the charcoal filters were removed and an exhaust system to the outdoors was incorporated, and (4) an extension around the duct leading to the perforated plate at the face of the table was added. The extension brought the duct (downdraft plenum) on the technician's side up to the height of the client's side of the table, up approximately 2.6 inches.
The added outdoor exhaust system incorporated approximately 8 feet of flexible corrugated duct. The duct connected the downdraft exhaust from the manicure table to an opening in an outside wall which was previously an exhaust for the building.
Drummey C, ed . The history of nail care. Nails Magazine fact book, Bobit Publishing Co., Redondo Beach, CA. pp 1-12.
Gorton A . The history of nail care. Nails Magazine, Bobit Publishing Company, Redondo Beach, CA. February 42-44.
HESIS . Artificial fingernail products a guide to chemical exposures in the nail salon. Berkeley, CA. Hazard Evaluation System and Information Service, California Occupational Health Program.
NIOSH . Hazard evaluation and technical assistance: Haute Nails, Norman, OK. Cincinnati, OH, U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health, NIOSH Report No.
Oberly R, Tansy MF . LC50 values for rats acutely exposed to vapors of acrylic and methacryllc acid esters. J Tox Environ Hlth 16(6) 811-822.
Shelley DE . Nail dystrophy and periungual dermatitis due to cyanoacrylate glue sensiivity [letters]. J Amer Acad Derm 19(3) 574-5.
|The modified ventilated manicure table worked better than an unventilated manicure table for lowering exposures to ethyl methacrylate during artificial nail application. Personal exposures were reduced more than tenfold. Also, exposures to methyl methacrylate were well below the NIOSH recommended exposure level (REL) of 100 ppm as an 8-hour TWA.|