Researching Risk of Birth Defects Among Pregnant Nail Salon Workers and Hairdressers

Posted on by Kristen Van Buren, MPH; Miriam Siegel, DrPH, MPH; Carissa Rocheleau, PhD; and Kendra Broadwater, MPH, CIH

Workers at Risk

There are currently around 400,000 active nail technician licenses and roughly 600,000 employed hairdressers in the United States. Most of these workers are women of reproductive age, and many are foreign-born or people of color. Nail technicians often work in environments where haircare services are also provided. Nail and hair salon workers have advocated for additional research on the health hazards of their profession. A 2015 New York Times article gained national attention for nail salon workers’ health and safety when it highlighted workers’ specific concerns over hazardous workplace conditions.[1]

Nail technicians and hairdressers can be exposed to dozens of chemicals, including acrylates in artificial nail products, glues, parabens and phthalates in nail polish and hair care products, volatile organic compounds (such as toluene in hair dye and nail polish, formaldehyde in nail polishes and keratin hair treatments, and persulfates in bleach), and biocides. Some of the chemicals used by workers in nail and hair salons are associated with cancer or reproductive harm. A few studies have documented adverse birth outcomes among hairdressers, such as birth defects, small for gestational age, and miscarriage. Although previous research on nail technicians has described negative respiratory, neurological, and musculoskeletal effects, studies that address reproductive effects among this worker population are limited—and none have included birth defects.

Addressing the Issue

NIOSH researchers want to better understand adverse reproductive outcomes—birth defects in particular—among nail technicians and hairdressers. We recently analyzed data from the National Birth Defects Prevention Study (NBDPS), a large multicenter, population-based case-control study of birth defects that included mothers of infants born from 1997-2011. Job descriptions reported by mothers that participated in NBDPS were used to identify hairdressers, nail technicians, and non-cosmetologists during early pregnancy (defined as the period from one month before conception through the third month of pregnancy). We compared proportions of mothers working as nail technicians or hairdressers to those working as non-cosmetologists among children born with and without birth defects. A total study population of 43,106 mothers who reported working during pregnancy (31,541 cases and 11,565 controls) were analyzed. Of these participant mothers, 61 reported work as a nail technician, 196 reported work as a hairdresser, 39 reported work as both, and 42,810 reported working as a non-cosmetologist. Based on sample size, we analyzed eight birth defect groups among nail technicians and 22 among hairdressers. The results were published in June 2021 in Occupational and Environmental Medicine.

Birth Defects Among Nail Technicians and Hairdressers

Our results suggest that mothers who gave birth to infants with a congenital heart defect (including any heart defect, conotruncal defects, right ventricular outflow tract obstruction, and septal defects) were roughly 3 times more likely than mothers of infants with no birth defect to have worked as a nail technician during early pregnancy. Additionally, mothers who gave birth to infants with cleft lip with cleft palate were twice as likely as mothers of infants with no birth defect to have worked as a hairdresser during early pregnancy. We also found suggestive associations for mothers working as hairdressers and having infants born with defects of the ear (anotia and microtia) and abdominal wall (gastroschisis).

What’s Next?

This study was limited by small samples of mothers working as nail technicians and hairdressers. Nevertheless, it addresses an understudied area of research and highlights the need for more attention. Specific workplace practices or chemical exposures that might be associated with birth defects among nail technicians and hairdressers remain unclear. Further research, particularly on job tasks or chemical exposures for these working populations, will be beneficial to better understand reproductive health effects and help guide interventions among nail technicians and hairdressers.

Although the NBDPS offers a valuable opportunity to broadly examine workplace exposures and birth outcomes, research in cohorts of nail technicians and hairdressers—as well as the inclusion of occupation in existing studies of pregnancy outcomes—is warranted. CDC recently initiated the Birth Defects Study to Evaluate Pregnancy exposureS (BD-STEPS)[2], which gathers information on occupation during pregnancy. Workers in selected occupations will be asked to participate in a follow-up web survey module designed for their occupation to collect more detailed information on work exposures that might be of concern. This type of occupational follow-up can enrich the data from large population-based surveys and allow further research.

Employers, health care providers, public health officials, and nail technicians and hairdressers can work together to raise awareness of potential reproductive hazards encountered in the workplace and reduce exposures as much as possible. Prevention through Design concepts and a Hierarchy of Controls approach could help reduce exposures in nail and hair salons, and implementing NIOSH Total Worker Health programs in these settings might improve the overall health and well-being of workers and their families.

This blog has been translated into Vietnamese and Korean.


Kristen Van Buren, MPH, is an associate service fellow in the NIOSH Division of Field Studies and Engineering.

Miriam R. Siegel, DrPH, MPH, is an occupational epidemiologist in the NIOSH Division of Field Studies and Engineering.

Carissa M Rocheleau, PhD, is a reproductive occupational epidemiologist in the NIOSH Division of Field Studies and Engineering.

Kendra Broadwater, MPH, CIH is a research industrial hygienist in the NIOSH Western States Division.

Additional Resources

Nail Technicians’ Health and Workplace Exposure Control

Nail Files: A Study of Nail Salon Workers and Industry in the United States

Maternal occupation as a nail technician or hairdresser during pregnancy and birth defects, National Birth Defects Prevention Study, 1997-2011



[1] Maslin Nir S. Perfect Nails, Poisoned Workers. The New York Times, 2015. Available:

[2] Centers for Disease Control & Prevention. Birth Defects Study to Evaluate Pregnancy exposureS (BD-STEPS), 2020. Available:


Posted on by Kristen Van Buren, MPH; Miriam Siegel, DrPH, MPH; Carissa Rocheleau, PhD; and Kendra Broadwater, MPH, CIH

3 comments on “Researching Risk of Birth Defects Among Pregnant Nail Salon Workers and Hairdressers”

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    Given their exposure to chemical carcinogens, how is that being addressed? What ventillation controls are recommended?

    Thank you very much for your question. Both the Occupational Safety and Health Administration (OSHA), as well as the National Institute for Occupational Safety and Health (NIOSH), have online resources that further detail the types of hazardous chemicals (including carcinogens) that nail and hair salon workers may encounter and steps to prevent exposures and protect worker health (including recommended ventilation controls). Links to these detailed resources can be found below:
    Health Hazards in Nail Salons – Chemical Hazards

    Nail Technicians’ Health & Workplace Exposure Control
    Controlling Chemical Hazards During the Application of Artificial Fingernails

    Regarding your question on ventilation, there are several types of engineering controls that can help protect nail and hair salon workers from chemical exposures. These include downdraft ventilated tables, portable source capture exhaust ventilation, and ventilation systems that remove contaminants before they enter the breathing zone. NIOSH laboratory tests indicate that exhaust ventilation systems may reduce worker chemical exposure in nail salons by at least 50%.

    These facilities should be treated like paint shops or print shops rather than retail stores.
    You do have to laugh at OSHA’s suggestion to open windows. That may work in some parts of the country, but nowhere near OSHA Headquarters in downtown DC. It suggests a contractor working remotely writes these documents.

    See NIOSH –An Evaluation of Local Exhaust Ventilation Systems for Controlling Hazardous Exposures in Nail Salons

    Downdraft ventilation into the tables and through a filtering system would be the best way to draw the toxic fumes away from people in the room, consistent with paint shop technology. See Example of a Nail Salon Blueprint at [submitter has no connection of any type with aerovexsystems, but saw it as a useful source.]

    Fans are likely to blow the toxic chemicals into someone’s breathing zone and simply spread the chemicals around the room unless the room has substantial ventilation. Furthermore, the typical room ventilation is likely to draw chemicals past the breathing zone of one or more occupants. Having walked into or simply stuck my head into a number of nail salons over the years, and quickly gotten a headache and sometimes a sick feeling in a matter of 5 to 10 minutes, it seems appropriate to say many are inadequately ventilated. It is likely that many shops are simply built out or retrofitted into spec retail locations or previously occupied retail locations (malls or strip shopping centers) where the ventilation systems were not designed for the equivalent of a print shop or a paint shop.

    See Evaluation of Ergonomics, Chemical Exposures, and Ventilation at Four Nail Salons
    HHE Report No. 2015-0139-3338 March 2019
    See Excerpt from

    The International Mechanical Code (IMC) also addresses ventilation and is the basis for most state-specific mechanical codes (generally enforced by local building departments), so in many places salons must comply with its requirements for construction permits and/or certificates of occupancy. Updated every three years, the IMC has addressed nail salon ventilation since 2006. But, as it was only mentioned in a footnote, many inspectors overlooked it.

    The 2012 IMC raises the bar on salon ventilation, stating that nail stations in nail salons must now each be provided with a source-capture system capable of exhausting not less than 50 cubic-feet-per-minute. Of course, it remains to be seen which jurisdictions will enforce the code. Benjamin Bell, whose company [name removed] handles the design for a nail salon chain says the company chooses to be proactive in complying with the IMC: “Because of the sheer number of salons we have designed in locations all over the country, we have been made aware of the code requirements by multiple jurisdictions. As we ran into the concern more frequently, we did some thorough research into the issues, including discussing them with the International Code Council (the group that issues the IMC), and devised a series of stepped responses that address the concerns.” He adds that all jurisdictions that opt to enforce the 2012 code are likely to require the use of vented tables. “We have also begun to see some jurisdictions that require source capture at the pedicure spas as well,” Bell says. [A nail supply company] even released a pedicure spa, [model name removed], that features two vents to meet the IMC requirements.)

    State cosmetology boards also hold some jurisdiction over salon air quality. However, many boards use vague undefined terms like “adequate” when describing the requirements for a ventilation system, which isn’t really enforceable.

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Page last reviewed: March 21, 2022
Page last updated: March 21, 2022