Health Hazard Evaluation Report 2017-0006-3319 Page 1

Characterizing Exposures During Laser Tattoo 

Removal in a Hospital Dermatology Center

HHE Report No. 2017-0006-3319

May 2018

Revised August 2019

Michael P. Grant, ScD

Eric Glassford, MS, CIH

Brett J. Green, PhD

Angela R. Lemons, MS
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Contents

Highlights...............................................i

Abbreviations ..................................... iii

Introduction......................................... 1

Methods ............................................... 2

Results and Discussion ....................... 4

Conclusions........................................ 16

Recommendations............................. 16

Appendix A ........................................ 18

Appendix B ......................................... 22

Appendix C ......................................... 23

Appendix D ........................................ 24

Appendix E ......................................... 25

Appendix F ......................................... 27

References .......................................... 34

Acknowledgements........................... 37

The employer is required to post a copy of this report for 30 days at or near the 

workplace(s) of affected employees. The employer must take steps to ensure 

that the posted report is not altered, defaced, or covered by other material.

The cover photo is a close-up image of sorbent tubes, which are used by the HHE 

Program to measure airborne exposures. This photo is an artistic representation that may 

not be related to this Health Hazard Evaluation. Photo by NIOSH.

Revision Summary: The original final report omitted Table A2 from Appendix A. The 

revised report corrects this omission and now includes Table A2 - Table of target 

analytes for metals in air samples during tattoo removal (in μg/m3)
Health Hazard Evaluation Report 2017-0006-3319 Page i

We evaluated exposures to 

dermatologists during laser 

tattoo removal at a hospital 

dermatology center. We found 

low levels of some metals, 

volatile organic compounds, 

bacteria, and particles in our 

air samples. We recommend 

that the laser safety program 

be strengthened with accurate 

use of the “laser in use” signs, 

replacing damaged laser 

protective eyewear, and 

contacting the manufacturer 

to establish shelf lives and best 

practices for cleaning and care.

Highlights of this Evaluation

The Health Hazard Evaluation Program received a request from a hospital dermatology center. 

The employer was concerned about exposures to the plume produced during laser tattoo removals.

What We Did

● We evaluated the center in December 2016, February 2017, and July 2017.

● We measured exposures to particles, volatile organic compounds, metals, carbon monoxide, 

hydrogen sulfide, and bacteria during tattoo removal from both pig skin and patients.

● We asked employees about practices surrounding “laser in use” signs; training practices; 

and policies surrounding cleaning, storage, and replacing laser protective eyewear.

What We Found

● Concentrations of metals in personal air samples 

were all below occupational exposure limits.

● Low levels of acetone, isopropyl alcohol, and 

xylene in were measured in air samples.

● Particle concentrations were higher in the air 

around the dermatologist and close to the laser 

tattoo process as compared to other areas within 

the patient room.

● Laser tattoo emissions did not migrate out of the 

patient room.

● We did not detect carbon monoxide or hydrogen 

sulfide at any time during the tattoo removals.

● Laser eyewear needed replacing. 

● Improper use of the “laser in use” signs could 

lead to accidental eye exposures.

What the Employer Can Do 

● Work with your Department of Environmental 

Health and Safety to ensure compliance with the voluntary respiratory protection 

program standard if voluntary use respirators are provided. 

● Contact the manufacturers of the different lasers to establish shelf life, storage 

conditions, and appropriate cleaning methods for laser safety eyewear.

What Employees Can Do

● Discontinue use of the laser and molded surgical masks for respiratory protection.

● Only use respirators certified by the National Institute for Occupational Safety and Health.

● Operate the “laser in use” signs only when the laser is in use.

● Report damaged or worn laser protective eyewear to your supervisor.
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Health Hazard Evaluation Report 2017-0006-3319 Page iii

Abbreviations

μg/m3 Micrograms per cubic meter

ACGIH® American Conference of Governmental Industrial Hygienists

CFR Code of Federal Regulations

CPC Condensation particle counter

DNA Deoxyribonucleic acid

LPE Laser protective eyewear

ND Not detected

nm Nanometer

NIOSH National Institute for Occupational Safety and Health

OEL Occupational exposure limit

OSHA Occupational Safety and Health Administration

p/cc Particles per cubic centimeter

PCR Polymerase chain reaction

ppb Parts per billion

PPE Personal protective equipment

rDNA Ribosomal deoxyribonucleic acid

TLV® Threshold limit value

VOC Volatile organic compound
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Health Hazard Evaluation Report 2017-0006-3319 Page 1

Introduction

The Health Hazard Evaluation Program received a request from the manager of a 

dermatology center at a hospital in Massachusetts. The employer was concerned about 

dermatologist’s exposures to the plume created during laser tattoo removal. We visited the 

center in December 2016, February 2017, and July 2017 to assess exposures to metals, 

volatile organic compounds (VOCs), particles, bacteria, carbon monoxide, and hydrogen 

sulfide. We also observed work practices and airflow patterns. 

Background

We visited the center on three different occasions to observe work practices and perform 

environmental sampling during laser tattoo removal. In February 2017, we assessed 

exposures to a dermatologist performing laser tattoo removal from slabs of pig skin. This 

is a routine activity of the position, as dermatologists use this method to practice removing 

tattoos, and to test new lasers and techniques. Tattoo removal using pig skin provides a 

similar experience to removing tattoos from human skin. As the dermatologists first tattoo the 

pig skin, it also allows for the knowledge of exactly which ink was in the tattoo. Ink type is 

not typically known when tattoo removal occurs in human patients. In July 2017, we assessed 

exposures to a dermatologist performing laser tattoo removal from patients.

The laser tattoo removal process generally requires multiple treatments after an initial 

consultation. Each treatment removes some of the ink particles in the skin. Treatments are 

typically at least two weeks apart from each other to allow the skin to heal before the next laser 

application. The duration of a laser tattoo removal depends on the size of the tattoo. Smaller 

tattoo removals last only a few minutes while larger tattoos could take 30–45 minutes. After the 

procedure, the dermatologist cleaned the tattoo with isopropyl alcohol and applied a cream. The 

laser tattoo removals are performed in a generic patient examination room. The examination 

room has an adjustable chair for the patient to sit in and an overhead light (Figure 1). The laser 

tattoo removal machines are portable and can be wheeled into the appropriate examination 

room to the side of an adjustable examination chair for easy patient access. Multiple laser 

machines were used, depending on the wavelength and power of the laser desired. The laser 

machines were operated at various pulse rates and wavelengths. The machines used either 

specific pulse rates (picosecond or nanosecond) or variable pulse rates (q-switched). Laser 

wavelengths used included 532 nanometer (nm), 694 nm, 755 nm, or 1,064 nm wavelengths. 

The color of the tattoo was a primary factor in the choice of pulse rate and wavelength. 

Different colored ink and skin tones react differently to specific wavelengths. 
Page 2 Health Hazard Evaluation Report 2017-0006-3319

Figure 1. Dermatologist using a laser probe to remove a tattoo. Photo by NIOSH.

Typically, patients will schedule a consultation with a dermatologist in order to explore tattoo 

removal options. If the patient is eligible for a removal and decides to undergo the procedure, 

the procedure is performed on the same day unless there are scheduling conflicts with the 

patient. This clinic can perform anywhere from one to five tattoo removals on an average day. 

The exact number can vary considerably depending on how many patients are seeking tattoo 

removals. Dermatologists perform other procedures during the day, not just tattoo removals.

The employer was concerned about the contents of the plume produced during laser tattoo

removal. We evaluated exposures to metals, VOCs, particles, carbon monoxide, hydrogen sulfide,

and bacteria. We chose these targets for assessment because they were the most likely components

of the plume produced during laser tattoo removal. It is known that tattoo inks often contain

metals [Forte et al. 2009]. The action of using a laser to enter the skin and heat up ink particles has

a high likelihood of producing VOCs by burning skin, hair, and ink components. When a laser is

applied to tattoo ink, the laser targets the ink particles and either breaks them down into smaller

particles or expels them from the skin [Ho et al. 2002]. Carbon monoxide has been detected in

the plume produced during laser hair removal, which is a similar skin and hair burning process

to tattoo removal [Chuang et al. 2016]. Hydrogen sulfide can interfere with carbon monoxide

measurements so we measured for both substances simultaneously. Bacterial genetic material has

been identified in smoke plumes from other types of laser treatments [Sawchuck et al. 1989].

Methods

The objective of this project was to characterize the plume produced during laser tattoo 

removals. To accomplish this objective we assessed exposures to (1) metals, (2) VOCs, 

(3) particulates, (4) bacteria, (5) carbon monoxide, and (6) hydrogen sulfide.

In order to account for the variable frequency of tattoo removals on any given day, the clinic 

had scheduled multiple consecutive patient tattoo removals to happen after the clinic was 

closed. There were no tattoo removals performed during the normal business hours of the clinic.
Health Hazard Evaluation Report 2017-0006-3319 Page 3

We had three main sampling locations: (1) air samples collected in or near the breathing 

zone of the dermatologist performing the tattoo removals; (2) area air samples collected in 

the patient room near where an attendant (an additional dermatologist or nurse) would be 

located during tattoo removal procedures; and (3) area air samples collected at an employee 

workstation outside of the patient room to determine if the emissions could migrate. These 

sampling locations were the same for all exposures that were assessed.

Metals

Prior to our arrival in February 2017, the dermatologist tattooed five slabs of pig skin with 

different ink colors. We took bulk samples of each of the tattoo inks used and analyzed them for 

metals according to National Institute for Occupational Safety and Health (NIOSH) Method 7303 

[NIOSH 2018]. A list of target analytes for the bulk sample analysis is in Appendix A, Table A1. 

We collected personal air samples for metals in the breathing zone of the dermatologist 

performing tattoo removals from pig skin (February 2017) and from actual patients (July 

2017). We analyzed the air samples for metals according to NIOSH Method 7303 [NIOSH 

2018]. Lists of target analytes for the air sample analyses are in Appendix A, Table A2.

Volatile Organic Compounds

We collected area air samples using 1.4 liter evacuated canisters and analyzed them according 

to Environmental Protection Agency method TO-15 [EPA 1999]. These area air samples were 

collected both inside and outside of the patient room during the entire removal process, for each 

type of tattoo removal. Instantaneous samples for each type of tattoo removal were collected 

directly above the laser probe, while the tattoo was being removed. The flow controllers 

used for area air sampling were designed for a 2 hour (pig skin removals) and 4 hour (patient 

removals) sampling duration. The flow controllers for instantaneous sampling were designed 

for a short sampling duration (less than 30 seconds). Lists of the 65 target analytes are in 

Appendix A, Table A3. Additional compounds were tentatively identified using the Wiley 

Registry 9th edition/National Institute of Standards and Technology 2008 mass spectral library.

Particulate Air Sampling

We used direct-reading instruments to measure airborne particulate in real time during the 

tattoo removals. We used a TSI® model 3007 handheld condensation particle counter (CPC) 

to measure ultrafine particle number concentrations and a TSI SidePak Personal Aerosol 

Monitor (SidePak) to measure particulate mass concentrations. In addition to the area 

samples, we used another CPC to measure particle number concentrations closer to the tattoo 

removal process, where the dermatologist was positioned. The inlet was positioned in the 

breathing zone of the dermatologist. 

We also collected personal samples of respirable particulate mass concentrations during the 

tattoo removal process. We placed a SidePak attached to a cyclone sampler in the breathing 

zone of the dermatologist during the tattoo removal to evaluate personal exposure to the 

respirable mass concentrations. Respirable particles are those that can reach the alveolar 

region (deepest region) of the lung when inhaled.
Page 4 Health Hazard Evaluation Report 2017-0006-3319

Bacterial Exposures

During laser tattoo removals from patients, we used a NIOSH two-stage bioaerosol sampler 

[Lindsley et al. 2006]. We collected personal and area air samples during the tattoo removals 

from patients. Further details of the sampling and microbiological diversity analysis are in 

Appendix B. Briefly, we used deoxyribonucleic acid (DNA) to identify varieties of bacteria 

by comparing our sequence results to the National Center for Biotechnology Information 

database. We did not measure bacterial exposures during laser tattoo removals from pig skin.

Carbon Monoxide and Hydrogen Sulfide

We took area and personal measurements using BW Honeywell, GasAlert Extreme single gas 

monitors to measure carbon monoxide and hydrogen sulfide during the tattoo removals. 

Results and Discussion

During our visit in February 2017, the dermatologist removed tattoos from five slabs of pig 

skin. Each slab was tattooed using a different, known color and brand of ink. The removal 

time ranged from one to eight minutes. During each removal, the laser was operated at a 

specific wavelength and pulse rate (Appendix C, Table C1). During our visit in July 2017, 

the dermatologist removed 6 tattoos from 5 patients over two days. The removal time ranged 

from 3 to 19 minutes depending on the size of the tattoo. Some patients had tattoos with 

multiple colors or had multiple tattoos being removed. The wavelength and pulse rate used 

depended on the colors of the tattoo (Appendix C, Table C2). 

Metals

Laser Tattoo Removal from Pig Skin

The results of the metals analysis for the bulk tattoo ink samples are presented in Appendix 

D, Table D1. All inks tested had detectable amounts of metals in them. 

The task-based personal air samples had low levels of aluminum, copper, manganese, 

phosphorus, potassium, titanium, and zirconium (Table 1). If the dermatologist were to perform 

this task for a full day, then they would be well below the lowest occupational exposure limits 

(OELs) for each analyte set by the Occupational Safety and Health Administration (OSHA), 

NIOSH, and the American Conference of Governmental Industrial Hygienists (ACGIH). For 

more information about OELs, refer to Appendix E. We found magnesium and potassium in 

the area air sample collected in the patient room. Potassium does not have an OEL. We found 

titanium in the area air sample from an employee workstation outside the patient room. Other 

metals were not detected. OSHA, NIOSH, and ACGIH do not have OELs for area air samples. 
Health Hazard Evaluation Report 2017-0006-3319 Page 5

Table 1. Air samples for elements while the dermatologist is performing tattoo removals from 

pig skin (in μg/m3)*†

Analyte Breathing zone‡ Area inside patient room§ Waiting room¶

Aluminum [1.1] ND ND

Copper [0.27] ND ND

Manganese [0.04] [5.0] ND

Phosphorus [1.3] ND ND

Potassium [2.0] [0.82] ND

Titanium** [0.61] ND 0.47

Zirconium [0.06] ND ND

[ ] = Estimated concentration; this concentration was between the minimum detectable 

concentration and the minimum quantifiable concentration.

μg/m3

 = Micrograms per cubic meter

ND = Not detected

*The minimum detectable and quantifiable concentrations are listed in Appendix A, Table A2.

†The duration of these samples were 91–96 minutes.

‡Personal breathing zone samples taken within the breathing zone of the dermatologist.

§Area air samples for elements in the patient room near where an attendant would be located.

¶Area air sample from an employee workstation outside the patient room.

**As titanium dioxide

Laser Tattoo Removal from Patients

The personal air samples collected from patients contained low levels of manganese, 

potassium, and zinc (Table 2). If the dermatologist were to perform this task for a full day, 

then they would be well below the lowest OELs for each analyte set by OSHA, NIOSH, 

and ACGIH. For more information about OELs, refer to Appendix E. We found beryllium, 

potassium, vanadium, and zinc in the area air sample collected in the patient room near where 

an attendant would be located. We found lithium and potassium in the area air sample from 

an employee workstation outside the patient room. Other metals were not detected. 
Page 6 Health Hazard Evaluation Report 2017-0006-3319

Table 2. Air samples for elements while the dermatologist is performing tattoo removals 

from patients (in μg/m3)*†

Analyte Breathing zone‡ Area inside patient room§ Waiting room¶

Day 1

Lithium

Potassium

Beryllium

Vanadium

Zinc**

Day 2

Manganese

Potassium

Zinc**

ND

5.3

ND

ND

ND

[0.22]

8.2

[0.56]

ND

ND

[0.01]

[0.43]

[0.51]

ND

8.4

ND

[0.07]

4.9

ND

ND

ND

ND

7.6

ND

[ ] = Estimated concentration; this concentration was between the minimum detectable 

concentration and the minimum quantifiable concentration.

*The minimum detectable and quantifiable concentrations are listed in Appendix A, Table A2.

†The duration of these samples were 91–93 minutes on day one and 47–50 minutes on day two.

‡Personal breathing zone samples taken within the breathing zone of the dermatologist.

§Area air samples for elements in the patient room near where an attendant would be located.

¶Area air sample from an employee workstation outside the patient room.

**As titanium dioxide

Overall, there were fewer metals detected in the air samples taken during tattoo removals 

from patients, than from pig skin. This may be due to the natural processes whereby the 

immune system attacks tattoo pigment particles [Grant et al. 2015]. Over time, this allows 

the tattoo to become more “permanent” as any particles that were small enough to be 

removed through natural processes have been excreted. The remaining pigment particles are 

more difficult to remove from the skin, even when using a laser. Since the pig skin tattoos 

were applied to dead skin, there is no immune system response to begin the process of 

removing pigment particles. Thus, it is not surprising to see more metal particles in the air 

when the ink was removed from the pig skin compared to patients where the tattoos were 

much older and applied to living tissue. Regardless, concentrations seen in both removal 

scenarios were below established OELs. 

Volatile Organic Compounds

Laser Tattoo Removal from Pig Skin

To assess VOCs in the air, we collected three area samples (approximately 90 minutes each) 

and nine instantaneous samples (approximately 30 seconds each). We found several 

detectable but not quantifiable VOCs in the area air samples collected (Table 3). We found 

quantifiable, but low levels of several VOCs including isopropyl alcohol, acetone, propene, 

ethyl acetate, and toluene. 
Health Hazard Evaluation Report 2017-0006-3319 Page 7

We found VOCs in all but one of the instantaneous samples collected. The type and number 

of compounds detected varied depending on the wavelength of the laser and color of the ink 

in the tattoo. See Appendix F, tables F1–F5 for more details. In addition to the VOCs listed in 

the tables, 51 other chemicals were tentatively identified in the canister air samples. 

Table 3. Air samples for VOCs while the dermatologist is performing tattoo removal from 

pig skin (in ppb)*†

Analyte Area near 

breathing zone‡

Area inside 

patient room§

Waiting room¶

1,2,4-Trimethylbenzene ND [0.12] [0.19]

2,2,4-Trimethylpentane ND [0.24] [0.35]

2-Butanone ND [0.49] [0.78]

Acetone 26 21 18

Benzene [0.57] [0.51] [0.59]

Carbon disulfide ND ND [0.21]

Chloromethane [0.73] [0.69] [0.66]

Dichlorodifluoromethane [0.52] [0.53] [0.52]

Ethyl acetate [0.18] [0.16] 1.6

Ethylbenzene [0.18] [0.22] [0.59]

Heptane ND [0.12] [0.40]

Hexane [0.20] [0.22] ND

Isopropyl alcohol 9,600 2,000 14,000

m & p-Xylene [0.57] [0.65] [1.9]

Methylene chloride [0.30] [0.26] [0.28]

o-Xylene [0.20] [0.22] [0.54]

Propene 1.7 1.8 2.0

Toluene [0.75] [0.77] 1.2

Trichlorofluoromethane [0.68] [0.65] [0.64]

[ ] = Estimated concentration; this concentration was between the minimum detectable 

concentration and the minimum quantifiable concentration.

ppb = Parts per billion

*The minimum detectable and quantifiable concentrations are listed in Appendix A, Table A3.

†The duration of these samples were 89–92 minutes.

‡Personal breathing zone samples taken within the breathing zone of the dermatologist.

§Area air samples for elements in the patient room near where an attendant would be located.

¶Area air sample from an employee workstation outside the patient room.
Page 8 Health Hazard Evaluation Report 2017-0006-3319

Laser Tattoo Removal from Patients

We took six area samples during the entire removal process and nine instantaneous samples. 

We found low levels of several VOCs in the area air samples collected including acetone, 

ethylbenzene, isopropyl alcohol, and m & p-xylene (Table 4). 

We found VOCs in all of the instantaneous samples collected. The type and number of 

compounds detected varied depending on the wavelength of the laser and color of the ink 

in the tattoo. We expected to see VOCs in all of the instantaneous samples because of the 

nature of the laser tattoo removal process. Different inks and lasers produced different VOCs, 

all at very low concentrations. See Appendix F, Tables F6–F9 for more details. In addition to 

the VOCs listed in the tables, 28 other chemicals were tentatively identified in the canister 

air samples. 

Although there were some differences in the results from the area air samples between days 

one and two (Table 4), we saw similar concentrations of the same analytes on both days and 

in all locations. Black tattoos tended to have the same analytes detected in the instantaneous 

samples (see Appendix F, Table F6). Variability in the concentrations can be attributed to the 

inherent biological and physiological differences between patients. Additionally, each tattoo 

was different (i.e., age, type and density of ink, location on the body) so we would expect to 

see differing concentrations. There were also similar results for the instantaneous samples 

during removal of blue/green tattoos (see Appendix F, Table F9). The red and yellow tattoo 

removals used the same wavelength of laser so it is not surprising that there were similar 

analytes detected in each sample (see Appendix F, Tables F7 and F8). There are larger 

differences in concentrations detected in these samples compared to the comparisons of the 

black or blue/green samples. The larger variations in type and concentration of analytes 

detected in these samples is likely due to the different colored ink in addition to the 

differences between patients and tattoos mentioned above.
Health Hazard Evaluation Report 2017-0006-3319 Page 9

Table 4. Air samples for elements while the dermatologist is performing tattoo removals from 

patients (in μg/m3)*†

Analyte Breathing zone‡ Area inside patient room§ Waiting room¶

Day 1

Acetone 35 35 23

Ethyl acetate [3.4] [4.0] [4.9]

Ethylbenzene [5.7] [5.6] 13

Isopropyl alcohol 5,800 5,100 4,800

m & p-Xylene 16 16 35

o-Xylene [3.4] [3.4] 7.5

Day 2

Acetone 28 29 140

Ethyl acetate ND ND [4.5]

Ethylbenzene 23 [8.6] [9.8]

Isopropyl alcohol 3,900 4,300 4,300

m & p-Xylene 39 26 29

o-Xylene [11] [5.8] [6.8]

[ ] = Estimated concentration; this concentration was between the minimum detectable 

concentration and minimum quantifiable concentration.

*The minimum detectable and quantifiable concentrations are listed in Appendix A, Table A2.

†The duration of these samples was 90 minutes on day one and 48 minutes on day two.

‡Personal breathing zone samples taken within the breathing zone of the dermatologist.

§Area air samples for elements in the patient room near where an attendant would be located.

¶Area air sample from an employee workstation outside the patient room.

Direct-reading Particulate Air Sampling

Laser Tattoo Removal from Pig Skin

We measured peaks in particle concentrations that corresponded to the starting and stopping 

times of the tattoo removal process. Figure 2 shows the particle concentrations from CPC 

data collected in the patient room during pig skin removal where the attendant would be 

located as compared to the employee workstation outside of the patient room. Particle 

concentrations sharply increased when a tattoo removal was started. When the process was 

stopped to change laser configurations or change pig skin tattoo samples with new colors, 

the particle concentrations in the patient room declined. Information on the tattoo color, 

laser wavelength, pulse rate, and duration are provided in Appendix C, Table C1. The tattoo 

removals ranged from one to eight minutes. 
Page 10 Health Hazard Evaluation Report 2017-0006-3319

Figure 2. Particle concentration comparison between the patient room and the employee workstation 

areas, from CPC data. The dark gray line shows particle concentrations where an attendant would 

be located. The blue line represents particle concentrations at the employee workstation outside of 

the patient room. We identified 12 notable peaks that related to starting and stopping times of tattoo 

removal on pig skin.

The mean particle number concentration inside the patient room during the tattoo removal 

on pig skin was approximately 91,000 particles per cubic centimeter (p/cc), and ranged from 

48,000‒147,000 p/cc. This was several times higher than particle concentrations measured 

outside the room in the employee workstation area, which ranged from 20,000–30,000 p/cc 

during the process. The average particulate mass concentrations inside the patient room was 

61 μg/m3

, which was approximately five times higher than outside the room at the employee 

workstation (average 12 μg/m3

). Particulate mass and number concentrations measured at the 

employee workstation did not show similar peaks or fluctuations that corresponded to tattoo 

start and stop times. Therefore, we did not find any evidence indicating that tattoo emissions 

were migrating out of the patient rooms during the removal process. Personal air sampling 

for respirable particle mass concentrations during pig skin tattoo removal averaged 70 μg/m3

over the 90 minutes of sampling.

We also placed a CPC on the patient chair a few inches away from the pig skin, on the right 

side of the dermatologist. At various times during the laser tattoo removal, we moved the 

CPC to see if any changes occurred in particle concentrations based on location. When we 

moved the CPC to the left side of the dermatologist (between the tattoo being removed 
Health Hazard Evaluation Report 2017-0006-3319 Page 11

and the laser removal unit), we noticed particle concentrations increased 3–4 times when 

compared to the right side of the dermatologist (Figure 3). We believe this may have been 

from the cooling fan of the laser, which was pulling air toward the unit and was located on 

the left side of the dermatologist. 

Overall, the real-time particulate air sampling data shows that the laser tattoo process 

increased the amount of airborne particles near the dermatologist during pig skin tattoo 

removal, as compared to other locations within or outside of the room.

Figure 3. CPC data showed dramatic increases in particle concentrations from one side of the 

dermatologist compared to the other. Particle concentrations increase by 3–4 times when we 

measured on the left side of the dermatologist compared to the right side.

Laser Tattoo Removal from Patients

Personal air sampling for respirable particulate mass concentrations averaged 21 μg/m3 on 

day one over 90 minutes, and 11 μg/m3

 on day two over 45 minutes. While brief increases 

(peaks) in particulate mass concentrations occurred several times throughout the sampling 

periods, we did not see any pattern that would match the timing of the laser tattoo removals. 

We saw particle concentrations in the patient room rapidly increase with peaks when we moved 

the roaming CPC close to the tattoo removal process. Peaks occurred when we positioned the 
Page 12 Health Hazard Evaluation Report 2017-0006-3319

CPC on both sides of the dermatologist, near the dermatologist’s breathing zone, near the tattoo 

removal site, and directly above the tattoo site. These increases in particle concentrations again 

show that the area around the laser tattoo removal site has increased particle concentrations, 

including where the dermatologist is situated during the removal process. In contrast to the 

pig skin tattoo removal, we saw an increase in particle number concentrations on both sides 

of the dermatologist, not just the left side. We believe that the difference during patient tattoo 

removals could be due to the dermatologist moving around more and also that the patient’s 

body may be causing changes in the airflow direction. 

There were no observable peaks detected at the attendant location in the patient room. 

Average particle concentrations were approximately 3,000 p/cc on both days of sampling. We 

also did not see patterns in particulate mass and number concentrations in the waiting room 

area that would indicate laser tattoo removal emissions are escaping the patient room. On 

average, particulate mass and number concentrations in the employee workstation were lower 

than the patient room. 

Between the two different types of laser tattoo removal processes, we noticed that particle 

number and mass concentrations were highest near the dermatologist and the tattoo removal 

site. However, laser tattoo removal from pig skin had almost 30 times higher particle 

concentrations in the patient room compared to human tattoo removal. For both types of 

tattoo removal, particle concentrations did not seem to migrate outside of the patient room.

Bacterial Exposures during Laser Tattoo Removal from 

Patients

We collected two personal and four area air samples for bacteria. On day one, the personal air 

sample was collected for 93 minutes and the area air samples were collected for 91 minutes. 

On day two, the personal air sample was collected for 50 minutes and the area air samples 

were collected for 48 minutes. The results are reported as the relative abundance, which is 

the percentage of each bacteria phylum and class out of the total number of DNA sequences 

identified in the analysis. Bacterial clones were clustered into 27 operational taxonomic 

units. Bacterial sequences identified in the field and media negative control samples were 

subtracted from the results. A total of 5 bacterial phyla and 8 classes were identified in 

the analysis (Figure 4). The bacterial phyla identified were Actinobacteria, Bacteroidetes, 

Firmicutes, Fusobacteria, and Proteobacteria (Figure 4A). The gram-positive phylum, 

Firmicutes, was the most frequently detected phyla (41%) and consisted of sequences placed 

in the classes Bacilli (19.1%) and Clostridia (21.4%) (Figure 4B). Sequences derived from 

the Firmicutes comprised 63% and 43% of bacterial sequences identified in the employee 

workstation and personal breathing zone samples, respectively (Figure 5). Other commonly 

detected phyla were the Proteobacteria (26%) that was prevalent in patient room samples, 

whereas sequences derived from the Bacteroidetes accounted for 38% and 25% of bacterial 

sequences in employee workstation and personal breathing zone samples, respectively 

(Figure 5). OSHA, NIOSH, and ACGIH do not have OELs for bacteria.
Health Hazard Evaluation Report 2017-0006-3319 Page 13

Figure 4. Relative abundance of bacterial phylum (A) and class (B) detected in area air samples 

during laser tattoo removal, across all samples collected.
Page 14 Health Hazard Evaluation Report 2017-0006-3319

Figure 5. Relative abundance of five bacterial phylum detected in each of the three 

sampling locations.

Actinobacteria, Fusobacteria, and Proteobacteria were found in the air samples taken in the 

patient examination room, but not in the air samples taken at the employee workstation. 

Actinobacteria are commonly found on the skin [Grice and Segre 2011]. Fusobacteria 

are commonly associated with topical skin ulcers and the normal flora of the oropharynx 

[Riordan 2007]. Although the dermatologist did not note topical skin ulcers, it is possible 

that they were not detected during the intake examination. Proteobacteria have been found 

to be the dominant microbe in human skin [Grice et al. 2008]. Detecting these phyla in the 

patient room but not outside of the patient room could indicate that they were present due to 

the laser tattoo removals. It is also possible that these phyla were detected because there were 

more people inside the patient room than outside the room. Bacteroidetes and Firmicutes 

are widely found in the environment and are common gut flora [Grice and Segre 2011]. It is 

not surprising to find Bacteroidetes and Firmicutes in the area air samples at the employee 

workstation outside of the patient room and not inside of the patient room. The patient room 

is cleaned more thoroughly and frequently than the other areas of the clinic. 

Carbon Monoxide and Hydrogen Sulfide

We did not detect carbon monoxide or hydrogen sulfide at any time during the tattoo 

removals from pig skin or patients. We sampled for both gases over the entire duration of 

the tattoo removal activities (approximately 90 minutes on day one and approximately 

45 minutes on day two). 
Health Hazard Evaluation Report 2017-0006-3319 Page 15

Workplace Observations

During our visits, we made observations related to employees’ use of personal protective 

equipment (PPE), laser safety practices, and room pressurization. When performing laser 

tattoo removals, dermatologists wore nitrile gloves, a molded surgical mask (Figure 1), 

and laser protective eyewear (LPE). Employees reported that the manufacturer of the laser 

provided all LPE to the center. The center also had laser masks available for voluntary 

wear. The laser masks were different from the molded surgical masks and were marketed as 

protective against plumes during laser surgery, but they were not NIOSH-certified respirators. 

We learned that employees voluntarily wore the laser masks during hair removal procedures 

and that the decision whether to wear them was made by the employee. There was no 

mandatory respiratory protection program for the clinic. 

All LPE was stored in plastic bins in the same room as the laser they were intended to 

protect against. It was difficult to read optical density and wavelength on some pairs of LPE. 

Therefore, employees may not be able to confirm whether the worn LPE will protect against 

the wavelengths. Each patient examination room was labeled with appropriate signage and 

had an operational “laser in use” sign. These signs were illuminated (turned on) for the 

entire work shift, even when the laser was not in use. Employees relied on knocking and 

listening to determine whether to enter the examination room. Leaving the signs illuminated 

throughout the work day defeats the purpose of the signs. Entering an examination room 

without appropriate LPE can increase the risk of eyes being exposed to lasers. Keeping 

worn LPE in the workplace without knowing the shelf life could also increase the chances 

of inadvertent eye exposures, as the effectiveness of LPE decreases over time. All laser 

machines were independently labeled as inspected annually by the hospital.

We observed that the examination rooms were negative pressurized relative to the hallway, 

using ventilation smoke tubes. This means that air flowed from the hallway and into the 

examination room. The negative pressure airflow is in agreement with our findings for 

metals, VOC’s, and particles. We did not observe any evidence that the emissions from the 

laser tattoo removals were migrating out of the patient exam rooms. 

We observed a dermatologist using a smoke evacuator during laser hair removal procedures 

(Figure 6). The workplace has two types of smoke evacuators that use the same kind of filter. 

The filter has four stages: (1) pre-filter for larger particles; (2) an ultra-low penetration air 

filter; (3) activated carbon bed; and (4) a foam section that prevents activated carbon particles 

from migrating out of the filter. There is a lighted display that indicates filter life and suction 

power. The suction tube is held next to the laser probe during the procedures. Dermatologists 

reported that one of the major benefits to using the smoke evacuators during laser hair 

removal was that it helped to control odors during hair removal procedures. Although this 

health hazard evaluation request was not focused on hair removal, employees questioned 

whether the smoke evacuators were necessary during tattoo removals.
Page 16 Health Hazard Evaluation Report 2017-0006-3319

Figure 6. One of the smoke evacuators used during laser hair removal. They are located in the same 

rooms that the laser tattoo removals occur.

Conclusions

We evaluated exposures associated with laser tattoo removal at a hospital dermatology center. 

Although we were able to measure low levels of some metals, VOCs, bacteria, and particles, 

none of our results were above applicable OELs. Our results do not indicate that respiratory 

protection is required. We observed that the laser safety program could be strengthened to 

include replacing LPE when it has become worn out and new practices around the “laser in 

use” signs. We also observed that the voluntary use masks available to employees were not 

certified by NIOSH. 

Recommendations 

On the basis of our findings, we recommend the actions listed below. We encourage the 

dermatology center to use a labor-management health and safety committee or working group 

to discuss our recommendations and develop an action plan. Those involved in the work can 

best set priorities and assess the feasibility of our recommendations for the specific situation 

at the office. 

Our recommendations are based on an approach known as the hierarchy of controls 

(Appendix E). This approach groups actions by their likely effectiveness in reducing or 

removing hazards. In most cases, the preferred approach is to eliminate hazardous materials 

or processes and install engineering controls to reduce exposure or shield employees. Until 

such controls are in place, or if they are not effective or feasible, administrative measures and 

PPE may be needed. 
Health Hazard Evaluation Report 2017-0006-3319 Page 17

Administrative Controls

The term administrative controls refers to employer-dictated work practices and policies 

to reduce or prevent hazardous exposures. Their effectiveness depends on employer 

commitment and employee acceptance. Regular monitoring and reinforcement are necessary 

to ensure that policies and procedures are followed consistently.

1. Contact the manufacturers of the different lasers in the center to establish shelf life, 

storage conditions, and appropriate cleaning methods for laser safety eyewear as 

described in the American National Standards Institute (ANSI) standard Z136.3 

Section 4.6.2.

2. Utilize the signs indicating “laser in use” only when lasers are being used.

3. Use smoke evacuators to help control nuisance odors. Use the existing smoke 

evacuators in a manner consistent with how it is used during laser hair removal. 

Personal Protective Equipment

PPE is the least effective means for controlling hazardous exposures. Proper use of 

PPE requires a comprehensive program and a high level of employee involvement and 

commitment. The right PPE must be chosen for each hazard. Supporting programs such as 

training, change-out schedules, and medical assessment may be needed. PPE should not 

be the sole method for controlling hazardous exposures. Rather, PPE should be used until 

effective engineering and administrative controls are in place.

1. Discontinue use of the laser masks and molded surgical masks for respiratory 

protection. If employees want to use respirators on a voluntary use basis, use NIOSHapproved filtering facepiece respirators (such as an N95).

2. Contact your Department of Environmental Health and Safety to ensure that you are 

in compliance with the voluntary use provisions of the OSHA respiratory protection 

standard (29 CFR 1910.134) if you plan to wear filtering facepiece respirators during 

tattoo removal. We found no evidence that respiratory protection should be required.

3. Ensure that all LPE is clearly labeled with the optical density and wavelength that the 

eyewear protects against as described in ANSI standard Z163.3 Section 4.6.2.3. Any 

eyewear with faded or missing information should be discarded.

4. Only purchase and provide respirators certified by NIOSH. The list of NIOSHapproved N95 respirators can be found here: 

https://www.cdc.gov/niosh/npptl/topics/respirators/disp_part/n95list1.html.
Page 18 Health Hazard Evaluation Report 2017-0006-3319

Appendix A: Target Analytes and Minimum 

Detectable and Quantifiable Concentrations

Table A1. Table of target analytes for bulk ink analysis 

(milligrams per kilogram of ink)

Analyte Minimum detectable 

concentration*

Minimum quantifiable 

concentration*

Aluminum 5 15

Antimony 5 14

Arsenic 5 16

Barium 2 —

Beryllium 0.06 0.18

Cadmium 0.2 0.77

Calcium 20 74

Chromium 0.3 1.0

Cobalt 0.6 1.8

Copper 0.3 0.85

Iron 9 37

Lanthanum 0.3 1.0

Lead 6 —

Lithium 0.4 1.3

Magnesium 0.8 2.8

Manganese 0.6 2.0

Molybdenum 0.6 2.1

Nickel 0.7 2.6

Phosphorus 40 120

Potassium 0.9 3.8

Selenium 9 36

Silver 0.5 —

Strontium 0.09 0.31

Tellurium 3 9.3

Thallium 2 7.0

Tin 30 81

Titanium 0.9 3.9

Vanadium 0.5 1.5

Yttrium 0.03 0.093

Zinc 9 31

Zirconium 0.09 0.30

*These values varied slightly from sample to sample. 

The most conservative numbers are listed here.
Health Hazard Evaluation Report 2017-0006-3319 Page 19

Table A2. Table of target analytes for metals in air samples 

during tattoo removal (in μg/m3)

Analyte Minimum detectable 

concentration*

Minimum quantifiable 

concentration*

Aluminum 0.8–2 2.8–5.2

Antimony 0.2–3 4.5–8.4

Arsenic 0.2–2 2.9–7.9

Barium 0.2–0.4 0.51–1.2

Beryllium 0.01–0.02 0.03–0.05

Cadmium 0.03–0.1 0.11–0.20

Calcium 30–50 93–190

Chromium 0.3–0.5 0.85–2.2

Cobalt 0.1–0.3 0.32–1.1

Copper 0.2–0.5 0.64–1.5

Iron 2–10 8.5–26

Lanthanum 0.02–0.1 0.08–0.35

Lead 0.5–2 1.7–5.0

Lithium 0.06–0.3 0.17–0.90

Magnesium 5–10 19–38

Manganese 0.03–0.2 0.11–0.73

Molybdenum 0.1–0.4 0.45–1.3

Nickel 0.1–0.3 0.35–0.89

Phosphorus 0.8–2 2.5–53

Potassium 0.8–2 2.7–5.2

Selenium 3–10 8.5–33

Silver 0.05–0.1 0.20–0.39

Strontium 0.1–0.2 0.34–0.63

Tellurium 0.8–3 2.9–7.9

Thallium 2–5 5.6–16

Tin 0.8–2 2.6–5.2

Titanium 0.1–0.2 0.34–0.72

Vanadium 0.3–0.5 1.3–2.4

Yttrium 0.01–0.04 0.03–0.13

Zinc 0.3–0.5 1.0–2.3

Zirconium 0.03–0.1 0.09–0.17

*These values varied slightly from sample to sample. 

The most conservative numbers are listed here.
Page 20 Health Hazard Evaluation Report 2017-0006-3319

Table A3. Table of target analytes for VOCs in air samples during tattoo removal from 

pig skin (in ppb)

Analyte Minimum detectable 

concentration*

Minimum quantifiable 

concentration*

1,1,1-Trichloroethane 0.08–4 1.2–15

1,1,2,2-Tetrachloroethane 0.2–4 1.2–15

1,1,2-Trichloroethane 0.1–4 1.2–15

1,1-Dichloroethane 0.1–4 1.2–15

1,1-Dichloroethene 0.1–4 1.2–15

1,2,4-Trichlorobenzene 0.4–4 1.2–15

1,2,4-Trimethylbenzene 0.1–4 1.2–15

1,2-Dibromoethane 0.09–4 1.2–15

1,2-Dichlorobenzene 0.2–4 1.2–15

1,2-Dichloroethane 0.1–4 1.2–15

1,2-Dichloropropane 0.08–4 1.2–15

1,3,5-Trimethylbenzene 0.2–4 1.2–15

1,3-Butadiene 0.6–4 1.2–15

1,3-Dichlorobenzene 0.1–4 1.2–15

1,4-Dichlorobenzene 0.2–4 1.2–15

1,4-Dioxane 0.2–4 1.2–15

2,2,4-Trimethylpentane 0.05–4 1.2–15

2-Butanone 0.1–4 1.2–15

2-Hexanone 0.1–4 1.2–15

4-Ethyltoluene 0.2–4 1.2–15

4-Methyl-2-pentanone 0.1–4 1.2–15

Acetone 0.7–4 1.2–15

Allyl chloride 0.1–4 1.2–15

Benzene 0.09–4 1.2–15

Benzyl chloride 0.07–4 1.2–15

Bromodichloromethane 0.1–4 1.2–15

Bromoethene 0.6–4 1.2–15

Bromoform 0.1–4 1.2–15

Bromomethane 0.4–4 1.2–15

Carbon disulfide 0.1–4 1.2–15

Carbon tetrachloride 0.07–4 1.2–15

Chlorobenzene 0.1–4 1.2–15

Chloroethane 0.6–4 1.2–15

Chloroform 0.08–4 1.2–15

Chloromethane 0.2–4 1.2–15

cis-1,2-dichloroethene 0.08–4 1.2–15

cis-1,3-dichloropropene 0.2–4 1.2–15

Cyclohexane 0.4–4 1.2–15

Note: see table notes on the following page
Health Hazard Evaluation Report 2017-0006-3319 Page 21

Table A3 (continued). Table of target analytes for VOCs in air samples during tattoo removal from 

pig skin (in ppb)

Analyte Minimum detectable 

concentration*

Minimum quantifiable 

concentration*

Dibromochloromethane 0.08–4 1.2–15

Dichlorodifluoromethane 0.2–4 1.2–15

Dichlorotetrafluoroethane 0.9–4 1.2–15

Ethyl acetate 0.1–4 1.2–15

Ethylbenzene 0.2–4 1.2–15

Heptane 0.1–4 1.2–15

Hexachlorobutadiene 0.3–4 1.2–15

Hexane 0.1–4 1.2–15

Isopropyl alcohol 500–900 1,400–1,700

m & p-Xylene 0.3–4 1.2–15

Methyl tert-butyl ether 0.1–4 1.2–15

Methylene chloride 0.09–4 1.2–15

Naphthalene 0.6–9 2.4–29

o-Xylene 0.2–4 1.2–15

Propene 0.3–4 1.2–15

Styrene 0.2–4 1.2–15

Tetrachloroethene 0.2–4 1.2–15

Tetrahydrofuran 0.3–4 1.2–15

Toluene 0.1–4 1.2–15

trans-1,2-dichloroethene 0.08–4 1.2–15

trans-1,3-dichloropropene 0.1–4 1.2–15

Trichloroethene 0.1–4 1.2–15

Trichlorofluoromethane 0.3–4 1.2–15

Trichlorotrifluoroethane 0.08–4 1.2–15

Vinyl acetate 0.08–4 1.2–15

Vinyl chloride 0.7–4 1.2–15

*These values varied slightly from sample to sample. The most conservative numbers are 

listed here.
Page 22 Health Hazard Evaluation Report 2017-0006-3319

Appendix B: Bacterial 16S rDNA Amplification, 

Cloning, and Sanger Sequencing 

We amplified bacterial 16S ribosomal DNA (rDNA) sequences using the highly 

conserved primer pair p8FPL (AGTTTGATCCTGGCTCAG) and p806R 

(GGACTACCAGGGTATCTAAT) as previously described [Broadwater et al. 2016; 

McCabe et al. 1999]. We amplified the bacterial 16S rRNA genes with Invitrogen Platinum 

Taq DNA polymerase by a modified method of [McCabe et al. 1999]. The polymerase chain 

reaction (PCR) conditions included initial denaturation at 95°C for 4 minutes, followed by 

33 cycles of denaturation at 94°C for 1 minute, annealing at 55°C for 1 minute, extension at 

72°C for 2 minutes, and completion with a final extension at 72°C for 10 minutes. We ran 

three 50 microliters replicate PCR reactions for each sample with the use of 5 microliters of 

DNA template. We combined the replicates, and the rDNA amplicons were purified with a 

Qiagen PCR purification kit according to the manufacturer’s instructions. We ran the purified 

product (8 microliters) on a 1% agarose gel containing 1 microgram per milliliter ethidium 

bromide and examined for amplicons with ultraviolet light.

We cloned bacterial amplicons into the pDRIVE vector using a Qiagen PCR cloning kit. We 

generated clone libraries by transforming cloned plasmids into chemically competent 

Escherichia coli cells as previously described [Broadwater et al. 2016]. We selected positive 

colonies (as determined colorimetrically by the inactivation of the lacZ gene) and cultured 

for 16 hours at 37°C in liquid Luria-Bertani media containing 100 micrograms per milliliter 

of ampicillin. Resultant cells were centrifuged at 1800 × g (relative centrifugal force) and the 

pellet resuspended in 200 microliters of 15% glycerol, and sent for Sanger sequencing of the 

bacterial 16S insert from Genewiz, Inc. Inserts were sequenced in both directions, allowing 

for sequence analysis of the 16S region. 

Sequencing results were downloaded as “.ab1” chromatogram files from Genewiz Inc. Vector 

sequence data were trimmed and forward and reverse sequences were assembled using 

Biomatters Geneious R7 Software. Then we sequenced the DNA to identify which varieties 

of bacteria were present in the air. Sequence data were then clustered into operational 

taxonomic units with MOTHUR software version 1.32.1 using a 97% similarity cutoff as 

described in previous publications [Broadwater et al. 2016; Schloss et al. 2009]. Sequences 

representative of each taxonomic unit were then used in a Basic Local Alignment Search Tool 

search against the National Center for Biotechnology Information database to identify the 

bacterial species present.
Health Hazard Evaluation Report 2017-0006-3319 Page 23

Appendix C: Tattoo Removal Information

Table C1. Information about tattoo removals from pig skin

Number in 

Figure 1

Tattoo color Laser wavelength 

(nm)

Laser pulse rate Tattoo removal 

duration (minutes)

1 Black 1,064 750 picoseconds 6

2 Black 1,064 2 nanoseconds 7

3 Yellow 532 750 picoseconds 5

4 Yellow 532 2 nanoseconds 8

5 Red 532 750 picoseconds 7

6 Red 532 2 nanoseconds 6

7 Green 755 4 nanoseconds 6

8 Green 1,064 750 picoseconds 1

9 Green 532 2 nanoseconds 1

10 Green 532 750 picoseconds 4

11 Blue 755 4 nanoseconds 5

12 Blue 1,064 750 picoseconds 4

Table C2. Information about tattoo removals from patients

Tattoo 

number

Tattoo color Laser wavelength 

(nm)

Laser pulse rate Tattoo removal 

duration (minutes)

1 Black 1,064 750 picoseconds 8

2 Black 1,064 750 picoseconds 3

3 Black 1,064 750 picoseconds 3

4 Black 1,064 750 picoseconds 19

4 Red 532 Q-switch 6

4 Yellow 532 Q-switch 5

4 Blue 694 Q-switch 8

4 Blue 694 Q-switch 3

5 Blue/Green 694 Q-switch 13

6 Black 1,064 750 picoseconds 3
Page 24 Health Hazard Evaluation Report 2017-0006-3319

Appendix D: Supplementary Table for Bulk Tattoo 

Ink Analysis

Table D1. Bulk results for elements in various colors of ink (milligrams per kilogram of ink)*

Analyte Blue ink Red ink Black ink Yellow ink Light green ink Light blue ink

Aluminum ND 50 ND 360 1,300 7,600

Barium ND [6.5] ND [5.3] [5.0] ND

Cadmium ND [0.46] [0.24] ND ND ND

Calcium 130 190 ND [50] 97 [68]

Chromium 2.1 3.9 1.4 ND 2.2 [0.75]

Cobalt ND ND ND [1.0] [1.2] 4.2

Copper 22,000 3.0 0.97 [0.43] 5,500 4,900

Iron [14] 41 [9.7] ND [32] ND

Lead [17] ND ND ND ND ND

Lithium [0.33] ND ND ND ND [13]

Magnesium 9.6 21 4.6 32 38 ND

Manganese 3.7 ND ND ND ND 14

Molybdenum 56 ND ND ND ND 13

Nickel [0.82] ND ND ND [0.75] [1.3]

Phosphorus 1,600 [95] ND [100] 630 460

Potassium ND 7.2 130 7.8 24 5.3

Silver [1.8] ND ND ND [1.5] [9.2]

Strontium [0.26] 1.9 [0.15] 0.56 2.8 [0.29]

Tellurium ND ND ND ND ND [3.9]

Thallium 12 [2.6] [2.0] [3.1] [2.9] ND

Titanium [1.2] 130 ND 620 650 2,600

Vanadium ND ND ND ND ND 2.2

Yttrium [0.077] [0.052] ND ND [0.052] ND

Zinc [25] ND ND ND ND ND

Zirconium 7.6 7.1 6.2 63 150 1,400

[ ] = Estimated concentration; this concentration was between the minimum detectable 

concentration and the minimum quantifiable concentration.

*The minimum quantifiable concentrations are listed in Appendix A, Table A1.
Health Hazard Evaluation Report 2017-0006-3319 Page 25

Appendix E: Occupational Exposure Limits and 

Health Effects

NIOSH investigators refer to mandatory (legally enforceable) and recommended OELs for 

chemical, physical, and biological agents when evaluating workplace hazards. OELs have 

been developed by federal agencies and safety and health organizations to prevent adverse 

health effects from workplace exposures. Generally, OELs suggest levels of exposure that 

most employees may be exposed to for up to 10 hours per day, 40 hours per week, for a 

working lifetime, without experiencing adverse health effects. However, not all employees 

will be protected if their exposures are maintained below these levels. Some may have 

adverse health effects because of individual susceptibility, a pre-existing medical condition, 

or a hypersensitivity (allergy). In addition, some hazardous substances act in combination 

with other exposures, with the general environment, or with medications or personal habits of 

the employee to produce adverse health effects. Most OELs address airborne exposures, but 

some substances can be absorbed directly through the skin and mucous membranes.

Most OELs are expressed as a time weighted average exposure. A time weighted average 

refers to the average exposure during a normal 8- to 10-hour workday. Some chemical 

substances and physical agents have recommended short-term exposure limit or ceiling 

values. Unless otherwise noted, the short term exposure limit is a 15-minute time weighted 

average exposure. It should not be exceeded at any time during a workday. The ceiling limit 

should not be exceeded at any time.

In the United States, OELs have been established by federal agencies, professional 

organizations, state and local governments, and other entities. Some OELs are legally 

enforceable limits; others are recommendations. 

● The U.S. Department of Labor OSHA Permissible Exposure Limits (29 CFR 1910 

[general industry]; 29 CFR 1926 [construction industry]; and 29 CFR 1917 [maritime 

industry]) are legal limits. These limits are enforceable in workplaces covered under the 

Occupational Safety and Health Act of 1970. 

● NIOSH Recommended Exposure Limits are recommendations based on a critical 

review of the scientific and technical information and the adequacy of methods 

to identify and control the hazard. NIOSH Recommended Exposure Limits are 

published in the NIOSH Pocket Guide to Chemical Hazards [NIOSH 2010]. NIOSH 

also recommends risk management practices (e.g., engineering controls, safe work 

practices, employee education/training, PPE, and exposure and medical monitoring) to 

minimize the risk of exposure and adverse health effects.

● Another set of OELs commonly used and cited in the United States is the ACGIH 

Threshold Limit Values (TLVs). The TLVs are developed by committee members of 

this professional organization from a review of the published, peer-reviewed literature. 

TLVs are not consensus standards. They are considered voluntary exposure guidelines 

for use by industrial hygienists and others trained in this discipline “to assist in the 

control of health hazards” [ACGIH 2018].
Page 26 Health Hazard Evaluation Report 2017-0006-3319

Outside the United States, OELs have been established by various agencies and organizations 

and include legal and recommended limits. The Institut für Arbeitsschutz der Deutschen 

Gesetzlichen Unfallversicherung (Institute for Occupational Safety and Health of the German 

Social Accident Insurance) maintains a database of international OELs from European Union 

member states, Canada (Québec), Japan, Switzerland, and the United States. The database, 

available at http://www.dguv.de/ifa/GESTIS/GESTIS-Internationale-Grenzwerte-fürchemische-Substanzen-limit-values-for-chemical-agents/index-2.jsp, contains international 

limits for more than 2,000 hazardous substances and is updated periodically. 

OSHA requires an employer to furnish employees a place of employment free from 

recognized hazards that cause or are likely to cause death or serious physical harm 

[Occupational Safety and Health Act of 1970 (Public Law 91–596, sec. 5(a)(1))]. This is 

true in the absence of a specific OEL. It also is important to keep in mind that OELs may not 

reflect current health-based information.

When multiple OELs exist for a substance or agent, NIOSH investigators generally 

encourage employers to use the lowest OEL when making risk assessment and risk 

management decisions. NIOSH investigators also encourage use of the hierarchy of controls 

approach to eliminate or minimize workplace hazards. This includes, in order of preference, 

the use of (1) substitution or elimination of the hazardous agent, (2) engineering controls 

(e.g., local exhaust ventilation, process enclosure, dilution ventilation), (3) administrative 

controls (e.g., limiting time of exposure, employee training, work practice changes, medical 

surveillance), and (4) PPE (e.g., respiratory protection, gloves, eye protection, hearing 

protection). Control banding, a qualitative risk assessment and risk management tool, is a 

complementary approach to protecting employee health. Control banding focuses on how 

broad categories of risk should be managed. Information on control banding is available at 

http://www.cdc.gov/niosh/topics/ctrlbanding/. This approach can be applied in situations 

where OELs have not been established or can be used to supplement existing OELs.
Health Hazard Evaluation Report 2017-0006-3319 Page 27

Appendix F: Supplementary Tables for Volatile 

Organic Compound Results

Table F1. Instantaneous air sample for VOCs near the 

pig skin with black tattoo ink (in ppb)*†

Analyte Picosecond 

laser

Nanosecond 

laser

1,2,4-Trimethylbenzene [0.14] [0.14]

1,3-Butadiene ND 1.6

2-Butanone 1.0 [0.72]

Acetone 27 56

Benzene [0.58] 1.5

Carbon disulfide ND [0.24]

Chloroform [0.12] ND

Chloromethane [0.78] [0.70]

Dichlorodifluoromethane [0.50] [0.52]

Ethyl acetate [0.23] [0.16]

Ethylbenzene [0.29] [0.30]

Heptane [0.12] [0.12]

Hexane [0.25] [0.24]

Isopropyl alcohol 15,000 26,000

m & p-Xylene [0.91] [0.66]

Methylene chloride [0.27] [0.24]

o-Xylene [0.29] [0.24]

Propene 2.0 6.4

Styrene ND 1.1

Toluene [0.89] 1.2

Trichlorofluoromethane [0.41] [0.62]

[ ] = Estimated concentration; this concentration was between 

the minimum detectable concentration and the minimum 

quantifiable concentration.

*The minimum quantifiable concentrations are listed in 

Appendix A, Table A3.

†The duration of this sample was approximately 30 seconds.
Page 28 Health Hazard Evaluation Report 2017-0006-3319

Table F2. Instantaneous air sample for VOCs near the pig 

skin with yellow tattoo ink (in ppb)*†

Analyte Picosecond 

laser

Nanosecond 

laser

1,2,4-Trimethylbenzene [0.14] [0.13]

1,3-Butadiene 1.8 4.6

2-Butanone [0.70] [0.79]

Acetone 77 30

Benzene 1.1 1.8

Carbon disulfide ND [0.19]

Chlorobenzene ND [0.13]

Chloromethane [0.98] 1.1

Dichlorodifluoromethane 1.2 [0.49]

Ethyl acetate [0.16] [0.13]

Ethylbenzene [0.22] [0.28]

Heptane [0.14] [0.15]

Hexane [0.24] [0.25]

Isopropyl alcohol 45,000 59,000

m & p-Xylene [0.62] [0.62]

Methylene chloride [0.60] [0.25]

Naphthalene 12 ND

o-Xylene [0.26] [0.32]

Propene 4.5 9.0

Styrene [0.32] [0.55]

Toluene 1.2 1.6

Trichlorofluoromethane [0.80] [0.83]

[ ] = Estimated concentration; this concentration was 

between the minimum detectable concentration and the 

minimum quantifiable concentration.

*The minimum quantifiable concentrations are listed in 

Appendix A, Table A3.

†The duration of this sample was approximately 30 seconds.
Health Hazard Evaluation Report 2017-0006-3319 Page 29

Table F3. Instantaneous air sample for VOCs near the pig 

skin with red tattoo ink (in ppb)*†

Analyte Picosecond 

laser

Nanosecond 

laser

1,2,4-Trimethylbenzene [0.27] [0.12]

1,3-Butadiene 14 3.2

1,4-Dichlorobenzene [0.55] ND

2,2,4-Trimethylpentane ND [0.18]

2-Butanone ND [0.55]

4-Methyl-2-pentanone [0.14] ND

Acetone 49 31

Benzene 24 2.7

Carbon disulfide [0.25] [0.12]

Chlorobenzene [0.69] ND

Chloromethane 2.2 [0.81]

Dichlorodifluoromethane [0.51] [0.53]

Ethyl acetate [0.35] [0.20]

Ethylbenzene 1.2 [0.32]

Heptane [0.18] [0.14]

Hexane [0.27] [0.22]

Isopropyl alcohol 10,000 9,800

m & p-Xylene 1.2 [0.55]

Methylene chloride [0.31] [0.32]

Naphthalene [0.59] ND

o-Xylene [0.55] [0.22]

Propene 34 6.7

Styrene 29 4.0

Tetrahydrofuran [0.45] ND

Toluene 6.3 1.3

Trichlorofluoromethane [0.78] [0.81]

Vinyl chloride [0.59] ND

[ ] = Estimated concentration; this concentration was 

between the minimum detectable concentration and the 

minimum quantifiable concentration.

*The minimum quantifiable concentrations are listed in 

Appendix A, Table A3.

†The duration of this sample was approximately 30 seconds.
Page 30 Health Hazard Evaluation Report 2017-0006-3319

Table F4. Instantaneous air sample for VOCs near the pig 

skin with green tattoo ink (in ppb)*†

Analyte 755 nm 

wavelength

532 nm 

wavelength

1,2,4-Trichlorobenzene [0.54] ND

1,2,4-Trimethylbenzene [0.18] ND

1,2-Dichlorobenzene [0.36] ND

1,3-Butadiene 42 ND

1,3-Dichlorobenzene [0.26] ND

1,4-Dichlorobenzene [0.16] ND

2,2,4-Trimethylpentane [0.26] ND

2-Butanone [0.84] ND

Acetone 36 ND

Benzene 37 ND

Benzyl chloride [0.78] ND

Carbon disulfide 2.2 ND

Chlorobenzene 11 ND

Chloroethane [0.70] ND

Chloromethane 13 ND

Dichlorodifluoromethane [0.52] ND

Ethyl acetate [0.40] ND

Ethylbenzene 3.6 ND

Hexane [0.38] ND

Isopropyl alcohol 13,000 13,000

m & p-Xylene [0.80] ND

Methylene chloride [0.54] ND

Naphthalene 3.7 ND

o-Xylene [0.68] ND

Propene 110 ND

Styrene 69 ND

Toluene 14 ND

Trichlorofluoromethane [0.72] ND

Vinyl chloride 2.9 ND

[ ] = Estimated concentration; this concentration was 

between the minimum detectable concentration and the 

minimum quantifiable concentrations.

*The minimum quantifiable concentrations are listed in 

Appendix A, Table A3.

†The duration of this sample was approximately 30 seconds.
Health Hazard Evaluation Report 2017-0006-3319 Page 31

Table F5. Instantaneous air sample for VOCs near the 

pig skin with dark blue tattoo ink and a wavelength of 

755 nm (in ppb)*†

Analyte Result

1,2,4-Trimethylbenzene [0.14]

1,3-Butadiene 11

2,2,4-Trimethylpentane [0.18]

2-Butanone [0.86]

Acetone 63

Benzene 26

Carbon disulfide [0.22]

Chloromethane 1.0

Dichlorodifluoromethane [0.50]

Ethyl acetate [0.26]

Ethylbenzene 1.5

Heptane [0.16]

Hexane [0.26]

Isopropyl alcohol 14,000

m & p-Xylene [0.68]

Methylene chloride [0.32]

Naphthalene [1.7]

o-Xylene [0.40]

Propene 35

Styrene 54

Toluene 6.5

Trichlorofluoromethane [0.60]

[ ] = Estimated concentration; this concentration was 

between the minimum detectable concentration and the 

minimum quantifiable concentration.

*The minimum quantifiable concentrations are listed in 

Appendix A, Table A3.

†The duration of this sample was approximately 30 seconds.
Page 32 Health Hazard Evaluation Report 2017-0006-3319

Table F6. Instantaneous air sample for VOCs during removal of black tattoos using a 

wavelength of 1,064 nm (in ppb)*†

Analyte Tattoo 1 Tattoo 2 Tattoo 3 Tattoo 4 Tattoo 5

Acetone 28 29 29 28 [1.1]

Ethyl acetate [2.2] [2.1] [1.8] [1.6] 54

Ethylbenzene 7.3 6.7 5.9 5.3 [1.6]

Isopropyl alcohol 3,600 4,400 4,100 4,300 7.0

m & p-Xylene 20 19 17 15 4,400

o-Xylene 4.4 4.0 [3.6] [3.2] 21

[ ] = Estimated concentration; this concentration was between the minimum detectable 

concentration and the minimum quantifiable concentration.

*The minimum quantifiable concentrations are listed in Appendix A, Table A3.

†The duration of this sample was approximately 30 seconds.

Table F7. Instantaneous air sample for VOCs during removal 

of a red tattoo using a wavelength of 532 nm (in ppb)*†

Analyte Result

Acetone [230]

Ethyl acetate [1.3]

Ethylbenzene 4.1

Isopropyl alcohol 6,200

m & p-Xylene 12

o-Xylene [2.5]

[ ] = Estimated concentration; this concentration was 

between the minimum detectable concentration and the 

minimum quantifiable concentration.

*The minimum quantifiable concentrations are listed in 

Appendix A, Table A3.

†The duration of this sample was approximately 30 seconds.
Health Hazard Evaluation Report 2017-0006-3319 Page 33

Table F8. Instantaneous air sample for VOCs during 

removal of a yellow tattoo using a wavelength of 

532 nm (in ppb)*†

Analyte Result

Acetone 46

Ethyl acetate [1.2]

Ethylbenzene 3.9

Isopropyl alcohol 7,100

m & p-Xylene 11

o-Xylene [2.4]

Propene [1.9]

[ ] = Estimated concentration; this concentration was 

between the minimum detectable concentration and the 

minimum quantifiable concentration.

*The minimum quantifiable concentrations are listed in 

Appendix A, Table A3.

†The duration of this sample was approximately 30 seconds.

Table F9. Instantaneous air sample for VOCs during removal 

of blue/green tattoos using a wavelength of 694 nm (in ppb)*†

Analyte Tattoo 1 Tattoo 2

Acetone 38 35

Ethyl acetate [1.6] [2.0]

Ethylbenzene 4.8 9.0

Isopropyl alcohol 7,600 3,200

m & p-Xylene 14 27

o-Xylene [3.0] 6.1

Propene [1.8] ND

Toluene ND [1.7]

[ ] = Estimated concentration; this concentration was 

between the minimum detectable and minimum 

quantifiable concentration.

*The minimum quantifiable concentrations are listed in 

Appendix A, Table A3.

†The duration of this sample was approximately 30 seconds.
Page 34 Health Hazard Evaluation Report 2017-0006-3319

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Keywords: North American Industry Classification System (NAICS) 621111 (Offices of 

Physicians [except Mental Health Specialists]), Massachusetts, Laser, Tattoo Removal, 

Dermatology, Metals, Particles, Bacteria, Fungi, Volatile Organic Compounds
Health Hazard Evaluation Report 2017-0006-3319 Page 37

The Health Hazard Evaluation Program investigates possible health hazards in the workplace 

under the authority of the Occupational Safety and Health Act of 1970 (29 U.S.C. § 669(a)

(6)). The Health Hazard Evaluation Program also provides, upon request, technical assistance 

to federal, state, and local agencies to investigate occupational health hazards and to prevent 

occupational disease or injury. Regulations guiding the Program can be found in Title 42, Code 

of Federal Regulations, Part 85; Requests for Health Hazard Evaluations (42 CFR Part 85).

Disclaimer

The recommendations in this report are made on the basis of the findings at the workplace 

evaluated and may not be applicable to other workplaces.

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Acknowledgments

Analytical Support: Maxxam Analytics

Desktop Publisher: Shawna Watts 

Editor: Ellen Galloway 

Logistics: Donnie Booher, Kevin Moore

Availability of Report

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local health department and the Occupational Safety and Health Administration Regional Office 

have also received a copy. This report is not copyrighted and may be freely reproduced. 

Recommended citation for this report:

NIOSH [2018]. Characterizing exposures during laser tattoo removal in a hospital 

dermatology center. By Grant MP, Glassford E, Green B, Lemons A. Cincinnati, OH: U.S. 

Department of Health and Human Services, Centers for Disease Control and Prevention, 

National Institute for Occupational Safety and Health, Health Hazard Evaluation Report 

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