Evaluation of Exposures and 

Health Concerns in a Dental 

Clinic

HHE Report No. 2019-0134-3375

November 2020
Authors: Brie H. Blackley, MS, PhD

Ethan D. Fechter-Leggett, DVM, MPVM

Alyson R. Fortner, MPH, PhD

Analytical Support: Ryan LeBouf and Dru Burns

Desktop Publisher: Barbara Elbon

Industrial Hygiene Field Assistance: Randy Boylstein and Michael Beaty

Data Support: Nicole Edwards and Brian Tift

Keywords: North American Industry Classification System (NAICS) 621210 (Healthcare and Social 

Assistance), New Jersey, Dental Clinics, Exposure Assessment, Mercury, Volatile Organic 

Compounds, Respirable Dust

Disclaimer

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).

Availability of Report

Copies of this report have been sent to the employer and employees at the dental clinic. The state 

and 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

NIOSH [2020]. Evaluation of exposures and health concerns in a dental clinic. By Blackley BH, 

Fechter-Leggett ED, Fortner AR. Morgantown, WV: 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 2019-0134-3375, 

https://www.cdc.gov/niosh/hhe/reports/pdfs/2019-0134-3375.pdf.
Table of Contents

Main Report

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

Our Approach ...................................................................................................................................................1

Our Key Findings..............................................................................................................................................2

Our Recommendations....................................................................................................................................5

Supporting Technical Information

Section A Workplace Information.............................................................................................................A-1

Employee Information ..........................................................................Error! Bookmark not defined.

Process Description .................................................................................................................................A-1

Section B Methods and Results.................................................................................................................. B-1

Section C Tables........................................................................................................................................... C-1

Section D Occupational Exposure Limits................................................................................................D-1

Section E References................................................................................................................................... E-3
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1

Introduction

Request

We received a management request for a health hazard evaluation at a dental clinic. The request stated 

concerns about possible exposure to mercury vapors from amalgam, a metal alloy used for dental 

fillings.

Workplace

The dental clinic provides dental care services to patients. Services include general dentistry, family 

dentistry, cosmetic dentistry, restorative dentistry, full-mouth reconstruction, and oral surgery services. 

At the time of our survey, the clinic employed 17 staff, including three dentists, dental hygienists, dental 

assistants, administrative staff, and a business administrator.

To learn more about the workplace, go to Section A in the Supporting Technical Information

Our Approach

In June 2019, we conducted a site visit to assess possible exposures during routine dental care, assess

the ventilation systems in use, and informally interview clinic staff. During our survey in June 2019, we

• Collected full-shift time-weighted average (TWA) samples on dental clinic employees while they 

performed their regular job duties and analyzed for elemental mercury content.

• Collected full-shift TWA area samples in multiple locations in the dental clinic and analyzed for 

respirable dust, respirable silica, respirable metals, and volatile organic compound (VOC)

concentrations.

o Full-shift TWA areas samples for VOCs were collected with two different samplers, 

placed side-by-side.

• Collected instantaneous task-based and area air samples for VOCs during various tasks and 

procedures.

• Assessed the heating, ventilation, and air-conditioning (HVAC) systems in use.

• Informally interviewed clinic staff to learn about any health concerns potentially related to 

exposures at work.

To learn more about our methods, go to Section B in the Supporting Technical Information
2

Our Key Findings

All personal air samples for elemental mercury were below the NIOSH

recommended exposure limit (REL) of 50 micrograms per cubic meter of air 

(μg/m3)

• Full-shift, TWA air samples for elemental mercury ranged from less than 0.1 to 0.5 μg/m3.

All area air samples for respirable dust, respirable silica, and respirable metals were 

low

• Because area air samples are not personal air samples collected directly on an employee, the 

NIOSH RELs are not directly applicable to the results for exposure monitoring purposes. 

However, area air samples can highlight areas with higher exposure risk, and the RELs can be 

used as points of reference.

• All samples for respirable dust were below the limit of detection with the exception of one air 

sample collected in Exam Room 5, which measured 17.6 μg/m3 of respirable dust. 

o This sample was well below the Occupational Safety and Health Administration (OSHA)

permissible exposure limit of 5,000 μg/m3 (5 milligrams per cubic meter of air [mg/m3]) 

and the American Conference of Governmental Industrial Hygienists (ACGIH®)

threshold limit value (TLV®) of 3,000 μg/m3 (3 mg/m3) for respirable dust.

• All samples for respirable crystalline silica (cristobalite, tridymite, and quartz) were below their 

respective limits of detection.

• All samples analyzed for respirable metals were below their respective NIOSH RELs.

• Manganese (4.4 μg/m3) had the highest measurement of any metal analyzed. This air sample was 

collected in Exam Room 6 and was far below the NIOSH REL for manganese of 1,000 μg/m3 

(1 mg/m3).

Some VOCs were higher in some locations or during specific tasks or procedures

All air samples for full-shift area air measurements of VOCs were relatively low with the exception of 

measurements for ethanol, isopropyl alcohol, and acetone. Possible sources of these VOCs included

cleaning agents, primer materials, and bonding agents. Ethanol and isopropyl alcohol are chemicals 

commonly used for cleaning and disinfection procedures. Acetone is a solvent used in some dental 

restorative primer materials. Ethanol and acetone are sometimes used with dental bonding agents as 

well. The NIOSH RELs for ethanol, isopropyl alcohol, and acetone are 1,000 ppm (1,000,000 ppb), 400 

ppm (400,000 ppb), and 250 ppm (250,000 ppb), respectively. Because area air samples are not personal 

air samples collected directly on an employee, the NIOSH RELs are not directly applicable to the 

results for exposure monitoring purposes. However, area air samples can highlight areas with higher 

exposure risk, and the occupational exposure limits (OELs) can be used as points of reference.

o Full-shift TWA results for ethanol
3

 Full-shift TWA results from canister samples from all areas sampled measured 

2116.9 parts per billion (ppb) ethanol to measurements above the calibration 

maximum used by the laboratory performing sample analyses. Samples with 

measurements above the calibration maximum were not quantifiable and were 

not reported by the laboratory analyzing the samples.

 All full-shift TWA thermal desorption tubes had measurements for ethanol above 

the calibration maximum used by the laboratory analyzing the samples. The 

calibration maximum for the thermal desorption tubes used to collect VOCs was 

139 nanogram (ng) ethanol. This maximum equates to approximately 8.19 parts 

per million (ppm) ethanol. 

o Full-shift TWA results for isopropyl alcohol

 All full-shift TWA results from canister samples and thermal desorption tubes 

had measurements for isopropyl alcohol above the calibration maximum. The 

calibration maximum for the thermal desorption tubes used to collect VOCs was 

165 ng isopropyl alcohol. This maximum equates to approximately 7.46 ppm 

isopropyl alcohol. The calibration maximum for samples evacuated canisters was 

approximately 48.5 ppb for isopropyl alcohol.

o Full-shift TWA results for acetone

 Full-shift TWA measurements from thermal desorption tubes ranged from 101.1 

ppb to 743.0 ppb acetone. All full-shift canister samples had measurements of 

acetone above the calibration maximum. The calibration maximum for 

measurements collected using evacuated canisters was approximately 48.5 ppb for 

acetone. The calibration maximum for the thermal desorption tubes used to 

collect VOCs was 160 ng acetone. This maximum equates to approximately 7.48 

ppm acetone.

o Full-shift TWA results for other notable VOCs

 Full-shift TWA measurements from canister samples measured methyl 

methacrylate at levels ranging from 9.3 ppb to 63.8 ppb and styrene at levels 

ranging from less than 2.1 ppb to 46.3 ppb. As a point of reference, the NIOSH 

REL is 100 ppm (100,000 ppb) for methyl methacrylate and 50 ppm (50,000 ppb) 

styrene. We note that because area air samples are not personal air samples 

collected directly on an employee, the NIOSH RELs are not directly applicable to 

the results for exposure monitoring purposes. However, area air samples can 

highlight areas with higher exposure risk, and the OELs can be used as points of 

reference.

• The highest instantaneous measurements collected using evacuated canisters during a task were 

measurements of ethanol and isopropyl alcohol. Ethanol and isopropyl alcohol measurements 

collected in the breathing zone of an employee while using the sandblaster in the laboratory

were above the calibration maximum. The calibration maximum for instantaneous 
4

measurements collected using evacuated canisters was approximately 53.1 ppb for ethanol and 

48.5 ppb for isopropyl alcohol.

o The highest instantaneous measurements collected near sources were also measurements 

of ethanol and isopropyl alcohol. Instantaneous air samples were collected in Exam 

Room 2 while an employee placed amalgam into a patient’s mouth or removed amalgam 

from a patient’s mouth. Some ethanol and isopropyl alcohol measurements were above 

the laboratory’s calibration maximum.

o The second highest instantaneous measurements collected near sources were 

measurements of acetone collected in Exam Room 2 while an employee placed amalgam 

into a patient’s mouth or removed amalgam from a patient’s mouth. Acetone 

measurements ranged from 156.5 ppb to 193.8 ppb.

o The highest instantaneous measurements collected in general areas were also 

measurements of ethanol and isopropyl alcohol. Instantaneous air samples were collected 

in the (1) center of the downstairs laboratory which was no longer in use, (2) center of a

downstairs dentist’s office, and (3) in a downstairs storage closet used to store electrical 

equipment and scrubs. Ethanol and isopropyl alcohol measurements were above the 

calibration maximum used by the laboratory analyzing the samples.

o The second highest instantaneous measurements collected in general areas were 

measurements of methyl methacrylate (125.5 ppb), collected in the center of the 

downstairs laboratory, which was no longer in use, and acetone (180.2 ppb), collected in 

the center of Exam Room 2 at the completion of an amalgam replacement.

The laboratory area was under positive pressure relative to adjacent areas and 

could serve as a source of air contaminants

• Positive pressure in the laboratory area could lead to entrainment of air and contaminants from 

the laboratory area in adjacent areas such as the breakroom.

• Although no air sampling results exceeded any occupational exposure limits, the positive 

pressure differential between the laboratory area and adjacent spaces could cause air and 

contaminants from the laboratory area to migrate into adjacent spaces in the future.

Some employees reported eye and nose symptoms that were better when away 

from work.

• Of the 15 clinic staff that were informally interviewed, seven employees reported eye symptoms. 

One of the seven employees who reported eye symptoms indicated that their symptoms 

improved while away from work (n=1/7 or 14.3%)

• Six employees reported nasal symptoms, and two of the six employees indicated that their 

symptoms improved while away from work (n=2/6 or 33.3%). One of the two employees with 

work-related nasal symptoms indicated that acrylics, such as resins used for temporary crowns or 

dentures, seemed to cause or worsen their nasal symptoms.
5

To learn more about our results, go to Section B in the Supporting Technical Information

Our Recommendations

The Occupational Safety and Health Act requires employers to provide a safe workplace.

Benefits of Improving Workplace Health and Safety:

 Improved worker health and well-being  Improved image and reputation 

 Better workplace morale  Better products, processes, and services

 Better employee recruiting and retention  Could increase overall cost savings

The recommendations below are based on the findings of our evaluation. For each recommendation, 

we list a series of actions you can take to address the issue at your workplace. The actions at the 

beginning of each list are preferable to the ones listed later. The list order is based on a well-accepted 

approach called the “hierarchy of controls.” The hierarchy of controls 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 personal protective equipment might be needed. Read more about the hierarchy of 

controls here: https://www.cdc.gov/niosh/topics/hierarchy/

We encourage the company to use a health and safety committee to discuss our 

recommendations and develop an action plan. Both employee representatives and 

management representatives should be included on the committee. Helpful guidance can be 

found in “Recommended Practices for Safety and Health Programs”: 

https://www.osha.gov/shpguidelines/index.html

Recommendation 1: Reduce risk of entrainment of air from the laboratory into 

adjacent spaces

Why? The relationship between supply air and exhaust air flow rates can be used to help maintain 

appropriate pressure relationships. If more air is supplied than exhausted, the space will generally be 

under positive pressure, which allows contaminants to migrate from the space to adjacent areas. 

Conversely, exhausting more air than is supplied, maintains the space under negative pressure which 

helps contain the contaminants in the area where they are generated. The laboratory space under 

positive pressure relative to adjacent spaces can serve as a source of contaminants that are spread 

beyond the laboratory. Although all air measurements collected for particulates and vapors were 

relatively low, there is a potential for future exposures or contaminants generated in the laboratory 

area to be entrained into adjacent spaces.
6

How? At your workplace, we recommend these specific actions:

Ensure the laboratory area is maintained under negative pressure relative 

to adjacent areas.

• Consult with a ventilation engineer to increase the air flow of the return air to the 

laboratory space and to ensure the laboratory is maintained under negative pressure 

relative to adjacent spaces.

• Although there are no specific ASHRAE guidelines for dental clinics, 

ANSI/ASHRAE/ASHE Standard 170-2017, Ventilation of Health Care Facilities, has 

design parameters for healthcare facilities. ASHRAE recommends laboratory work areas 

be kept under negative pressure relative to adjacent spaces.

Recommendation 2: Encourage employees to minimize walking through the 

laboratory area while grinding or sandblasting tasks are being performed 

Particulates generated during abrasive tasks in the laboratory area appeared to be efficiently captured 

by the enclosed abrasive blaster (Micro Cab). However, there can be times when controls designed to 

capture particulates can fail or not operate optimally, and particulates could be released into the air in 

the laboratory space. Minimizing foot traffic through the laboratory area during these tasks would 

minimize risks of possible exposure should the enclosed sandblaster fail to perform optimally. 

Recommendation 3: Make N95 filtering-face piece respirators available for 

voluntary use and train employees on proper use of respiratory protection

Why? We observed employees using surgical masks and triple layer molded face masks. Surgical 

masks are not respirators and do not protect the wearer from inhaling small particulates. Additionally, 

they are not designed to eliminate air leakage around the edges. The triple layer molded face masks 

are designed to absorb liquids, moisture, and microorganisms but do not provide protection against 

particulates. Both types of masks are designed for potential exposures to blood and body fluids but

do not offer protection against particulate, gas, or vapor exposures in the air. Although all 

measurements for particulates were below established exposure limits, if employees desire to 

voluntarily use respiratory protection that also provide protection against particulates during 

particulate generating procedures (e.g., drilling, grinding, and polishing), they should use N95 

disposable filtering-face piece respirators.

How? At your workplace, we recommend these specific actions:
7

Make N95 disposable filtering-face piece respirators available for 

voluntary use for protection against particulates when performing tasks 

that can generate particulates such as drilling, grinding, or polishing.

• Provide training to these employees on how to wear N95 respirators correctly.

• Inform employees that N95 respirators do not protect against exposures to gases or 

vapors.

• Review and share this respirator training tool available at

http://www.cdc.gov/niosh/docs/2010-133/pdfs/2010-133.pdf.

N95 respirators should be available in various sizes, and each potential N95 user should receive a copy 

of Appendix D of the OSHA Respiratory Protection Standard 

(http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=standards&p_id=9784). 

Information about Appendix D and voluntary use of respirators can be found on the OSHA website at 

https://www.osha.gov/video/respiratory_protection/voluntaryuse_transcript.html.

Recommendation 4: Encourage employees to report any new, persistent, or 

worsening respiratory symptoms, particularly those with a work-related pattern, to 

their healthcare providers and, as instructed by their employer, to a designated 

individual at their workplace

Why? Early recognition of work-related respiratory symptoms can help identify potential 

occupational exposures and risk factors for disease and help prioritize interventions to prevent workrelated lung disease in employees. An individualized management plan (such as assigning an affected 

employee to a different work location, perhaps at home or a remote site) is sometimes required, 

depending upon medical findings and recommendations of the individual’s healthcare provider. 
Supporting Technical Information

Evaluation of Exposures and Health Concerns in a 

Dental Clinic

HHE Report No. 2019-0134-3375

November 2020
A-1

Section A: Workplace Information

Workplace

Request basis: Assessment of exposure to mercury vapors from amalgam, a metal alloy used for dental 

fillings.

Previous issues: None.

Employee Information 

At the time of our survey, the clinic employed 17 staff, including three dentists, dental hygienists, dental 

assistants, administrative staff, and a business administrator.

Process Description

At the time of the survey, the dental clinic provided dental care services to patients including general 

dentistry, family dentistry, cosmetic dentistry, restorative dentistry, full-mouth reconstruction, and oral 

surgery services. The clinic had eight examination rooms, a sterilization area, a laboratory space, a 

consultation office, a break room, administrative areas, a patient waiting area, and a laboratory that was 

no longer in use in the lower level of the building. While the exposure assessment was conducted, 

dental staff performed various procedures to include exams, x-rays, cleanings, fluoride treatments, oral 

cancer screenings, composite procedures, drilling, crown procedures, amalgams, anesthesia, extractions, 

denture impressions, orthodontics, root canals, sealants, and periodontitis treatments.

B-1

Section B: Methods, Results, and Discussion

We focused on these objectives: 

• Assess potential for exposure to mercury among dental personnel in the clinic. 

• Evaluate air concentrations of respirable dust, respirable silica, respirable metals, and volatile 

organic compounds (VOCs) in clinic workspaces.

• Assess general exhaust ventilation in the clinic. 

• Informally interview employees about their work history, personal protective equipment use, 

and any work-related symptoms.

Methods: Observations of Workplace and Personal Protective Equipment (PPE)

We observed the workplace while employees performed their job duties and noted use of PPE.

Results: Observation of Work Practices and PPE

Facility Layout

At the time of our survey, the dental clinic was operating in a two-story building. The basement was 

below-grade and included office space, meeting rooms, and storage areas. The main floor was abovegrade and included eight examination rooms, a sterilization area, laboratory space, consultation office, 

break room, administrative areas, a patient waiting area, and a laboratory that was no longer in use in 

the lower level of the building. The examination rooms were open to a main hallway that connected to 

the laboratory space, sterilization area, consultation office, and administrative area. The administrative 

area was confluent with the patient waiting area. The employee break room was accessible through the 

laboratory space or administrative area.

Personal Protective Equipment

We observed employees using surgical masks, triple layer molded face masks, and gloves. The triple 

layer molded face masks are designed to absorb liquids, moisture, and microorganisms. 

Methods: Exposure Assessment

Dental personnel can be exposed to various agents such as chemicals, dusts, bio-aerosols, and metals as 

part of their normal work duties. During this health hazard evaluation, we focused our exposure 

assessment on mercury, respirable dust, respirable metals, and VOCs.

During June 11–13, 2019, we conducted an exposure assessment survey, which consisted of 

(1) observing employees perform various tasks; 

(2) collecting personal air samples for elemental mercury; and

(3) collecting area air samples for respirable dust, respirable metals, respirable silica, and VOCs.
B-2

We collected full-shift time-weighted average (TWA) personal air samples for elemental mercury on 

each day of our survey. 

• The sampling tube was positioned in the employee’s breathing zone, and the tube was 

connected to a sampling pump pulling air at a flow rate of 100 milliliters per minute (mL/min).

• Samples were collected and analyzed according to NIOSH method 6009 [NIOSH 1994].

We also collected area air samples in 11 locations to include eight examination rooms, the laboratory 

area, equipment sterilization area, and front office area on each day of our survey. Area air samples were 

collected using multiple sampling devices to sample for respirable dust, respirable silica, respirable 

metals, and VOCs. 

• Full-shift TWA area samples for respirable dust and respirable silica were collected using a BGI 

respirable cyclone GK2.69 and analyzed in accordance with NIOSH method 0600 for dust

[NIOSH 1998] and NIOSH method 7500 for crystalline silica [NIOSH 2003a].

• Full-shift TWA area samples for respirable metals were also collected using a BGI respirable 

cyclone GK2.69 and analyzed in accordance with NIOSH method 7303 [NIOSH 2003b]. All 

respirable cyclone GK2.69s were connected to a sampling pump pulling air through the cyclone 

at 4.2 liters per minute. 

• Full-shift TWA area samples for VOCs were collected using thermal desorption (TD) tubes and 

evacuated canisters placed side-by-side in different locations in the clinic. TD tubes were 

connected to a sampling pump pulling air through the TD tube at 25 mL/min and were 

collected in accordance with NIOSH method 2549 [NIOSH 1996]. For full-shift sampling using 

TD tubes, we collected two consecutive 3-hour samples and calculated the TWA concentration 

from the two samples, assuming the total 6-hour monitoring results reflected a full work-shift 

(8-hour) TWA exposure. Full-shift TWA samples collected using the TD tubes were analyzed 

using NIOSH method 2549 modified for quantifying compounds listed in NMAM 3900. 

Method modifications included a longer gas chromatograph column (Rxi-1ms, 60 meters x 0.32 

millimeters x 1.0 micrometers, Restek Corporation, Bellefonte, PA) to increase compound 

separation and calibrating compound response with a gas-phase calibration standard and internal 

standard loaded onto TD tubes. 

• Evacuated canisters were also used to collect instantaneous task-based and source air samples 

for VOCs. The evacuated canister sampling setup consisted of a 450-mL evacuated canister 

equipped with either a restricted flow controller set at a 6-hour sampling duration or an 

instantaneous flow controller designed for a short sampling duration (less than 30 seconds). 

Full-shift TWA and instantaneous samples collected using the evacuated canisters were analyzed 

in accordance with NIOSH method 3900 using a gas chromatograph-mass spectrometer 

equipped with a pre-concentrator [NIOSH 2018].
B-3

Results: Exposure Assessment

Personal air sampling for elemental mercury exposure

A summary of personal air sampling results for elemental mercury can be seen in Table C1. All samples 

were below the NIOSH recommended exposure limit (REL) of 50 micrograms per cubic meter of air

(μg/m3). Concentrations ranged from <0.1 to 0.5 μg/m3.

Area air sampling for respirable dust and respirable silica

A summary of area air sampling results for respirable dust and respirable silica can be seen in Table C2. 

All samples for respirable dust were below the limit of detection with the exception of one sample 

collected in Exam Room 5, which measured 17.6 μg/m3 of respirable dust. Procedures performed in 

Exam Room 5 while the sample was collected included a patient exam, nightguard placement, and 

crown placement. The sample that measured respirable dust in Exam Room 5 was well below the 

OSHA permissible exposure limit (PEL) of 5,000 μg/m3 (5 mg/m3) and the American Conference of 

Governmental Industrial Hygienists (ACGIH®) threshold limit value (TLV®) of 3,000 μg/m3 (3 

microgram (mg)/m3) for respirable dust [ACGIH 2020; NIOSH 2007; OSHA 2020]. All samples for 

respirable crystalline silica (cristobalite, tridymite, and quartz) were below their respective limits of 

detection. We note here and below, that because area air samples are not personal air samples collected 

directly on an employee, the NIOSH RELs are not directly applicable to the results for exposure 

monitoring purposes. However, area air samples can highlight areas with higher exposure risk, and the 

occupational exposure limits (OELs) can be used as points of reference.

Area air sampling for respirable metals

All samples analyzed for respirable metals were below their respective NIOSH RELs. The highest 

measurement of any metal analyzed was for manganese (4.4 μg/m3) collected in Exam Room 6 and was 

far below the NIOSH REL of 1,000 μg/m3 (1 mg/m3) for manganese. Procedures performed in Exam 

Room 6 while this sample was collected included x-rays, patient exam, periodontitis treatment, sealant, 

oral cancer screen, cleaning (including polishing), and fluoride treatment.

Area air sampling for volatile organic compounds

All samples for full-shift area measurements of VOCs were relatively low with the exception of 

measurements for ethanol, isopropyl alcohol, and acetone. Ethanol and isopropyl alcohol are chemicals 

commonly used for cleaning and disinfection procedures. Acetone is a solvent used in some dental 

restorative primer materials. Ethanol and acetone are sometimes used with dental bonding agents as 

well. The NIOSH RELs for ethanol, isopropyl alcohol, and acetone are 1000 ppm (1,000,000 ppb), 400 

ppm (400,000 ppb), and 250 ppm (250,000 ppb), respectively [NIOSH 2007]. We note again here, that 

because area air samples are not personal air samples collected directly on an employee, the NIOSH 

RELs are not directly applicable to the results for exposure monitoring purposes. However, area air 

samples can highlight areas with higher exposure risk, and the OELs can be used as points of reference.

Full-shift TWA results from canister samples from all areas sampled measured anywhere from 2116.9 

parts per billion (ppb) ethanol to measurements above the calibration maximum used by the laboratory 

performing sample analyses. Samples that were above the calibration maximum were diluted and re-run 
B-4

in an attempt to detect quantities below the calibration maximum. The calibration maximum for 

measurements using evacuated canisters was approximately 53.1 ppb for ethanol. The median dilution 

factor for samples initially above the calibration maximum was 59. A dilution factor of 59 equates to a 

theoretical maximum of 3132.9 ppb ethanol (59 x 53.1 ppb = 3132.9 ppb). All full-shift TWA thermal

desorption tubes had measurements for ethanol that were above the calibration maximum. The 

calibration maximum for the thermal desorption tubes used to collect VOCs was 139 ng ethanol. This 

maximum equates to approximately 8.19 ppm ethanol. 

All full-shift TWA results from canister samples and TD tubes had measurements for isopropyl alcohol 

that were above the calibration maximum. The calibration maximum for the thermal desorption tubes 

used to collect VOCs was 165 nanogram (ng) isopropyl alcohol. This maximum equates to 

approximately 7.46 ppm isopropyl alcohol. The calibration maximum for measurements made using 

evacuated canisters was approximately 48.5 ppb for isopropyl alcohol.

Full-shift TWA measurements from TD tubes ranged from 101.1 ppb to 743.0 ppb acetone. All fullshift canister samples had measurements of acetone that were above the calibration maximum. The 

calibration maximum for the TD tubes used to collect VOCs was 160 ng acetone. This maximum 

equates to approximately 7.48 ppm acetone. The calibration maximum for measurements made using 

evacuated canisters was approximately 48.5 ppb for acetone.

Full-shift TWA measurements from canister samples measured methyl methacrylate at levels ranging 

from 9.3 ppb to 63.8 ppb and styrene at levels ranging from < 2.1 ppb to 46.3 ppb. Full-shift TWA 

measurements from TD tubes ranged from 9.8 ppb to 12.8 ppb methyl methacrylate and < 1.9 ppb to 

< 2.0 ppb styrene. As a point of reference, the NIOSH REL is 100 ppm (100,000 ppb) for methyl 

methacrylate and 50 ppm (50,000 ppb) for styrene, [NIOSH 2007]. We note here and below, that 

because area air samples are not personal air samples collected directly on an employee, the NIOSH 

RELs are not directly applicable to the results for exposure monitoring purposes. However, area air 

samples can highlight areas with higher exposure risk, and the OELs can be used as points of reference.

The highest instantaneous measurements collected near the breathing zone of an employee during a 

task were measurements of ethanol and isopropyl alcohol. Ethanol and isopropyl alcohol 

measurements, collected in the breathing zone of an employee while using the sandblaster in the 

laboratory, were above the calibration maximum. We note that the calibration maximum for 

instantaneous measurements using evacuated canisters was approximately 53.1 ppb for ethanol and 48.5 

ppb for isopropyl alcohol. The highest instantaneous measurements near sources were also 

measurements of ethanol and isopropyl alcohol and were collected in Exam Room 2 while an employee 

placed amalgam into a patient’s mouth or removed amalgam from a patient’s mouth. Ethanol and 

isopropyl alcohol measurements, collected near the patient’s mouth while an employee placed amalgam 

into or removed amalgam from a patient’s mouth, were also above the calibration maximum. 
B-5

The second highest instantaneous measurements collected near sources were measurements of acetone 

collected in Exam Room 2 while an employee placed amalgam into a patient’s mouth or removed 

amalgam from a patient’s mouth. Acetone measurements ranged from 156.5 ppb to 193.8 ppb. 

The highest instantaneous measurements collected in general areas were also measurements of ethanol 

and isopropyl alcohol and were collected in (1) the center of the downstairs laboratory, which was no 

longer in use and closed off from other spaces, (2) the center of the downstairs dentist’s office, and (3) a 

downstairs storage closet used to store electrical equipment and scrubs. Ethanol and isopropyl alcohol 

measurements were above the calibration maximum. The second highest instantaneous measurements 

collected in general areas were measurements of methyl methacrylate (125.5 ppb), collected in the center 

of the downstairs lab which was no longer in use, and acetone (180.2 ppb), collected in the center of 

Exam Room 2 at the completion of an amalgam replacement.

Methods: Ventilation

We assessed the ventilation systems in place. We conducted visual and physical assessments of all 

ventilation components at the facility. Physical dimensions of the facility were measured with a Model 

DISTO E7100i laser-tape measure (Leica Geosystems AG, Heerbrugg, Switzerland). Air flow 

measurements of supply vents and exhaust outlets were taken using an Accubalance Plus Model 8373 

Air Capture Hood (TSI Incorporated, Shoreview, MN). 

Results: Ventilation

Ventilation

The examination rooms, consultation office, and laboratory were under positive pressure relative to 

adjacent spaces. 

Methods: Informal Employee Interviews

During June 11–13, 2019, we conducted individual informal interviews with 15 staff to discuss work 

history, personal protective equipment worn, and health concerns. We also discussed tasks performed

and products used. Most interviews lasted approximately five to 10 minutes.

Results: Informal Employee Interviews

Work History

The 15 employees interviewed worked an average of 4.5 days (range: 3.0–5.0 days) and 37.3 hours 

(range: 24.0–42.5 hours) per week. The average total time worked in the dental industry was 15.5 years 

(range: <1–43 years). Among the 15 employees interviewed, 12 (80.0%) reported ever working at 

another dental-related company.

Personal Protective Equipment Worn by Employees

All employees reported wearing scrubs or a white coat while at work. All employees who reported 

working with patients, performing laboratory tasks, or cleaning rooms reported wearing gloves and 

goggles/eye protection while doing these tasks; 14 of 15 (93.3%) employees reported wearing a surgical 
B-6

mask while doing these tasks. One of 15 (6.7%) employees reported wearing an N95 respirator while 

working with patients. However, we observed that the mask used was a triple layer molded face mask,

and this type of face mask does not offer protection against particulate, gas, or vapor exposures in the 

air.

Work-related Health Symptoms

Overall, seven of 15 (46.7%) interviewed employees reported eye symptoms (such as watery or itchy 

eyes), and one of these seven (14.3%) employees reported their eye symptoms improved while away 

from work. No specific products or tasks were reported to cause or irritate the reported eye symptoms. 

Overall, six of 15 (40.0%) interviewed employees reported nose or sinus symptoms (such as stuffy or 

runny nose), and two of these six (33.3%) employees reported their nose symptoms improved while 

away from work. The only product or task reported to cause or irritate these nose symptoms was 

exposure to acrylics, such as resins used for temporary crowns or dentures.

Discussion 

Dental personnel can be exposed to various agents such as chemicals, dusts, bio-aerosols, and metals as 

part of their normal work duties. We focused our exposure assessment on mercury, respirable dust, 

respirable metals, and VOCs. We also observed work practices and assessed the ventilation systems in 

place as well as the use of PPE. Our observations and results from the exposure assessment are further

discussed below.

Observation of Work Practices, Processes, and Conditions

We observed employees using surgical masks and triple layer molded face masks. The triple layer 

molded face masks are designed to absorb liquids, moisture, and microorganisms. Both types of masks 

are designed for potential exposures to blood and body fluids and are not considered respiratory 

protection because they do not protect against particulate, gas, or vapor exposures in the air.

Exposure Assessment

All personal air sampling measurements for mercury were well below the NIOSH REL. The highest 

measurement of 0.5 μg/m3 mercury was 100-fold lower than the NIOSH REL of 50 μg/m3. Exposure 

to mercury vapor or dust can potentially occur from various sources such as mixing, handling, or 

removing amalgam [Warwick et al. 2019]. 

Because area air samples are not personal air samples collected directly on an employee, the NIOSH 

RELs are not directly applicable to the results for exposure monitoring purposes. However, area air 

samples can highlight areas with higher exposure risk, and the NIOSH RELs can be used as points of 

reference. All area samples for respirable dust, respirable silica, and respirable metals were below their 

respective RELs. We measured some VOCs that were below their respective exposure limits but are 

notable because they are associated with respiratory symptoms at levels below their exposure limits. 

Full-shift TWA measurements from canister samples measured methyl methacrylate at levels ranging 

from 9.3 ppb to 63.8 ppb and styrene at levels ranging from < 2.1 ppb to 46.3 ppb. Instantaneous

measurements collected in the center of the downstairs lab which was no longer in use measured 125.5 
B-7

ppb methyl methacrylate. We note that exposure to methyl methacrylates or styrene in the air can cause 

respiratory irritation and work-related asthma at levels below exposure limits [Lindstrom et al. 2002; 

Jaakkola et al. 2007; Venables and Chan-Yeung 1997; Hayes et al. 1991; Moscato et al. 1987]. Polymers 

and co-polymers of methyl methacrylate are sometimes used in dental prostheses [WHO 1998]. Styrene 

is sometimes used as a dental filling component [NCBI 2020].

Because multiple samples for ethanol and isopropyl alcohol from both sampler types were greater than 

the calibration maximum used by the laboratory performing sample analyses, we cannot interpret 

whether these samples were lower than the NIOSH REL of 1,000 ppm for ethanol or 400 ppm for 

isopropyl alcohol. Ethanol and isopropyl alcohol are chemicals commonly used for cleaning and 

disinfection procedures. 

Ventilation Assessment

The examination rooms, consultation office, and laboratory space were under positive pressure relative 

to adjacent spaces. Positive pressure in the laboratory area could lead to entrainment of air and 

contaminants from the laboratory area into adjacent areas such as the breakroom. Although there are 

no specific ASHRAE guidelines for dental clinics, ANSI/ASHRAE/ASHE Standard 170-2017,

Ventilation of Health Care Facilities, has design parameters for healthcare facilities. ASHRAE recommends 

that laboratory work areas be kept under negative pressure relative to adjacent spaces

[ANSI/ASHRAE/ASHE 2017]. Although all air measurements collected for particulates and vapors 

were relatively low, there is a potential for future exposures or contaminants generated in the laboratory 

area to be entrained into adjacent spaces.

Work-related Symptoms or Conditions

Work-related asthma refers to asthma that is brought on by (“occupational asthma”) or made worse by 

(“work-exacerbated asthma” or “work-aggravated asthma”) workplace exposures [Tarlo 2016; Tarlo and 

Lemiere 2014; OSHA 2014; Henneberger et al. 2011; Venables and Chan-Yeung 1997]. It includes 

asthma due to sensitizers, which cause disease through immune (allergic) mechanisms, and asthma due 

to irritants, which cause disease through non-immune mechanisms. Symptoms of work-related asthma 

include episodic shortness of breath, cough, wheeze, and chest tightness. The symptoms may begin 

early in a work shift, towards the end of a shift, or hours after a shift. They generally, but do not always, 

improve or remit during periods away from work, such as on weekends or holidays.

Methyl methacrylates and styrene exposure are associated with occupational asthma [Lozewics et al.; 

Sánchez-Garcia et al.; Hayes et al.; Moscato et al.; Fernandez-Nieto et al.; AOEC 2012]. It is unknown 

what concentrations of methyl methacrylates or styrene in air can lead to sensitization or asthma, but 

some individuals are more susceptible to developing these illnesses after exposure than others [Venables 

and Chan-Yeung 1997]. Persons who become sensitized (develop an immune reaction) to methyl

methacrylate or styrene can subsequently react to relatively low concentrations in the air.
B-8

Additionally, methyl methacrylates and mercury can cause occupational contact dermatitis in exposed 

skin [Prajapati et al. 2013; Aalto-Korte et al. 2007; ATSDR 2014]. Dermal exposure can be mitigated 

with protective barriers such as gloves when handling products that contain methacrylates or mercury.

Symptoms of high exposure to ethanol or isopropyl alcohol include irritation of the eyes, skin, and 

nose; headache; drowsiness; weakness or dizziness; exhaustion; cough; liver damage; anemia; and 

reproductive effects [NIOSH 2007]. Symptoms of high exposure to acetone include irritation of the 

eyes, skin, nose, throat; headache, dizziness, and central nervous system depression [NIOSH 2007].

Should employees develop symptoms consistent with exposure to any of these compounds, they should 

report new, persistent, or worsening symptoms to their personal healthcare providers, and, as 

instructed, to a designated individual at their workplace.

Limitations 

As described above, because multiple VOC samples were greater than the calibration maximum used by 

the laboratory performing sample analyses, we cannot interpret whether these samples were lower than 

the NIOSH REL of 1000 ppm for ethanol or 400 ppm for isopropyl alcohol.

Conclusions

All personal exposure measurements to mercury vapors were well below the NIOSH REL, and all area 

air samples for respirable dust, respirable silica, and respirable metals were low. Most area VOC samples 

were also low. We noted positive pressure in the laboratory area that could lead to entrainment of air 

and contaminants from the laboratory area into adjacent areas such as the breakroom. Although some 

employees reported eye or nose symptoms, these symptoms in most employees did not appear to be 

work-related. Among the few reported work-related eye or nose symptoms, exposure to acrylics, such 

as resins used for temporary crowns or dentures, was noted as causing or irritating nose symptoms.

Should employees develop symptoms consistent with exposure, they should report new, persistent, or 

worsening symptoms to their personal healthcare providers, and, as instructed, to a designated 

individual at their workplace.
C-1

Section C: Tables

Table C1. Full-shift personal exposures to elemental mercury, June 2019.

Above Minimum Maximum Above 

Analyte Job Title N LOD Concentration Concentration REL N

N (%) (μg/m3) (μg/m3) (%)

Mercury Administrative 9 5 (56%) <0.1 0.5 0 (0%)

Mercury Dental Assistant 21 14 (67%) <0.1 0.2 0 (0%)

Mercury Dental Hygienist 5 3 (60%) <0.1 0.2 0 (0%)

Mercury Dentist 4 3 (75%) <0.1 0.1 0 (0%)

N=number of samples; LOD=limit of detection; REL=NIOSH Recommended Exposure Limit.

Table C2. Full-shift area air measurements of respirable silica (cristobalite, quartz, and tridymite) and 

respirable dust, June 2019.

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (μg/m3) (μg/m3)

Exam Room 0 Cristobalite 3 0 (0%) <3.3 <3.3

Exam Room 0 Respirable dust 3 0 (0%) <13.0 <13.1

Exam Room 0 Quartz 3 0 (0%) <3.3 <3.3

Exam Room 0 Tridymite 3 0 (0%) <6.5 <6.6

Exam Room 1 Cristobalite 3 0 (0%) <3.3 <3.3

Exam Room 1 Respirable dust 3 0 (0%) <13.0 <13.1

Exam Room 1 Quartz 3 0 (0%) <3.3 <3.3

Exam Room 1 Tridymite 3 0 (0%) <6.5 <6.6

Exam Room 2 Cristobalite 3 0 (0%) <3.3 <3.3

Exam Room 2 Respirable dust 3 0 (0%) <13.0 <13.1

Exam Room 2 Quartz 3 0 (0%) <3.3 <3.3

Exam Room 2 Tridymite 3 0 (0%) <6.5 <6.5

Exam Room 3 Cristobalite 3 0 (0%) <3.3 <3.5

Exam Room 3 Respirable dust 3 0 (0%) <13.1 <14.0

Exam Room 3 Quartz 3 0 (0%) <3.3 <3.5

Exam Room 3 Tridymite 3 0 (0%) <6.5 <7.0

Exam Room 4 Cristobalite 3 0 (0%) <3.3 <3.3

Exam Room 4 Respirable dust 3 0 (0%) <13.0 <13.2

Exam Room 4 Quartz 3 0 (0%) <3.3 <3.3
C-2

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (μg/m3) (μg/m3)

Exam Room 4 Tridymite 3 0 (0%) <6.5 <6.6

Exam Room 5 Cristobalite 3 0 (0%) <3.3 <3.3

Exam Room 5 Respirable dust 3 1 (33%) <13.1 17.6

Exam Room 5 Quartz 3 0 (0%) <3.3 <3.3

Exam Room 5 Tridymite 3 0 (0%) <6.5 <6.6

Exam Room 6 Cristobalite 3 0 (0%) <3.3 <3.3

Exam Room 6 Respirable dust 3 0 (0%) <13.1 <13.3

Exam Room 6 Quartz 3 0 (0%) <3.3 <3.3

Exam Room 6 Tridymite 3 0 (0%) <6.6 <6.6

Exam Room 7 Cristobalite 3 0 (0%) <3.2 <3.3

Exam Room 7 Respirable dust 3 0 (0%) <13.0 <13.3

Exam Room 7 Quartz 3 0 (0%) <3.2 <3.3

Exam Room 7 Tridymite 3 0 (0%) <6.5 <6.6

Lab Area Cristobalite 3 0 (0%) <3.3 <3.3

Lab Area Respirable dust 3 0 (0%) <13.1 <13.3

Lab Area Quartz 3 0 (0%) <3.3 <3.3

Lab Area Tridymite 3 0 (0%) <6.5 <6.7

Sterilization Cristobalite 3 0 (0%) <3.3 <3.3

Sterilization Respirable dust 3 0 (0%) <13.1 <13.3

Sterilization Quartz 3 0 (0%) <3.3 <3.3

Sterilization Tridymite 3 0 (0%) <6.6 <6.6

N=number of samples; LOD=limit of detection.
C-3

Table C3. Full-shift area measurements for respirable metals, June 2019.

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (μg/m3) (μg/m3)

Exam Room 0 Aluminum 3 0 (0%) <0.46 <0.59

Exam Room 0 Antimony 3 0 (0%) <0.20 <0.33

Exam Room 0 Arsenic 3 0 (0%) <0.33 <0.39

Exam Room 0 Barium 3 1 (33%) <0.01 0.02

Exam Room 0 Beryllium 3 0 (0%) <0.01 <0.01

Exam Room 0 Cadmium 3 0 (0%) <0.01 <0.02

Exam Room 0 Calcium 3 2 (67%) <=0.79 0.79

Exam Room 0 Chromium 3 3 (100%) 0.32 0.38

Exam Room 0 Cobalt 3 0 (0%) <0.03 <0.03

Exam Room 0 Copper 3 0 (0%) <0.07 <0.20

Exam Room 0 Iron 3 0 (0%) <0.39 <0.66

Exam Room 0 Lanthanum 3 0 (0%) <0.01 <0.01

Exam Room 0 Lead 3 0 (0%) <0.13 <0.20

Exam Room 0 Lithium 3 0 (0%) <0.03 <0.04

Exam Room 0 Magnesium 3 2 (67%) <=0.09 0.118

Exam Room 0 Manganese 3 1 (33%) <=0.01 0.01

Exam Room 0 Molybdenum 3 0 (0%) <0.03 <0.03

Exam Room 0 Nickel 3 0 (0%) <0.03 <0.05

Exam Room 0 Phosphorus 3 1 (33%) <1.31 1.51

Exam Room 0 Potassium 3 3 (100%) 0.48 0.66

Exam Room 0 Selenium 3 0 (0%) <0.53 <1.32

Exam Room 0 Silver 3 0 (0%) <0.01 <0.05

Exam Room 0 Strontium 3 1 (33%) <0.01 0.01

Exam Room 0 Tellurium 3 0 (0%) <0.04 <0.26

Exam Room 0 Thallium 3 0 (0%) <0.13 <0.26

Exam Room 0 Tin 3 1 (33%) <=0.04 0.04

Exam Room 0 Titanium 3 0 (0%) <0.01 <0.01
C-4

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (μg/m3) (μg/m3)

Exam Room 0 Vanadium 3 0 (0%) <0.26 <0.33

Exam Room 0 Yttrium 3 0 (0%) <0.01 <0.01

Exam Room 0 Zinc 3 1 (33%) <0.04 0.04

Exam Room 0 Zirconium 3 0 (0%) <0.01 <0.01

Exam Room 1 Aluminum 3 0 (0%) <0.46 <0.59

Exam Room 1 Antimony 3 0 (0%) <0.20 <0.33

Exam Room 1 Arsenic 3 0 (0%) <0.33 <0.40

Exam Room 1 Barium 3 1 (33%) <0.01 0.02

Exam Room 1 Beryllium 3 0 (0%) <0.01 <0.01

Exam Room 1 Cadmium 3 0 (0%) <0.01 <0.02

Exam Room 1 Calcium 3 1 (33%) <0.65 0.66

Exam Room 1 Chromium 3 2 (67%) <0.13 0.33

Exam Room 1 Cobalt 3 0 (0%) <0.03 <0.03

Exam Room 1 Copper 3 0 (0%) <0.07 <0.20

Exam Room 1 Iron 3 1 (33%) <0.39 1.45

Exam Room 1 Lanthanum 3 0 (0%) <0.01 <0.01

Exam Room 1 Lead 3 0 (0%) <0.13 <0.20

Exam Room 1 Lithium 3 1 (33%) <0.03 0.04

Exam Room 1 Magnesium 3 2 (67%) <=0.09 0.13

Exam Room 1 Manganese 3 1 (33%) <=0.02 0.02

Exam Room 1 Molybdenum 3 0 (0%) <0.03 <0.03

Exam Room 1 Nickel 3 0 (0%) <0.03 <0.05

Exam Room 1 Phosphorus 3 0 (0%) <1.31 <1.32

Exam Room 1 Potassium 3 3 (100%) 0.32 0.73

Exam Room 1 Selenium 3 0 (0%) <0.53 <1.32

Exam Room 1 Silver 3 0 (0%) <0.01 <0.05

Exam Room 1 Strontium 3 0 (0%) <0.01 <0.01

Exam Room 1 Tellurium 3 1 (33%) <=0.07 0.07
C-5

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (μg/m3) (μg/m3)

Exam Room 1 Thallium 3 0 (0%) <0.13 <0.26

Exam Room 1 Tin 3 1 (33%) <=0.06 0.06

Exam Room 1 Titanium 3 1 (33%) <0.01 0.01

Exam Room 1 Vanadium 3 0 (0%) <0.26 <0.33

Exam Room 1 Yttrium 3 0 (0%) <0.01 <0.01

Exam Room 1 Zinc 3 1 (33%) <0.04 0.08

Exam Room 1 Zirconium 3 0 (0%) <0.01 <0.01

Exam Room 2 Aluminum 3 0 (0%) <0.46 <0.59

Exam Room 2 Antimony 3 0 (0%) <0.20 <0.33

Exam Room 2 Arsenic 3 0 (0%) <0.33 <0.40

Exam Room 2 Barium 3 2 (67%) <0.01 0.02

Exam Room 2 Beryllium 3 0 (0%) <0.01 <0.01

Exam Room 2 Cadmium 3 0 (0%) <0.01 <0.02

Exam Room 2 Calcium 3 2 (67%) <=0.86 0.99

Exam Room 2 Chromium 3 3 (100%) 0.30 0.38

Exam Room 2 Cobalt 3 0 (0%) <0.03 <0.03

Exam Room 2 Copper 3 1 (33%) <0.07 0.20

Exam Room 2 Iron 3 0 (0%) <0.40 <0.66

Exam Room 2 Lanthanum 3 0 (0%) <0.01 <0.01

Exam Room 2 Lead 3 0 (0%) <0.13 <0.20

Exam Room 2 Lithium 3 0 (0%) <0.03 <0.04

Exam Room 2 Magnesium 3 2 (67%) <=0.12 0.13

Exam Room 2 Manganese 3 2 (67%) <=0.02 0.38

Exam Room 2 Molybdenum 3 0 (0%) <0.03 <0.03

Exam Room 2 Nickel 3 0 (0%) <0.03 <0.05

Exam Room 2 Phosphorus 3 1 (33%) <1.31 1.71

Exam Room 2 Potassium 3 3 (100%) 0.51 0.57

Exam Room 2 Selenium 3 0 (0%) <0.53 <1.32
C-6

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (μg/m3) (μg/m3)

Exam Room 2 Silver 3 0 (0%) <0.01 <0.05

Exam Room 2 Strontium 3 1 (33%) <0.01 0.01

Exam Room 2 Tellurium 3 0 (0%) <0.05 <0.26

Exam Room 2 Thallium 3 0 (0%) <0.13 <0.26

Exam Room 2 Tin 3 0 (0%) <0.03 <0.20

Exam Room 2 Titanium 3 0 (0%) <0.01 <0.01

Exam Room 2 Vanadium 3 0 (0%) <0.26 <0.33

Exam Room 2 Yttrium 3 0 (0%) <0.01 <0.01

Exam Room 2 Zinc 3 1 (33%) <0.04 0.20

Exam Room 2 Zirconium 3 0 (0%) <0.01 <0.01

Exam Room 3 Aluminum 3 1 (33%) <0.59 0.61

Exam Room 3 Antimony 3 0 (0%) <0.20 <0.33

Exam Room 3 Arsenic 3 0 (0%) <0.33 <0.40

Exam Room 3 Barium 3 2 (67%) <0.01 0.07

Exam Room 3 Beryllium 3 0 (0%) <0.01 <0.01

Exam Room 3 Cadmium 3 0 (0%) <0.01 <0.02

Exam Room 3 Calcium 3 1 (33%) <0.65 1.06

Exam Room 3 Chromium 3 3 (100%) 0.22 0.42

Exam Room 3 Cobalt 3 0 (0%) <0.03 <0.03

Exam Room 3 Copper 3 0 (0%) <0.07 <0.20

Exam Room 3 Iron 3 0 (0%) <0.39 <0.66

Exam Room 3 Lanthanum 3 0 (0%) <0.01 <0.01

Exam Room 3 Lead 3 0 (0%) <0.13 <0.20

Exam Room 3 Lithium 3 0 (0%) <0.03 <0.04

Exam Room 3 Magnesium 3 2 (67%) <=0.11 0.13

Exam Room 3 Manganese 3 1 (33%) <=0.02 0.02

Exam Room 3 Molybdenum 3 0 (0%) <0.03 <0.03

Exam Room 3 Nickel 3 1 (33%) <0.03 0.13
C-7

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (μg/m3) (μg/m3)

Exam Room 3 Phosphorus 3 0 (0%) <1.31 <1.32

Exam Room 3 Potassium 3 3 (100%) 0.72 1.59

Exam Room 3 Selenium 3 0 (0%) <0.53 <1.32

Exam Room 3 Silver 3 0 (0%) <0.01 <0.05

Exam Room 3 Strontium 3 1 (33%) <0.01 0.01

Exam Room 3 Tellurium 3 0 (0%) <0.05 <0.26

Exam Room 3 Thallium 3 0 (0%) <0.13 <0.26

Exam Room 3 Tin 3 0 (0%) <0.03 <0.20

Exam Room 3 Titanium 3 1 (33%) <0.01 0.01

Exam Room 3 Vanadium 3 0 (0%) <0.26 <0.33

Exam Room 3 Yttrium 3 0 (0%) <0.01 <0.01

Exam Room 3 Zinc 3 1 (33%) <0.04 0.09

Exam Room 3 Zirconium 3 1 (33%) <0.01 0.03

Exam Room 4 Aluminum 3 0 (0%) <0.46 <0.60

Exam Room 4 Antimony 3 0 (0%) <0.20 <0.33

Exam Room 4 Arsenic 3 0 (0%) <0.33 <0.40

Exam Room 4 Barium 3 1 (33%) <0.01 0.02

Exam Room 4 Beryllium 3 0 (0%) <0.01 <0.01

Exam Room 4 Cadmium 3 0 (0%) <0.01 <0.02

Exam Room 4 Calcium 3 2 (67%) <=0.92 0.99

Exam Room 4 Chromium 3 3 (100%) 0.32 0.33

Exam Room 4 Cobalt 3 0 (0%) <0.03 <0.03

Exam Room 4 Copper 3 0 (0%) <0.07 <0.20

Exam Room 4 Iron 3 0 (0%) <0.39 <0.66

Exam Room 4 Lanthanum 3 0 (0%) <0.01 <0.01

Exam Room 4 Lead 3 0 (0%) <0.13 <0.20

Exam Room 4 Lithium 3 0 (0%) <0.03 <0.04

Exam Room 4 Magnesium 3 2 (67%) <=0.10 0.14
C-8

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (μg/m3) (μg/m3)

Exam Room 4 Manganese 3 1 (33%) <=0.07 0.07

Exam Room 4 Molybdenum 3 0 (0%) <0.03 <0.03

Exam Room 4 Nickel 3 0 (0%) <0.03 <0.05

Exam Room 4 Phosphorus 3 0 (0%) <1.31 <1.32

Exam Room 4 Potassium 3 3 (100%) 0.66 0.99

Exam Room 4 Selenium 3 0 (0%) <0.53 <1.32

Exam Room 4 Silver 3 0 (0%) <0.01 <0.05

Exam Room 4 Strontium 3 1 (33%) <0.01 0.01

Exam Room 4 Tellurium 3 0 (0%) <0.05 <0.26

Exam Room 4 Thallium 3 0 (0%) <0.13 <0.26

Exam Room 4 Tin 3 0 (0%) <0.03 <0.20

Exam Room 4 Titanium 3 0 (0%) <0.01 <0.01

Exam Room 4 Vanadium 3 0 (0%) <0.26 <0.33

Exam Room 4 Yttrium 3 1 (33%) <0.01 0.01

Exam Room 4 Zinc 3 2 (67%) <0.04 0.08

Exam Room 4 Zirconium 3 0 (0%) <0.01 <0.01

Exam Room 5 Aluminum 3 0 (0%) <0.46 <0.59

Exam Room 5 Antimony 3 0 (0%) <0.20 <0.33

Exam Room 5 Arsenic 3 0 (0%) <0.33 <0.40

Exam Room 5 Barium 3 2 (67%) <0.01 0.02

Exam Room 5 Beryllium 3 0 (0%) <0.01 <0.01

Exam Room 5 Cadmium 3 0 (0%) <0.01 <0.02

Exam Room 5 Calcium 3 1 (33%) <0.66 1.45

Exam Room 5 Chromium 3 3 (100%) 0.24 0.35

Exam Room 5 Cobalt 3 0 (0%) <0.03 <0.03

Exam Room 5 Copper 3 0 (0%) <0.07 <0.20

Exam Room 5 Iron 3 0 (0%) <0.39 <0.66

Exam Room 5 Lanthanum 3 1 (33%) <0.01 0.01
C-9

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (μg/m3) (μg/m3)

Exam Room 5 Lead 3 0 (0%) <0.13 <0.20

Exam Room 5 Lithium 3 0 (0%) <0.03 <0.04

Exam Room 5 Magnesium 3 2 (67%) <=0.09 0.13

Exam Room 5 Manganese 3 1 (33%) <=0.02 0.02

Exam Room 5 Molybdenum 3 0 (0%) <0.03 <0.03

Exam Room 5 Nickel 3 1 (33%) <0.03 0.15

Exam Room 5 Phosphorus 3 0 (0%) <1.31 <1.32

Exam Room 5 Potassium 3 3 (100%) 0.55 1.19

Exam Room 5 Selenium 3 0 (0%) <0.53 <1.32

Exam Room 5 Silver 3 0 (0%) <0.01 <0.05

Exam Room 5 Strontium 3 0 (0%) <0.01 <0.01

Exam Room 5 Tellurium 3 0 (0%) <0.05 <0.26

Exam Room 5 Thallium 3 0 (0%) <0.13 <0.26

Exam Room 5 Tin 3 0 (0%) <0.03 <0.20

Exam Room 5 Titanium 3 0 (0%) <0.01 <0.01

Exam Room 5 Vanadium 3 0 (0%) <0.26 <0.33

Exam Room 5 Yttrium 3 0 (0%) <0.01 <0.01

Exam Room 5 Zinc 3 3 (100%) 0.05 0.10

Exam Room 5 Zirconium 3 0 (0%) <0.01 <0.01

Exam Room 6 Aluminum 3 0 (0%) <0.46 <0.60

Exam Room 6 Antimony 3 0 (0%) <0.20 <0.33

Exam Room 6 Arsenic 3 0 (0%) <0.33 <0.40

Exam Room 6 Barium 3 3 (100%) 0.01 0.02

Exam Room 6 Beryllium 3 0 (0%) <0.01 <0.01

Exam Room 6 Cadmium 3 0 (0%) <0.01 <0.02

Exam Room 6 Calcium 3 2 (67%) <=0.66 0.80

Exam Room 6 Chromium 3 3 (100%) 0.25 0.49

Exam Room 6 Cobalt 3 0 (0%) <0.03 <0.03
C-10

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (μg/m3) (μg/m3)

Exam Room 6 Copper 3 2 (67%) <0.20 2.38

Exam Room 6 Iron 3 0 (0%) <0.40 <0.66

Exam Room 6 Lanthanum 3 0 (0%) <0.01 <0.01

Exam Room 6 Lead 3 0 (0%) <0.13 <0.199

Exam Room 6 Lithium 3 0 (0%) <0.03 <0.04

Exam Room 6 Magnesium 3 2 (67%) <=0.11 0.15

Exam Room 6 Manganese 3 2 (67%) <0.27 4.43

Exam Room 6 Molybdenum 3 0 (0%) <0.03 <0.03

Exam Room 6 Nickel 3 1 (33%) <0.03 0.03

Exam Room 6 Phosphorus 3 0 (0%) <1.32 <1.33

Exam Room 6 Potassium 3 3 (100%) 0.53 1.38

Exam Room 6 Selenium 3 0 (0%) <0.53 <1.33

Exam Room 6 Silver 3 0 (0%) <0.01 <0.05

Exam Room 6 Strontium 3 1 (33%) <0.01 0.01

Exam Room 6 Tellurium 3 0 (0%) <0.05 <0.27

Exam Room 6 Thallium 3 0 (0%) <0.13 <0.26

Exam Room 6 Tin 3 0 (0%) <0.03 <0.20

Exam Room 6 Titanium 3 0 (0%) <0.01 <0.01

Exam Room 6 Vanadium 3 0 (0%) <0.26 <0.33

Exam Room 6 Yttrium 3 0 (0%) <0.01 <0.01

Exam Room 6 Zinc 3 2 (67%) <0.04 0.06

Exam Room 6 Zirconium 3 0 (0%) <0.01 <0.01

Exam Room 7 Aluminum 3 0 (0%) <0.46 <0.60

Exam Room 7 Antimony 3 1 (33%) <=0.21 0.21

Exam Room 7 Arsenic 3 0 (0%) <0.33 <0.40

Exam Room 7 Barium 3 2 (67%) <0.01 0.04

Exam Room 7 Beryllium 3 0 (0%) <0.01 <0.01

Exam Room 7 Cadmium 3 1 (33%) <=0.02 0.02
C-11

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (μg/m3) (μg/m3)

Exam Room 7 Calcium 3 2 (67%) <=1.45 1.59

Exam Room 7 Chromium 3 3 (100%) 0.31 0.39

Exam Room 7 Cobalt 3 0 (0%) <0.03 <0.03

Exam Room 7 Copper 3 1 (33%) <0.07 0.45

Exam Room 7 Iron 3 0 (0%) <0.40 <0.66

Exam Room 7 Lanthanum 3 0 (0%) <0.01 <0.01

Exam Room 7 Lead 3 0 (0%) <0.13 <0.20

Exam Room 7 Lithium 3 1 (33%) <0.03 0.04

Exam Room 7 Magnesium 3 2 (67%) <=0.12 0.15

Exam Room 7 Manganese 3 2 (67%) <=0.02 0.80

Exam Room 7 Molybdenum 3 0 (0%) <0.03 <0.03

Exam Room 7 Nickel 3 0 (0%) <0.03 <0.05

Exam Room 7 Phosphorus 3 0 (0%) <1.32 <1.33

Exam Room 7 Potassium 3 3 (100%) 0.49 0.73

Exam Room 7 Selenium 3 0 (0%) <0.53 <1.31

Exam Room 7 Silver 3 0 (0%) <0.01 <0.05

Exam Room 7 Strontium 3 1 (33%) <0.01 0.01

Exam Room 7 Tellurium 3 1 (33%) <=0.06 0.06

Exam Room 7 Thallium 3 0 (0%) <0.13 <0.27

Exam Room 7 Tin 3 1 (33%) <=0.03 0.03

Exam Room 7 Titanium 3 0 (0%) <0.01 <0.01

Exam Room 7 Vanadium 3 0 (0%) <0.27 <0.33

Exam Room 7 Yttrium 3 0 (0%) <0.01 <0.01

Exam Room 7 Zinc 3 3 (100%) 0.05 2.11

Exam Room 7 Zirconium 3 0 (0%) <0.01 <0.01

Lab Area Aluminum 3 0 (0%) <0.46 <0.60

Lab Area Antimony 3 0 (0%) <0.20 <0.33

Lab Area Arsenic 3 0 (0%) <0.33 <0.40
C-12

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (μg/m3) (μg/m3)

Lab Area Barium 3 3 (100%) 0.01 0.02

Lab Area Beryllium 3 0 (0%) <0.01 <0.01

Lab Area Cadmium 3 0 (0%) <0.01 <0.02

Lab Area Calcium 3 1 (33%) <0.66 0.80

Lab Area Chromium 3 3 (100%) 0.20 0.41

Lab Area Cobalt 3 0 (0%) <0.03 <0.03

Lab Area Copper 3 0 (0%) <0.07 <0.20

Lab Area Iron 3 0 (0%) <0.40 <0.66

Lab Area Lanthanum 3 0 (0%) <0.01 <0.007

Lab Area Lead 3 0 (0%) <0.13 <0.20

Lab Area Lithium 3 0 (0%) <0.03 <0.04

Lab Area Magnesium 3 2 (67%) <=0.11 0.14

Lab Area Manganese 3 1 (33%) <=0.09 0.09

Lab Area Molybdenum 3 0 (0%) <0.03 <0.03

Lab Area Nickel 3 0 (0%) <0.03 <0.05

Lab Area Phosphorus 3 0 (0%) <1.32 <1.33

Lab Area Potassium 3 3 (100%) 0.36 1.19

Lab Area Selenium 3 0 (0%) <0.53 <1.33

Lab Area Silver 3 0 (0%) <0.01 <0.05

Lab Area Strontium 3 0 (0%) <0.01 <0.01

Lab Area Tellurium 3 1 (33%) <=0.09 0.09

Lab Area Thallium 3 0 (0%) <0.13 <0.26

Lab Area Tin 3 1 (33%) <=0.09 0.09

Lab Area Titanium 3 0 (0%) <0.01 <0.01

Lab Area Vanadium 3 0 (0%) <0.26 <0.33

Lab Area Yttrium 3 0 (0%) <0.01 <0.01

Lab Area Zinc 3 2 (67%) <0.04 0.06

Lab Area Zirconium 3 0 (0%) <0.01 <0.01
C-13

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (μg/m3) (μg/m3)

Sterilization Aluminum 3 0 (0%) <0.46 <0.60

Sterilization Antimony 3 0 (0%) <0.20 <0.33

Sterilization Arsenic 3 0 (0%) <0.33 <0.40

Sterilization Barium 3 2 (67%) <0.01 0.02

Sterilization Beryllium 3 0 (0%) <0.01 <0.01

Sterilization Cadmium 3 0 (0%) <0.01 <0.02

Sterilization Calcium 3 2 (67%) <=0.86 1.12

Sterilization Chromium 3 3 (100%) 0.22 0.32

Sterilization Cobalt 3 0 (0%) <0.03 <0.03

Sterilization Copper 3 1 (33%) <0.07 0.36

Sterilization Iron 3 0 (0%) <0.40 <0.66

Sterilization Lanthanum 3 0 (0%) <0.01 <0.01

Sterilization Lead 3 0 (0%) <0.13 <0.20

Sterilization Lithium 3 0 (0%) <0.03 <0.04

Sterilization Magnesium 3 2 (67%) <=0.08 0.11

Sterilization Manganese 3 2 (67%) <=0.02 0.66

Sterilization Molybdenum 3 0 (0%) <0.03 <0.03

Sterilization Nickel 3 1 (33%) <0.03 0.07

Sterilization Phosphorus 3 1 (33%) <1.32 1.46

Sterilization Potassium 3 3 (100%) 0.26 0.99

Sterilization Selenium 3 0 (0%) <0.53 <1.33

Sterilization Silver 3 0 (0%) <0.01 <0.05

Sterilization Strontium 3 1 (33%) <0.01 0.01

Sterilization Tellurium 3 0 (0%) <0.05 <0.27

Sterilization Thallium 3 0 (0%) <0.13 <0.26

Sterilization Tin 3 0 (0%) <0.03 <0.20

Sterilization Titanium 3 0 (0%) <0.01 <0.01

Sterilization Vanadium 3 0 (0%) <0.26 <0.33
C-14

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (μg/m3) (μg/m3)

Sterilization Yttrium 3 0 (0%) <0.01 <0.01

Sterilization Zinc 3 1 (33%) <0.04 0.17

Sterilization Zirconium 3 0 (0%) <0.01 <0.01

N=number of samples; LOD=limit of detection.
C-15

Table C4. Full-shift canister area measurements of volatile organic compounds, June 2019.

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (PPB) (PPB)

Administrative 2,3-Butanedione 3 1 (33%) <2.3 3.0

Administrative 2,3-Hexanedione 3 1 (33%) <3.5 5.0

Administrative 2,3-Pentanedione 3 0 (0%) <2.4 <2.5

Administrative Acetaldehyde 3 0 (0%) <4.7 <4.8

Administrative Acetone 3 3 (100%) 101.1 109.9

Administrative Acetonitrile 3 0 (0%) <6.3 <6.5

Administrative Benzene 3 3 (100%) 3.4 3.5

Administrative Chloroform 3 0 (0%) <0.1 <0.1

Administrative D-Limonene 3 3 (100%) 2.6 4.1

Administrative Ethanol 3 3 (100%) 2116.9 2829.7

Administrative Ethylbenzene 3 0 (0%) <1.4 <1.4

Administrative Isopropyl Alcohol 3 3 (100%) ─ ─

Administrative Methyl Methacrylate 3 3 (100%) 9.5 10.4

Administrative Methylene Chloride 3 0 (0%) <0.4 <0.4

Administrative Styrene 3 1 (33%) <2.1 6.4

Administrative Toluene 3 3 (100%) 5.0 5.1

Administrative alpha-Pinene 3 0 (0%) <1.5 <1.6

Administrative m,p-Xylene 3 3 (100%) 2.6 2.7

Administrative n-Hexane 3 3 (100%) 6.4 24.5

Administrative o-Xylene 3 1 (33%) <0.6 2.0

Exam Room 0 2,3-Butanedione 3 0 (0%) <2.3 <23.6

Exam Room 0 2,3-Hexanedione 3 0 (0%) <3.4 <35.7

Exam Room 0 2,3-Pentanedione 3 0 (0%) <2.4 <24.6

Exam Room 0 Acetaldehyde 3 0 (0%) <4.6 <48.0

Exam Room 0 Acetone 3 3 (100%) 112.2 170.9

Exam Room 0 Acetonitrile 3 0 (0%) <6.2 <6.5

Exam Room 0 Benzene 3 3 (100%) 3.5 34.3

Exam Room 0 Chloroform 3 0 (0%) <0.1 <1.1

Exam Room 0 D-Limonene 3 3 (100%) 3.5 52.2

Exam Room 0 Ethanol 3 3 (100%) 2749.0 ─

Exam Room 0 Ethylbenzene 3 1 (33%) <1.4 25.2

Exam Room 0 Isopropyl Alcohol 3 3 (100%) ─ ─

Exam Room 0 Methyl Methacrylate 3 3 (100%) 10.2 63.8
C-16

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (PPB) (PPB)

Exam Room 0 Methylene Chloride 3 0 (0%) <0.4 <3.9

Exam Room 0 Styrene 3 3 (100%) 4.6 46.3

Exam Room 0 Toluene 3 2 (67%) <2.0 48.3

Exam Room 0 alpha-Pinene 3 0 (0%) <1.5 <15.5

Exam Room 0 m,p-Xylene 3 3 (100%) 2.5 24.8

Exam Room 0 n-Hexane 3 3 (100%) 24.2 31.8

Exam Room 0 o-Xylene 3 2 (67%) <0.6 18.8

Exam Room 1 2,3-Butanedione 3 0 (0%) <2.3 <2.3

Exam Room 1 2,3-Hexanedione 3 0 (0%) <3.5 <3.6

Exam Room 1 2,3-Pentanedione 3 0 (0%) <2.4 <2.4

Exam Room 1 Acetaldehyde 3 0 (0%) <4.7 <4.8

Exam Room 1 Acetone 3 3 (100%) 129.0 172.3

Exam Room 1 Acetonitrile 3 0 (0%) <6.3 <6.5

Exam Room 1 Benzene 3 3 (100%) 3.4 3.6

Exam Room 1 Chloroform 3 1 (33%) <0.1 1.4

Exam Room 1 D-Limonene 3 3 (100%) 2.8 6.6

Exam Room 1 Ethanol 3 3 (100%) 2899.2 ─

Exam Room 1 Ethylbenzene 3 0 (0%) <1.4 <1.4

Exam Room 1 Isopropyl Alcohol 3 3 (100%) ─ ─

Exam Room 1 Methyl Methacrylate 3 3 (100%) 10.3 11.3

Exam Room 1 Methylene Chloride 3 0 (0%) <0.4 <0.4

Exam Room 1 Styrene 3 2 (67%) <2.2 4.6

Exam Room 1 Toluene 3 2 (67%) <2.0 5.3

Exam Room 1 alpha-Pinene 3 0 (0%) <1.5 <1.5

Exam Room 1 m,p-Xylene 3 3 (100%) 2.6 2.9

Exam Room 1 n-Hexane 3 3 (100%) 7.0 32.3

Exam Room 1 o-Xylene 3 1 (33%) <0.6 2.1

Exam Room 2 2,3-Butanedione 3 0 (0%) <2.3 <2.3

Exam Room 2 2,3-Hexanedione 3 0 (0%) <3.4 <3.5

Exam Room 2 2,3-Pentanedione 3 0 (0%) <2.4 <2.4

Exam Room 2 Acetaldehyde 3 0 (0%) <4.6 <4.8

Exam Room 2 Acetone 3 3 (100%) 119.0 133.3

Exam Room 2 Acetonitrile 3 0 (0%) <6.3 <6.4

Exam Room 2 Benzene 3 3 (100%) 3.4 6.2
C-17

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (PPB) (PPB)

Exam Room 2 Chloroform 3 0 (0%) <0.1 <0.1

Exam Room 2 D-Limonene 3 3 (100%) 2.7 3.6

Exam Room 2 Ethanol 3 3 (100%) 2598.0 ─

Exam Room 2 Ethylbenzene 3 0 (0%) <1.4 <1.4

Exam Room 2 Isopropyl Alcohol 3 3 (100%) ─ ─

Exam Room 2 Methyl Methacrylate 3 3 (100%) 9.5 10.9

Exam Room 2 Methylene Chloride 3 0 (0%) <0.4 <0.4

Exam Room 2 Styrene 3 1 (33%) <2.1 4.6

Exam Room 2 Toluene 3 3 (100%) 4.9 5.0

Exam Room 2 alpha-Pinene 3 0 (0%) <1.5 <1.5

Exam Room 2 m,p-Xylene 3 3 (100%) 2.6 2.6

Exam Room 2 n-Hexane 3 3 (100%) 6.8 29.1

Exam Room 2 o-Xylene 3 1 (33%) <0.6 2.0

Exam Room 3 2,3-Butanedione 3 0 (0%) <2.2 <2.3

Exam Room 3 2,3-Hexanedione 3 1 (33%) <3.4 5.5

Exam Room 3 2,3-Pentanedione 3 0 (0%) <2.3 <2.4

Exam Room 3 Acetaldehyde 3 0 (0%) <4.6 <4.7

Exam Room 3 Acetone 3 3 (100%) 105.6 743.9

Exam Room 3 Acetonitrile 3 0 (0%) <6.2 <6.4

Exam Room 3 Benzene 3 3 (100%) 3.3 3.6

Exam Room 3 Chloroform 3 0 (0%) <0.1 <0.1

Exam Room 3 D-Limonene 3 3 (100%) 2.9 6.5

Exam Room 3 Ethanol 3 3 (100%) 2358.8 ─

Exam Room 3 Ethylbenzene 3 0 (0%) <1.4 <1.4

Exam Room 3 Isopropyl Alcohol 3 3 (100%) ─ ─

Exam Room 3 Methyl Methacrylate 3 3 (100%) 10.2 11.0

Exam Room 3 Methylene Chloride 3 0 (0%) <0.4 <0.4

Exam Room 3 Styrene 3 2 (67%) <2.1 4.7

Exam Room 3 Toluene 3 2 (67%) <2.1 5.1

Exam Room 3 alpha-Pinene 3 0 (0%) <1.5 <1.5

Exam Room 3 m,p-Xylene 3 3 (100%) 2.6 2.7

Exam Room 3 n-Hexane 3 3 (100%) 6.6 30.0

Exam Room 3 o-Xylene 3 1 (33%) <0.6 2.0

Exam Room 4 2,3-Butanedione 3 0 (0%) <2.2 <2.4
C-18

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (PPB) (PPB)

Exam Room 4 2,3-Hexanedione 3 0 (0%) <3.4 <3.6

Exam Room 4 2,3-Pentanedione 3 0 (0%) <2.3 <2.5

Exam Room 4 Acetaldehyde 3 0 (0%) <4.6 <4.8

Exam Room 4 Acetone 3 3 (100%) 111.9 187.2

Exam Room 4 Acetonitrile 3 0 (0%) <6.2 <6.5

Exam Room 4 Benzene 3 2 (67%) <1.2 3.4

Exam Room 4 Chloroform 3 0 (0%) <0.1 <0.1

Exam Room 4 D-Limonene 3 3 (100%) 2.6 6.9

Exam Room 4 Ethanol 3 3 (100%) 2519.1 ─

Exam Room 4 Ethylbenzene 3 0 (0%) <1.4 <1.4

Exam Room 4 Isopropyl Alcohol 3 3 (100%) ─ ─

Exam Room 4 Methyl Methacrylate 3 3 (100%) 9.3 11.1

Exam Room 4 Methylene Chloride 3 0 (0%) <0.4 <0.4

Exam Room 4 Styrene 3 2 (67%) <2.1 4.8

Exam Room 4 Toluene 3 2 (67%) <2.1 5.0

Exam Room 4 alpha-Pinene 3 0 (0%) <1.5 <1.6

Exam Room 4 m,p-Xylene 3 3 (100%) 2.5 2.6

Exam Room 4 n-Hexane 3 3 (100%) 8.2 38.7

Exam Room 4 o-Xylene 3 1 (33%) <0.6 2.0

Exam Room 5 2,3-Butanedione 3 0 (0%) <2.3 <22.7

Exam Room 5 2,3-Hexanedione 3 0 (0%) <3.5 <34.4

Exam Room 5 2,3-Pentanedione 3 0 (0%) <2.4 <23.7

Exam Room 5 Acetaldehyde 3 0 (0%) <4.7 <46.2

Exam Room 5 Acetone 3 3 (100%) 117.8 174.0

Exam Room 5 Acetonitrile 3 0 (0%) <6.2 <6.4

Exam Room 5 Benzene 3 2 (67%) <1.2 33.1

Exam Room 5 Chloroform 3 0 (0%) <0.1 <1.0

Exam Room 5 D-Limonene 3 3 (100%) 2.8 50.3

Exam Room 5 Ethanol 3 3 (100%) 2526.4 ─

Exam Room 5 Ethylbenzene 3 0 (0%) <1.4 <13.7

Exam Room 5 Isopropyl Alcohol 3 3 (100%) ─ ─

Exam Room 5 Methyl Methacrylate 3 3 (100%) 10.4 61.2

Exam Room 5 Methylene Chloride 3 0 (0%) <0.4 <3.7

Exam Room 5 Styrene 3 1 (33%) <2.2 21.1
C-19

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (PPB) (PPB)

Exam Room 5 Toluene 3 3 (100%) 5.0 46.5

Exam Room 5 alpha-Pinene 3 0 (0%) <1.5 <14.9

Exam Room 5 m,p-Xylene 3 2 (67%) <=2.6 11.9

Exam Room 5 n-Hexane 3 3 (100%) 8.1 41.4

Exam Room 5 o-Xylene 3 1 (33%) <0.6 5.7

Exam Room 6 2,3-Butanedione 3 0 (0%) <2.2 <2.4

Exam Room 6 2,3-Hexanedione 3 0 (0%) <3.4 <3.7

Exam Room 6 2,3-Pentanedione 3 0 (0%) <2.3 <2.5

Exam Room 6 Acetaldehyde 3 0 (0%) <4.5 <4.9

Exam Room 6 Acetone 3 3 (100%) 128.1 174.4

Exam Room 6 Acetonitrile 3 0 (0%) <6.1 <6.6

Exam Room 6 Benzene 3 2 (67%) <1.3 3.6

Exam Room 6 Chloroform 3 1 (33%) <0.1 1.3

Exam Room 6 D-Limonene 3 3 (100%) 3.7 6.7

Exam Room 6 Ethanol 3 3 (100%) 2814.2 ─

Exam Room 6 Ethylbenzene 3 0 (0%) <1.3 <1.5

Exam Room 6 Isopropyl Alcohol 3 3 (100%) ─ ─

Exam Room 6 Methyl Methacrylate 3 3 (100%) 10.4 11.3

Exam Room 6 Methylene Chloride 3 0 (0%) <0.4 <0.4

Exam Room 6 Styrene 3 2 (67%) <2.2 4.8

Exam Room 6 Toluene 3 1 (33%) <2.0 5.3

Exam Room 6 alpha-Pinene 3 0 (0%) <1.5 <1.6

Exam Room 6 m,p-Xylene 3 3 (100%) 2.5 2.8

Exam Room 6 n-Hexane 3 3 (100%) 8.1 38.8

Exam Room 6 o-Xylene 3 0 (0%) <0.6 <0.6

Exam Room 7 2,3-Butanedione 3 0 (0%) <2.3 <2.3

Exam Room 7 2,3-Hexanedione 3 0 (0%) <3.4 <3.6

Exam Room 7 2,3-Pentanedione 3 0 (0%) <2.3 <2.5

Exam Room 7 Acetaldehyde 3 0 (0%) <4.6 <4.8

Exam Room 7 Acetone 3 3 (100%) 117.7 157.9

Exam Room 7 Acetonitrile 3 0 (0%) <6.2 <6.5

Exam Room 7 Benzene 3 2 (67%) <1.2 3.5

Exam Room 7 Chloroform 3 0 (0%) <0.1 <0.1

Exam Room 7 D-Limonene 3 3 (100%) 2.8 6.3
C-20

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (PPB) (PPB)

Exam Room 7 Ethanol 3 3 (100%) 2664.5 ─

Exam Room 7 Ethylbenzene 3 0 (0%) <1.4 <1.4

Exam Room 7 Isopropyl Alcohol 3 3 (100%) ─ ─

Exam Room 7 Methyl Methacrylate 3 3 (100%) 10.0 11.0

Exam Room 7 Methylene Chloride 3 0 (0%) <0.4 <0.4

Exam Room 7 Styrene 3 1 (33%) <2.1 4.7

Exam Room 7 Toluene 3 2 (67%) <2.0 5.1

Exam Room 7 alpha-Pinene 3 0 (0%) <1.5 <1.5

Exam Room 7 m,p-Xylene 3 3 (100%) 2.6 2.7

Exam Room 7 n-Hexane 3 3 (100%) 7.8 42.1

Exam Room 7 o-Xylene 3 1 (33%) <0.6 2.0

Lab Area 2,3-Butanedione 3 0 (0%) <2.3 <2.3

Lab Area 2,3-Hexanedione 3 0 (0%) <3.4 <3.5

Lab Area 2,3-Pentanedione 3 0 (0%) <2.4 <2.4

Lab Area Acetaldehyde 3 0 (0%) <4.6 <4.7

Lab Area Acetone 3 3 (100%) 113.9 140.5

Lab Area Acetonitrile 3 0 (0%) <6.2 <6.4

Lab Area Benzene 3 2 (67%) <1.2 3.5

Lab Area Chloroform 3 1 (33%) <0.1 1.3

Lab Area D-Limonene 3 3 (100%) 2.8 6.4

Lab Area Ethanol 3 3 (100%) 2395.9 2791.1

Lab Area Ethylbenzene 3 0 (0%) <1.4 <1.4

Lab Area Isopropyl Alcohol 3 3 (100%) ─ ─

Lab Area Methyl Methacrylate 3 3 (100%) 10.4 10.5

Lab Area Methylene Chloride 3 0 (0%) <0.4 <0.4

Lab Area Styrene 3 2 (67%) <2.1 4.6

Lab Area Toluene 3 2 (67%) <2.0 5.1

Lab Area alpha-Pinene 3 0 (0%) <1.5 <1.5

Lab Area m,p-Xylene 3 3 (100%) 2.6 2.8

Lab Area n-Hexane 3 3 (100%) 7.3 40.4

Lab Area o-Xylene 3 1 (33%) <0.6 2.0

Sterilization 2,3-Butanedione 3 1 (33%) <2.3 3.0

Sterilization 2,3-Hexanedione 3 0 (0%) <3.4 <3.5

Sterilization 2,3-Pentanedione 3 0 (0%) <2.3 <2.4
C-21

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (PPB) (PPB)

Sterilization Acetaldehyde 3 0 (0%) <4.6 <4.7

Sterilization Acetone 3 3 (100%) 115.1 165.0

Sterilization Acetonitrile 3 0 (0%) <6.2 <6.4

Sterilization Benzene 3 2 (67%) <1.2 3.6

Sterilization Chloroform 3 2 (67%) <0.1 1.6

Sterilization D-Limonene 3 3 (100%) 2.8 8.0

Sterilization Ethanol 3 3 (100%) 2712.2 ─

Sterilization Ethylbenzene 3 0 (0%) <1.4 <1.4

Sterilization Isopropyl Alcohol 3 3 (100%) ─ ─

Sterilization Methyl Methacrylate 3 3 (100%) 9.5 10.7

Sterilization Methylene Chloride 3 0 (0%) <0.4 <0.4

Sterilization Styrene 3 1 (33%) <2.1 4.7

Sterilization Toluene 3 2 (67%) <2.1 5.1

Sterilization alpha-Pinene 3 0 (0%) <1.5 <1.5

Sterilization m,p-Xylene 3 3 (100%) 2.6 3.2

Sterilization n-Hexane 3 3 (100%) 7.5 62.3

Sterilization o-Xylene 3 1 (33%) <0.6 2.4

N=number of samples; LOD=limit of detection; PPB=Parts per billion; “─”indicates measurements 

above the calibration maximum.
C-22

Table C5. Full-shift thermal desorption tube area measurements of volatile organic compounds, June 

2019.

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (PPB) (PPB)

Administrative 2,3-Butanedione 3 0 (0%) <1.7 <1.8

Administrative 2,3-Hexanedione 3 0 (0%) <1.4 <1.5

Administrative 2,3-Pentanedione 3 0 (0%) <1.6 <1.6

Administrative Acetaldehyde 3 0 (0%) <1.9 <1.9

Administrative Acetone 3 3 (100%) ─ ─

Administrative Acetonitrile 3 0 (0%) <1.7 <1.7

Administrative Benzene 3 0 (0%) <1.8 <1.9

Administrative Chloroform 3 0 (0%) <1.8 <1.9

Administrative Ethanol 3 3 (100%) ─ ─

Administrative Ethylbenzene 3 0 (0%) <1.8 <1.9

Administrative Isopropyl Alcohol 3 3 (100%) ─ ─

Administrative Methyl Methacrylate 3 3 (100%) 9.8 11.6

Administrative Methylene Chloride 3 0 (0%) <1.9 <1.9

Administrative Styrene 3 0 (0%) <1.9 <1.9

Administrative Toluene 3 0 (0%) <1.9 <1.9

Administrative alpha-Pinene 3 1 (33%) <=1.7 1.8

Administrative d-Limonene 3 3 (100%) 6.5 11.9

Administrative m,p-Xylene 3 0 (0%) <1.9 <1.9

Administrative n-Hexane 3 3 (100%) ─ ─

Administrative o-Xylene 3 0 (0%) <1.9 <1.9

Exam Room 0 2,3-Butanedione 3 0 (0%) <1.7 <1.8

Exam Room 0 2,3-Hexanedione 3 0 (0%) <1.4 <1.5

Exam Room 0 2,3-Pentanedione 3 0 (0%) <1.5 <1.6

Exam Room 0 Acetaldehyde 3 0 (0%) <1.8 <1.9

Exam Room 0 Acetone 3 3 (100%) ─ ─

Exam Room 0 Acetonitrile 3 0 (0%) <1.6 <1.7

Exam Room 0 Benzene 3 0 (0%) <1.8 <1.9

Exam Room 0 Chloroform 3 0 (0%) <1.8 <1.9

Exam Room 0 Ethanol 3 3 (100%) ─ ─

Exam Room 0 Ethylbenzene 3 0 (0%) <1.8 <1.9

Exam Room 0 Isopropyl Alcohol 3 0 (0%) <1.8 <1.8

Exam Room 0 Methyl Methacrylate 3 3 (100%) 8.2 12.5
C-23

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (PPB) (PPB)

Exam Room 0 Methylene Chloride 3 0 (0%) <1.8 <1.9

Exam Room 0 Styrene 3 0 (0%) <1.8 <1.9

Exam Room 0 Toluene 3 0 (0%) <1.8 <1.9

Exam Room 0 alpha-Pinene 3 2 (67%) <1.7 2.0

Exam Room 0 d-Limonene 3 3 (100%) 5.8 9.7

Exam Room 0 m,p-Xylene 3 0 (0%) <1.8 <1.9

Exam Room 0 n-Hexane 3 3 (100%) ─ ─

Exam Room 0 o-Xylene 3 0 (0%) <1.8 <1.9

Exam Room 1 2,3-Butanedione 3 0 (0%) <1.6 <1.7

Exam Room 1 2,3-Hexanedione 3 0 (0%) <1.4 <1.4

Exam Room 1 2,3-Pentanedione 3 0 (0%) <1.5 <1.5

Exam Room 1 Acetaldehyde 3 0 (0%) <1.8 <1.9

Exam Room 1 Acetone 3 3 (100%) ─ ─

Exam Room 1 Acetonitrile 3 0 (0%) <1.6 <1.7

Exam Room 1 Benzene 3 0 (0%) <1.8 <1.8

Exam Room 1 Chloroform 3 0 (0%) <1.7 <1.8

Exam Room 1 Ethanol 3 3 (100%) ─ ─

Exam Room 1 Ethylbenzene 3 0 (0%) <1.7 <1.8

Exam Room 1 Isopropyl Alcohol 3 3 (100%) ─ ─

Exam Room 1 Methyl Methacrylate 3 3 (100%) 8.8 12.8

Exam Room 1 Methylene Chloride 3 0 (0%) <1.8 <1.9

Exam Room 1 Styrene 3 0 (0%) <1.8 <1.9

Exam Room 1 Toluene 3 0 (0%) <1.8 <1.9

Exam Room 1 alpha-Pinene 3 0 (0%) <1.7 <1.7

Exam Room 1 d-Limonene 3 3 (100%) 5.3 8.3

Exam Room 1 m,p-Xylene 3 0 (0%) <1.8 <1.9

Exam Room 1 n-Hexane 3 3 (100%) ─ ─

Exam Room 1 o-Xylene 3 0 (0%) <1.8 <1.9

Exam Room 2 2,3-Butanedione 3 0 (0%) <1.7 <1.8

Exam Room 2 2,3-Hexanedione 3 0 (0%) <1.5 <1.5

Exam Room 2 2,3-Pentanedione 3 0 (0%) <1.6 <1.6

Exam Room 2 Acetaldehyde 3 0 (0%) <1.9 <1.9

Exam Room 2 Acetone 3 3 (100%) ─ ─

Exam Room 2 Acetonitrile 3 0 (0%) <1.7 <1.7
C-24

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (PPB) (PPB)

Exam Room 2 Benzene 3 0 (0%) <1.9 <1.9

Exam Room 2 Chloroform 3 0 (0%) <1.9 <1.9

Exam Room 2 Ethanol 3 3 (100%) ─ ─

Exam Room 2 Ethylbenzene 3 0 (0%) <1.9 <1.9

Exam Room 2 Isopropyl Alcohol 3 3 (100%) ─ ─

Exam Room 2 Methyl Methacrylate 3 3 (100%) 10.9 11.9

Exam Room 2 Methylene Chloride 3 0 (0%) <1.9 <1.9

Exam Room 2 Styrene 3 0 (0%) <1.9 <1.9

Exam Room 2 Toluene 3 0 (0%) <1.9 <1.9

Exam Room 2 alpha-Pinene 3 2 (67%) <1.8 1.9

Exam Room 2 d-Limonene 3 3 (100%) 7.0 9.4

Exam Room 2 m,p-Xylene 3 0 (0%) <1.9 <1.9

Exam Room 2 n-Hexane 3 3 (100%) ─ ─

Exam Room 2 o-Xylene 3 0 (0%) <1.9 <1.9

Exam Room 3 2,3-Butanedione 3 0 (0%) <1.7 <1.8

Exam Room 3 2,3-Hexanedione 3 0 (0%) <1.4 <1.5

Exam Room 3 2,3-Pentanedione 3 0 (0%) <1.5 <1.7

Exam Room 3 Acetaldehyde 3 0 (0%) <1.8 <2.0

Exam Room 3 Acetone 3 3 (100%) ─ ─

Exam Room 3 Acetonitrile 3 0 (0%) <1.6 <1.8

Exam Room 3 Benzene 3 0 (0%) <1.8 <2.0

Exam Room 3 Chloroform 3 0 (0%) <1.8 <2.0

Exam Room 3 Ethanol 3 3 (100%) ─ ─

Exam Room 3 Ethylbenzene 3 0 (0%) <1.8 <2.0

Exam Room 3 Isopropyl Alcohol 3 3 (100%) ─ ─

Exam Room 3 Methyl Methacrylate 3 3 (100%) 9.9 11.0

Exam Room 3 Methylene Chloride 3 0 (0%) <1.8 <2.0

Exam Room 3 Styrene 3 0 (0%) <1.8 <2.0

Exam Room 3 Toluene 3 0 (0%) <1.8 <2.0

Exam Room 3 alpha-Pinene 3 1 (33%) <1.7 1.9

Exam Room 3 d-Limonene 3 3 (100%) 6.9 9.9

Exam Room 3 m,p-Xylene 3 0 (0%) <1.8 <2.0

Exam Room 3 n-Hexane 3 3 (100%) ─ ─

Exam Room 3 o-Xylene 3 0 (0%) <1.8 <2.0
C-25

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (PPB) (PPB)

Exam Room 4 2,3-Butanedione 3 0 (0%) <1.7 <1.8

Exam Room 4 2,3-Hexanedione 3 0 (0%) <1.4 <1.5

Exam Room 4 2,3-Pentanedione 3 0 (0%) <1.5 <1.6

Exam Room 4 Acetaldehyde 3 0 (0%) <1.8 <1.9

Exam Room 4 Acetone 3 0 (0%) <1.9 <2.0

Exam Room 4 Acetonitrile 3 0 (0%) <1.6 <1.7

Exam Room 4 Benzene 3 0 (0%) <1.8 <1.9

Exam Room 4 Chloroform 3 0 (0%) <1.8 <1.9

Exam Room 4 Ethanol 3 3 (100%) ─ ─

Exam Room 4 Ethylbenzene 3 0 (0%) <1.8 <1.9

Exam Room 4 Isopropyl Alcohol 3 3 (100%) ─ ─

Exam Room 4 Methyl Methacrylate 3 3 (100%) 11.2 12.0

Exam Room 4 Methylene Chloride 3 0 (0%) <1.8 <1.9

Exam Room 4 Styrene 3 0 (0%) <1.8 <1.9

Exam Room 4 Toluene 3 1 (33%) <1.8 3.7

Exam Room 4 alpha-Pinene 3 1 (33%) <1.7 2.1

Exam Room 4 d-Limonene 3 3 (100%) 7.5 10.0

Exam Room 4 m,p-Xylene 3 0 (0%) <1.8 <1.9

Exam Room 4 n-Hexane 3 3 (100%) 0.9 ─

Exam Room 4 o-Xylene 3 0 (0%) <1.8 <1.9

Exam Room 5 2,3-Butanedione 3 0 (0%) <1.7 <1.9

Exam Room 5 2,3-Hexanedione 3 0 (0%) <1.4 <1.6

Exam Room 5 2,3-Pentanedione 3 0 (0%) <1.6 <1.7

Exam Room 5 Acetaldehyde 3 0 (0%) <1.9 <2.0

Exam Room 5 Acetone 3 3 (100%) ─ ─

Exam Room 5 Acetonitrile 3 0 (0%) <1.7 <1.8

Exam Room 5 Benzene 3 0 (0%) <1.9 <2.0

Exam Room 5 Chloroform 3 0 (0%) <1.8 <2.0

Exam Room 5 Ethanol 3 3 (100%) ─ ─

Exam Room 5 Ethylbenzene 3 0 (0%) <1.8 <2.0

Exam Room 5 Isopropyl Alcohol 3 3 (100%) ─ ─

Exam Room 5 Methyl Methacrylate 3 3 (100%) 10.0 10.8

Exam Room 5 Methylene Chloride 3 0 (0%) <1.9 <2.1

Exam Room 5 Styrene 3 0 (0%) <1.9 <2.0
C-26

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (PPB) (PPB)

Exam Room 5 Toluene 3 1 (33%) <1.9 7.1

Exam Room 5 alpha-Pinene 3 0 (0%) <1.7 <1.9

Exam Room 5 d-Limonene 3 3 (100%) 6.8 10.5

Exam Room 5 m,p-Xylene 3 0 (0%) <1.9 <2.1

Exam Room 5 n-Hexane 3 3 (100%) 8.0 ─

Exam Room 5 o-Xylene 3 0 (0%) <1.9 <2.0

Exam Room 6 2,3-Butanedione 3 0 (0%) <1.7 <1.8

Exam Room 6 2,3-Hexanedione 3 0 (0%) <1.4 <1.5

Exam Room 6 2,3-Pentanedione 3 0 (0%) <1.6 <1.6

Exam Room 6 Acetaldehyde 3 0 (0%) <1.9 <2.0

Exam Room 6 Acetone 3 3 (100%) ─ ─

Exam Room 6 Acetonitrile 3 0 (0%) <1.7 <1.8

Exam Room 6 Benzene 3 0 (0%) <1.9 <1.9

Exam Room 6 Chloroform 3 0 (0%) <1.8 <1.9

Exam Room 6 Ethanol 3 3 (100%) ─ ─

Exam Room 6 Ethylbenzene 3 0 (0%) <1.8 <1.9

Exam Room 6 Isopropyl Alcohol 3 3 (100%) ─ ─

Exam Room 6 Methyl Methacrylate 3 3 (100%) 10.4 12.6

Exam Room 6 Methylene Chloride 3 0 (0%) <1.9 <2.0

Exam Room 6 Styrene 3 0 (0%) <1.9 <1.9

Exam Room 6 Toluene 3 0 (0%) <1.9 <2.0

Exam Room 6 alpha-Pinene 3 2 (67%) <=1.8 1.8

Exam Room 6 d-Limonene 3 3 (100%) 6.5 9.9

Exam Room 6 m,p-Xylene 3 0 (0%) <1.9 <2.0

Exam Room 6 n-Hexane 3 3 (100%) 7.5 >7.5

Exam Room 6 o-Xylene 3 0 (0%) <1.9 <1.9

Exam Room 7 2,3-Butanedione 3 0 (0%) <1.8 <1.8

Exam Room 7 2,3-Hexanedione 3 0 (0%) <1.5 <1.5

Exam Room 7 2,3-Pentanedione 3 0 (0%) <1.6 <1.6

Exam Room 7 Acetaldehyde 3 0 (0%) <1.9 <2.0

Exam Room 7 Acetone 3 3 (100%) ─ ─

Exam Room 7 Acetonitrile 3 0 (0%) <1.7 <1.8

Exam Room 7 Benzene 3 0 (0%) <1.9 <1.9

Exam Room 7 Chloroform 3 0 (0%) <1.9 <1.9
C-27

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (PPB) (PPB)

Exam Room 7 Ethanol 3 3 (100%) ─ ─

Exam Room 7 Ethylbenzene 3 0 (0%) <1.9 <1.9

Exam Room 7 Isopropyl Alcohol 3 3 (100%) ─ ─

Exam Room 7 Methyl Methacrylate 3 3 (100%) 10.0 11.8

Exam Room 7 Methylene Chloride 3 0 (0%) <1.9 <2.0

Exam Room 7 Styrene 3 0 (0%) <1.9 <1.9

Exam Room 7 Toluene 3 0 (0%) <1.9 <2.0

Exam Room 7 alpha-Pinene 3 1 (33%) <1.8 1.8

Exam Room 7 d-Limonene 3 3 (100%) 6.7 9.9

Exam Room 7 m,p-Xylene 3 0 (0%) <1.9 <2.0

Exam Room 7 n-Hexane 3 3 (100%) 7.7 ─

Exam Room 7 o-Xylene 3 0 (0%) <1.9 <1.9

Lab Area 2,3-Butanedione 3 0 (0%) <1.7 <1.8

Lab Area 2,3-Hexanedione 3 0 (0%) <1.4 <1.5

Lab Area 2,3-Pentanedione 3 0 (0%) <1.6 <1.6

Lab Area Acetaldehyde 3 0 (0%) <1.9 <2.0

Lab Area Acetone 3 3 (100%) ─ ─

Lab Area Acetonitrile 3 0 (0%) <1.7 <1.8

Lab Area Benzene 3 0 (0%) <1.9 <1.9

Lab Area Chloroform 3 0 (0%) <1.8 <1.9

Lab Area Ethanol 3 3 (100%) ─ ─

Lab Area Ethylbenzene 3 0 (0%) <1.8 <1.9

Lab Area Isopropyl Alcohol 3 3 (100%) ─ ─

Lab Area Methyl Methacrylate 3 3 (100%) 11.4 11.9

Lab Area Methylene Chloride 3 0 (0%) <1.9 <2.0

Lab Area Styrene 3 0 (0%) <1.9 <1.9

Lab Area Toluene 3 0 (0%) <1.9 <2.0

Lab Area alpha-Pinene 3 2 (67%) <1.7 1.9

Lab Area d-Limonene 3 3 (100%) 6.8 10.6

Lab Area m,p-Xylene 3 0 (0%) <1.9 <2.0

Lab Area n-Hexane 3 3 (100%) 7.3 ─

Lab Area o-Xylene 3 0 (0%) <1.9 <1.9

Sterilization 2,3-Butanedione 3 0 (0%) <1.7 <1.8

Sterilization 2,3-Hexanedione 3 0 (0%) <1.4 <1.5
C-28

Above Minimum Maximum 

Work Area Analyte N LOD Concentration Concentration

N (%) (PPB) (PPB)

Sterilization 2,3-Pentanedione 3 0 (0%) <1.6 <1.6

Sterilization Acetaldehyde 3 0 (0%) <1.9 <1.9

Sterilization Acetone 3 3 (100%) ─ ─

Sterilization Acetonitrile 3 0 (0%) <1.7 <1.7

Sterilization Benzene 3 0 (0%) <1.9 <1.9

Sterilization Chloroform 3 0 (0%) <1.8 <1.9

Sterilization Ethanol 3 3 (100%) ─ ─

Sterilization Ethylbenzene 3 0 (0%) <1.8 <1.9

Sterilization Isopropyl Alcohol 3 3 (100%) ─ ─

Sterilization Methyl Methacrylate 3 3 (100%) 9.8 >9.8

Sterilization Methylene Chloride 3 0 (0%) <1.9 <1.9

Sterilization Styrene 3 0 (0%) <1.9 <1.9

Sterilization Toluene 3 0 (0%) <1.9 <1.9

Sterilization alpha-Pinene 3 0 (0%) <1.7 <1.8

Sterilization d-Limonene 3 3 (100%) 6.7 11.7

Sterilization m,p-Xylene 3 0 (0%) <1.9 <1.9

Sterilization n-Hexane 3 3 (100%) 7.4 ─

Sterilization o-Xylene 3 0 (0%) <1.9 <1.9

N=number of samples; LOD=limit of detection; PPB=parts per billion. “─” indicates measurements 

above the calibration maximum.
C-29

Table C6. Instantaneous canister measurements of volatile organic compounds collected in the 

breathing zone of an employee while using aluminum oxide in the enclosed sandblaster in the lab area, 

June 2019.

Minimum Maximum 

Analyte N Above LOD, N (%) Concentration Concentration

(PPB) (PPB)

2,3-Butanedione 2 0 (0%) <0.7 <0.7

2,3-Hexanedione 2 1 (50%) <1.1 1.8

2,3-Pentanedione 2 0 (0%) <0.7 <0.8

Acetaldehyde 2 2 (100%) 17.9 18.3

Acetone 2 2 (100%) 96.7 98.4

Acetonitrile 2 0 (0%) <1.9 <2.0

Benzene 2 1 (50%) <0.4 1.1

Chloroform 2 2 (100%) 1.4 1.5

D-Limonene 2 2 (100%) 5.1 7.3

Ethanol 2 2 (100%) ─ ─

Ethylbenzene 2 0 (0%) <0.4 <0.4

Isopropyl Alcohol 2 2 (100%) ─ ─

Methyl Methacrylate 2 2 (100%) 10.9 12.2

Methylene Chloride 2 1 (50%) <0.1 0.4

Styrene 2 1 (50%) <0.7 1.6

Toluene 2 0 (0%) <0.6 <0.6

alpha-Pinene 2 0 (0%) <0.5 <0.5

m,p-Xylene 2 2 (100%) 1.0 1.0

n-Hexane 2 2 (100%) 1.5 1.5

o-Xylene 2 0 (0%) <0.2 <0.2

N=number of samples; LOD=limit of detection; PPB=parts per billion. “─” indicates measurements 

above the calibration maximum.
C-0

Table C7. Instantaneous canister measurements of sources of volatile organic compounds during specific tasks, June 2019.

Above Minimum Maximum 

Work Area Analyte Source Description N LOD Concentration Concentration

N (%) (PPB) (PPB)

Exam Room 2 2,3-Butanedione Collected above patient’s head during placement of amalgam 1 0 (0%) <0.6 <0.6

Exam Room 2 2,3-Butanedione Collected above patient’s head during removal of amalgam 1 0 (0%) <0.7 <0.7

Exam Room 2 2,3-Butanedione Collected above dentist’s shoulder during removal of 1 0 (0%) <0.8 <0.8

amalgam

Exam Room 2 2,3-Hexanedione Collected above patient’s head during placement of amalgam 1 0 (0%) <0.9 <0.9

Exam Room 2 2,3-Hexanedione Collected above patient’s head during removal of amalgam 1 0 (0%) <1.0 <1.0

Exam Room 2 2,3-Hexanedione Collected above dentist’s shoulder during removal of 1 0 (0%) <1.2 <1.2

amalgam

Exam Room 2 2,3-Pentanedione Collected above patient’s head during placement of amalgam 1 0 (0%) <0.6 <0.6

Exam Room 2 2,3-Pentanedione Collected above patient’s head during removal of amalgam 1 0 (0%) <0.7 <0.7

Exam Room 2 2,3-Pentanedione Collected above dentist’s shoulder during removal of 1 0 (0%) <0.9 <0.9

amalgam

Exam Room 2 Acetaldehyde Collected above patient’s head during placement of amalgam 1 1 (100%) 21.9 21.9

Exam Room 2 Acetaldehyde Collected above patient’s head during removal of amalgam 1 1 (100%) 23.7 23.7

Exam Room 2 Acetaldehyde Collected above dentist’s shoulder during removal of 1 1 (100%) 28.9 28.9

amalgam

Exam Room 2 Acetone Collected above patient’s head during placement of amalgam 1 1 (100%) 156.5 156.5

Exam Room 2 Acetone Collected above patient’s head during removal of amalgam 1 1 (100%) 181.0 181.0

Exam Room 2 Acetone Collected above dentist’s shoulder during removal of 1 1 (100%) 193.8 193.8

amalgam

Exam Room 2 Acetonitrile Collected above patient’s head during placement of amalgam 1 0 (0%) <1.7 <1.7

Exam Room 2 Acetonitrile Collected above patient’s head during removal of amalgam 1 0 (0%) <1.8 <1.8

Exam Room 2 Acetonitrile Collected above dentist’s shoulder during removal of 1 0 (0%) <2.3 <2.3

amalgam
C-1

Above Minimum Maximum 

Work Area Analyte Source Description N LOD Concentration Concentration

N (%) (PPB) (PPB)

Exam Room 2 Benzene Collected above patient’s head during placement of amalgam 1 1 (100%) 1.0 1.0

Exam Room 2 Benzene Collected above patient’s head during removal of amalgam 1 1 (100%) 1.1 1.1

Exam Room 2 Benzene Collected above dentist’s shoulder during removal of 1 1 (100%) 3.0 3.0

amalgam

Exam Room 2 Chloroform Collected above patient’s head during placement of amalgam 1 0 (0%) <0.0 <0.0

Exam Room 2 Chloroform Collected above patient’s head during removal of amalgam 1 1 (100%) 0.9 0.9

Exam Room 2 Chloroform Collected above dentist’s shoulder during removal of 1 0 (0%) <0.0 <0.0

amalgam

Exam Room 2 D-Limonene Collected above patient’s head during placement of amalgam 1 1 (100%) 5.8 5.8

Exam Room 2 D-Limonene Collected above patient’s head during removal of amalgam 1 1 (100%) 7.3 7.3

Exam Room 2 D-Limonene Collected above dentist’s shoulder during removal of 1 1 (100%) 6.9 6.9

amalgam

Exam Room 2 Ethanol Collected above patient’s head during placement of amalgam 1 1 (100%) ─ ─

Exam Room 2 Ethanol Collected above patient’s head during removal of amalgam 1 1 (100%) ─ ─

Exam Room 2 Ethanol Collected above dentist’s shoulder during removal of 1 1 (100%) ─ ─

amalgam

Exam Room 2 Ethylbenzene Collected above patient’s head during placement of amalgam 1 0 (0%) <0.4 <0.4

Exam Room 2 Ethylbenzene Collected above patient’s head during removal of amalgam 1 0 (0%) <0.4 <0.4

Exam Room 2 Ethylbenzene Collected above dentist’s shoulder during removal of 1 0 (0%) <0.5 <0.5

amalgam

Exam Room 2 Isopropyl Alcohol Collected above patient’s head during placement of amalgam 1 1 (100%) ─ ─

Exam Room 2 Isopropyl Alcohol Collected above patient’s head during removal of amalgam 1 1 (100%) ─ ─

Exam Room 2 Isopropyl Alcohol Collected above dentist’s shoulder during removal of 1 1 (100%) ─ ─

amalgam
C-2

Above Minimum Maximum 

Work Area Analyte Source Description N LOD Concentration Concentration

N (%) (PPB) (PPB)

Exam Room 2 Methyl Methacrylate Collected above patient’s head during placement of amalgam 1 1 (100%) 9.4 9.4

Exam Room 2 Methyl Methacrylate Collected above patient’s head during removal of amalgam 1 1 (100%) 10.0 10.0

Exam Room 2 Methyl Methacrylate Collected above dentist’s shoulder during removal of 1 1 (100%) 9.9 9.9

amalgam

Exam Room 2 Methylene Chloride Collected above patient’s head during placement of amalgam 1 1 (100%) 0.4 0.4

Exam Room 2 Methylene Chloride Collected above patient’s head during removal of amalgam 1 0 (0%) <0.1 <0.1

Exam Room 2 Methylene Chloride Collected above dentist’s shoulder during removal of 1 0 (0%) <0.1 <0.1

amalgam

Exam Room 2 Styrene Collected above patient’s head during placement of amalgam 1 0 (0%) <0.6 <0.6

Exam Room 2 Styrene Collected above patient’s head during removal of amalgam 1 1 (100%) 3.4 3.4

Exam Room 2 Styrene Collected above dentist’s shoulder during removal of 1 1 (100%) 1.8 1.8

amalgam

Exam Room 2 Toluene Collected above patient’s head during placement of amalgam 1 1 (100%) 1.8 1.8

Exam Room 2 Toluene Collected above patient’s head during removal of amalgam 1 1 (100%) 0.7 0.7

Exam Room 2 Toluene Collected above dentist’s shoulder during removal of 1 0 (0%) <0.7 <0.7

amalgam

Exam Room 2 alpha-Pinene Collected above patient’s head during placement of amalgam 1 0 (0%) <0.4 <0.4

Exam Room 2 alpha-Pinene Collected above patient’s head during removal of amalgam 1 0 (0%) <0.4 <0.4

Exam Room 2 alpha-Pinene Collected above dentist’s shoulder during removal of 1 0 (0%) <0.5 <0.5

amalgam

Exam Room 2 m,p-Xylene Collected above patient’s head during placement of amalgam 1 1 (100%) 0.9 0.9

Exam Room 2 m,p-Xylene Collected above patient’s head during removal of amalgam 1 1 (100%) 0.9 0.9

Exam Room 2 m,p-Xylene Collected above dentist’s shoulder during removal of 1 1 (100%) 1.1 1.1

amalgam
C-3

Above Minimum Maximum 

Work Area Analyte Source Description N LOD Concentration Concentration

N (%) (PPB) (PPB)

Exam Room 2 n-Hexane Collected above patient’s head during placement of amalgam 1 1 (100%) 26.7 26.7

Exam Room 2 n-Hexane Collected above patient’s head during removal of amalgam 1 1 (100%) 28.6 28.6

Exam Room 2 n-Hexane Collected above dentist’s shoulder during removal of 1 1 (100%) 29.1 29.1

amalgam

Exam Room 2 o-Xylene Collected above patient’s head during placement of amalgam 1 0 (0%) <0.2 <0.2

Exam Room 2 o-Xylene Collected above patient’s head during removal of amalgam 1 0 (0%) <0.2 <0.2

Exam Room 2 o-Xylene Collected above dentist’s shoulder during removal of 1 0 (0%) <0.2 <0.2

amalgam

 N=number of samples; LOD=limit of detection; PPB=parts per billion. “─” indicates measurements above the calibration maximum.
C-4

Table C8. Instantaneous canister measurements of volatile organic compounds by work area, June 2019

Above Minimum Maximum 

Work Area Analyte Area Description N LOD Concentration Concentration

N (%) (PPB) (PPB)

Downstairs 2,3-Butanedione Sample collected in center of the room in old lab area 1 0 (0%) <0.6 <0.6

Downstairs 2,3-Butanedione Sample collected in center of the office downstairs 1 0 (0%) <0.6 <0.6

Downstairs 2,3-Butanedione Sample collected in closet with electrical equipment and 1 0 (0%) <0.6 <0.6

scrubs jacket

Downstairs 2,3-Hexanedione Sample collected in center of the room in old lab area 1 0 (0%) <0.9 <0.9

Downstairs 2,3-Hexanedione Sample collected in center of the office downstairs 1 0 (0%) <0.9 <0.9

Downstairs 2,3-Hexanedione Sample collected in closet with electrical equipment and 1 1 (100%) 1.7 1.7

scrubs jacket

Downstairs 2,3-Pentanedione Sample collected in center of the room in old lab area 1 0 (0%) <0.6 <0.6

Downstairs 2,3-Pentanedione Sample collected in center of the office downstairs 1 0 (0%) <0.6 <0.6

Downstairs 2,3-Pentanedione Sample collected in closet with electrical equipment and 1 0 (0%) <0.6 <0.6

scrubs jacket

Downstairs Acetaldehyde Sample collected in center of the room in old lab area 1 1 (100%) 22.1 22.1

Downstairs Acetaldehyde Sample collected in center of the office downstairs 1 1 (100%) 25.1 25.1

Downstairs Acetaldehyde Sample collected in closet with electrical equipment and 1 1 (100%) 47.9 47.9

scrubs jacket

Downstairs Acetone Sample collected in center of the room in old lab area 1 1 (100%) 97.4 97.4

Downstairs Acetone Sample collected in center of the office downstairs 1 1 (100%) 97.9 97.9

Downstairs Acetone Sample collected in closet with electrical equipment and 1 1 (100%) 88.5 88.5

scrubs jacket

Downstairs Acetonitrile Sample collected in center of the room in old lab area 1 0 (0%) <1.6 <1.6

Downstairs Acetonitrile Sample collected in center of the office downstairs 1 0 (0%) <1.6 <1.6

Downstairs Acetonitrile Sample collected in closet with electrical equipment and 1 0 (0%) <1.6 <1.6

scrubs jacket
C-5

Above Minimum Maximum 

Work Area Analyte Area Description N LOD Concentration Concentration

N (%) (PPB) (PPB)

Downstairs Benzene Sample collected in center of the room in old lab area 1 1 (100%) 1.0 1.0

Downstairs Benzene Sample collected in center of the office downstairs 1 1 (100%) 1.0 1.0

Downstairs Benzene Sample collected in closet with electrical equipment and 1 1 (100%) 0.9 0.9

scrubs jacket

Downstairs Chloroform Sample collected in center of the room in old lab area 1 1 (100%) 0.6 0.6

Downstairs Chloroform Sample collected in center of the office downstairs 1 1 (100%) 0.7 0.7

Downstairs Chloroform Sample collected in closet with electrical equipment and 1 1 (100%) 0.7 0.7

scrubs jacket

Downstairs D-Limonene Sample collected in center of the room in old lab area 1 1 (100%) 33.7 33.7

Downstairs D-Limonene Sample collected in center of the office downstairs 1 1 (100%) 18.9 18.9

Downstairs D-Limonene Sample collected in closet with electrical equipment and 1 1 (100%) 15.7 15.7

scrubs jacket

Downstairs Ethanol Sample collected in center of the room in old lab area 1 1 (100%) ─ ─

Downstairs Ethanol Sample collected in center of the office downstairs 1 1 (100%) ─ ─

Downstairs Ethanol Sample collected in closet with electrical equipment and 1 1 (100%) ─ ─

scrubs jacket

Downstairs Ethylbenzene Sample collected in center of the room in old lab area 1 0 (0%) <0.4 <0.4

Downstairs Ethylbenzene Sample collected in center of the office downstairs 1 0 (0%) <0.4 <0.4

Downstairs Ethylbenzene Sample collected in closet with electrical equipment and 1 0 (0%) <0.4 <0.4

scrubs jacket

Downstairs Isopropyl Alcohol Sample collected in center of the room in old lab area 1 1 (100%) ─ ─

Downstairs Isopropyl Alcohol Sample collected in center of the office downstairs 1 1 (100%) ─ ─

Downstairs Isopropyl Alcohol Sample collected in closet with electrical equipment and 1 1 (100%) ─ ─

scrubs jacket
C-6

Above Minimum Maximum 

Work Area Analyte Area Description N LOD Concentration Concentration

N (%) (PPB) (PPB)

Downstairs Methyl Methacrylate Sample collected in center of the room in old lab area 1 1 (100%) 125.5 125.5

Downstairs Methyl Methacrylate Sample collected in center of the office downstairs 1 1 (100%) 24.8 24.8

Downstairs Methyl Methacrylate Sample collected in closet with electrical equipment and 1 1 (100%) 22.5 22.5

scrubs jacket

Downstairs Methylene Chloride Sample collected in center of the room in old lab area 1 1 (100%) 0.4 0.4

Downstairs Methylene Chloride Sample collected in center of the office downstairs 1 1 (100%) 0.4 0.4

Downstairs Methylene Chloride Sample collected in closet with electrical equipment and 1 1 (100%) 0.5 0.5

scrubs jacket

Downstairs Styrene Sample collected in center of the room in old lab area 1 1 (100%) 1.7 1.7

Downstairs Styrene Sample collected in center of the office downstairs 1 1 (100%) 1.6 1.6

Downstairs Styrene Sample collected in closet with electrical equipment and 1 1 (100%) 1.6 1.6

scrubs jacket

Downstairs Toluene Sample collected in center of the room in old lab area 1 1 (100%) 2.7 2.7

Downstairs Toluene Sample collected in center of the office downstairs 1 1 (100%) 0.9 0.9

Downstairs Toluene Sample collected in closet with electrical equipment and 1 1 (100%) 2.1 2.1

scrubs jacket

Downstairs alpha-Pinene Sample collected in center of the room in old lab area 1 0 (0%) <0.4 <0.4

Downstairs alpha-Pinene Sample collected in center of the office downstairs 1 0 (0%) <0.4 <0.4

Downstairs alpha-Pinene Sample collected in closet with electrical equipment and 1 0 (0%) <0.4 <0.4

scrubs jacket

Downstairs m,p-Xylene Sample collected in center of the room in old lab area 1 1 (100%) 1.0 1.0

Downstairs m,p-Xylene Sample collected in center of the office downstairs 1 1 (100%) 0.9 0.9

Downstairs m,p-Xylene Sample collected in closet with electrical equipment and 1 1 (100%) 1.1 1.1

scrubs jacket

Downstairs n-Hexane Sample collected in center of the room in old lab area 1 1 (100%) 10.9 10.9
C-7

Above Minimum Maximum 

Work Area Analyte Area Description N LOD Concentration Concentration

N (%) (PPB) (PPB)

Downstairs n-Hexane Sample collected in center of the office downstairs 1 1 (100%) 8.5 8.5

Downstairs n-Hexane Sample collected in closet with electrical equipment and 1 1 (100%) 7.8 7.8

scrubs jacket

Downstairs o-Xylene Sample collected in center of the room in old lab area 1 1 (100%) 0.6 0.6

Downstairs o-Xylene Sample collected in center of the office downstairs 1 0 (0%) <0.1 <0.1

Downstairs o-Xylene Sample collected in closet with electrical equipment and 1 1 (100%) 0.7 0.7

scrubs jacket

Exam Room 2 2,3-Butanedione Sample collected in center of exam room at completion of 1 0 (0%) <0.7 <0.7

amalgam replacement

Exam Room 2 2,3-Hexanedione Sample collected in center of exam room at completion of 1 0 (0%) <1.0 <1.0

amalgam replacement

Exam Room 2 2,3-Pentanedione Sample collected in center of exam room at completion of 1 0 (0%) <0.7 <0.7

amalgam replacement

Exam Room 2 Acetaldehyde Sample collected in center of exam room at completion of 1 1 (100%) 26.4 26.4

amalgam replacement

Exam Room 2 Acetone Sample collected in center of exam room at completion of 1 1 (100%) 180.2 180.2

amalgam replacement

Exam Room 2 Acetonitrile Sample collected in center of exam room at completion of 1 0 (0%) <1.9 <1.9

amalgam replacement

Exam Room 2 Benzene Sample collected in center of exam room at completion of 1 1 (100%) 1.1 1.1

amalgam replacement

Exam Room 2 Chloroform Sample collected in center of exam room at completion of 1 0 (0%) <0.0 <0.0

amalgam replacement

Exam Room 2 D-Limonene Sample collected in center of exam room at completion of 1 1 (100%) 6.9 6.9

amalgam replacement
C-8

Above Minimum Maximum 

Work Area Analyte Area Description N LOD Concentration Concentration

N (%) (PPB) (PPB)

Exam Room 2 Ethanol Sample collected in center of exam room at completion of 1 1 (100%) ─ ─

amalgam replacement

Exam Room 2 Ethylbenzene Sample collected in center of exam room at completion of 1 0 (0%) <0.4 <0.4

amalgam replacement

Exam Room 2 Isopropyl Alcohol Sample collected in center of exam room at completion of 1 1 (100%) ─ ─

amalgam replacement

Exam Room 2 Methyl Methacrylate Sample collected in center of exam room at completion of 1 1 (100%) 9.7 9.7

amalgam replacement

Exam Room 2 Methylene Chloride Sample collected in center of exam room at completion of 1 0 (0%) <0.1 <0.1

amalgam replacement

Exam Room 2 Styrene Sample collected in center of exam room at completion of 1 1 (100%) 1.6 1.6

amalgam replacement

Exam Room 2 Toluene Sample collected in center of exam room at completion of 1 0 (0%) <0.6 <0.6

amalgam replacement

Exam Room 2 alpha-Pinene Sample collected in center of exam room at completion of 1 0 (0%) <0.5 <0.5

amalgam replacement

Exam Room 2 m,p-Xylene Sample collected in center of exam room at completion of 1 1 (100%) 1.0 1.0

amalgam replacement

Exam Room 2 n-Hexane Sample collected in center of exam room at completion of 1 1 (100%) 27.3 27.3

amalgam replacement

Exam Room 2 o-Xylene Sample collected in center of exam room at completion of 1 0 (0%) <0.2 <0.2

amalgam replacement

Lab Area 2,3-Butanedione Sample collected in lab area during abrasive procedure 1 1 (100%) 2.3 2.3

with enclosed sandblaster
C-9

Above Minimum Maximum 

Work Area Analyte Area Description N LOD Concentration Concentration

N (%) (PPB) (PPB)

Lab Area 2,3-Hexanedione Sample collected in lab area during abrasive procedure 1 1 (100%) 3.3 3.3

with enclosed sandblaster

Lab Area 2,3-Pentanedione Sample collected in lab area during abrasive procedure 1 0 (0%) <1.2 <1.2

with enclosed sandblaster

Lab Area Acetaldehyde Sample collected in lab area during abrasive procedure 1 0 (0%) <2.3 <2.3

with enclosed sandblaster

Lab Area Acetone Sample collected in lab area during abrasive procedure 1 1 (100%) 276.5 276.5

with enclosed sandblaster

Lab Area Acetonitrile Sample collected in lab area during abrasive procedure 1 0 (0%) <3.0 <3.0

with enclosed sandblaster

Lab Area Benzene Sample collected in lab area during abrasive procedure 1 1 (100%) 1.7 1.7

with enclosed sandblaster

Lab Area Chloroform Sample collected in lab area during abrasive procedure 1 1 (100%) 0.8 0.8

with enclosed sandblaster

Lab Area D-Limonene Sample collected in lab area during abrasive procedure 1 1 (100%) 5.1 5.1

with enclosed sandblaster

Lab Area Ethanol Sample collected in lab area during abrasive procedure 1 1 (100%) ─ ─

with enclosed sandblaster

Lab Area Ethylbenzene Sample collected in lab area during abrasive procedure 1 0 (0%) <0.7 <0.7

with enclosed sandblaster

Lab Area Isopropyl Alcohol Sample collected in lab area during abrasive procedure 1 1 (100%) ─ ─

with enclosed sandblaster

Lab Area Methyl Methacrylate Sample collected in lab area during abrasive procedure 1 1 (100%) 9.9 9.9

with enclosed sandblaster
C-10

Above Minimum Maximum 

Work Area Analyte Area Description N LOD Concentration Concentration

N (%) (PPB) (PPB)

Lab Area Methylene Chloride Sample collected in lab area during abrasive procedure 1 0 (0%) <0.2 <0.2

with enclosed sandblaster

Lab Area Styrene Sample collected in lab area during abrasive procedure 1 0 (0%) <1.0 <1.0

with enclosed sandblaster

Lab Area Toluene Sample collected in lab area during abrasive procedure 1 1 (100%) 2.6 2.6

with enclosed sandblaster

Lab Area alpha-Pinene Sample collected in lab area during abrasive procedure 1 0 (0%) <0.7 <0.7

with enclosed sandblaster

Lab Area m,p-Xylene Sample collected in lab area during abrasive procedure 1 1 (100%) 1.4 1.4

with enclosed sandblaster

Lab Area n-Hexane Sample collected in lab area during abrasive procedure 1 1 (100%) 3.1 3.1

with enclosed sandblaster

Lab Area o-Xylene Sample collected in lab area during abrasive procedure 1 0 (0%) <0.3 <0.3

with enclosed sandblaster

N=number of samples; LOD=limit of detection; PPB=parts per billion. “─” indicates measurements above the calibration maximum.
D-1

Section D: Occupational Exposure Limits

NIOSH investigators refer to mandatory (legally enforceable) and recommended occupational exposure 

limits (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 (TWA) exposure. A TWA refers to the average exposure 

during a normal 8- to 10-hour workday. Some chemical substances and physical agents have 

recommended short-term exposure limits (STEL) or ceiling values. Unless otherwise noted, the STEL is 

a 15-minute TWA 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. 

• OSHA, and agency of the U.S. Department of Labor, publishes permissible exposure limits [29 

CFR 1910 for general industry; 29 CFR 1926 for construction industry; and 29 CFR 1917 for 

maritime industry] called PELs. These limits are enforceable in workplaces covered under the 

Occupational Safety and Health Act of 1970. 

• NIOSH recommended exposure limits (RELs) are recommendations based on a critical review 

of scientific and technical information and the adequacy of methods to identify and control the 

hazard. NIOSH RELs are published in the NIOSH Pocket Guide to Chemical Hazards [NIOSH 

2007]. NIOSH also recommends risk management practices (e.g., engineering controls, safe 

work practices, employee education/training, personal protective equipment, and exposure and 

medical monitoring) to minimize the risk of exposure and adverse health effects.

• Other set of OELs commonly used and cited in the United States include the threshold limit 

values or TLVs, which are recommended by ACGIH. The ACGIH TLVs are developed by 

committee members of this professional organization from a review of the published, peerreviewed literature. TLVs are not consensus standards. They are considered voluntary exposure 
D-2

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

control of health hazards” [ACGIH 2020]. 

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-Stoffdatenbank/index-2.jsp, contains international limits 

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

OSHA (Public Law 91-596) 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. 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.
E-3

Section E: References

Health Effects of Mercury, Ethanol, and Isopropyl Alcohol Exposure

NIOSH [2007]. NIOSH pocket guide to chemical hazards. U.S. Department of Health and Human 

Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for 

Occupational Safety and Health, DHHS (NIOSH) Publication No. 2005-149, 

https://www.cdc.gov/niosh/docs/2005-149/pdfs/2005-149.pdf. 

ATSDR [2014]. Medical management guidelines for mercury. U.S. Department of Health and Human 

Services, Public Health Service, Centers for Disease Control and Prevention, Agency for Toxic 

Substances and Disease Registry, Division of Toxicology and Human Health Sciences. 

https://www.atsdr.cdc.gov/MHMI/mmg46.pdf

Health Effects of Methyl Methacrylate Exposure

Aalto-Korte K, Alanko K, Kuuliala O, Jolanki R [2007]. Methacrylate and acrylate allergy in dental 

personnel. Contact dermatitis, 57(5), 324–330, https://doi.org/10.1111/j.1600-0536.2007.01237.x. 

AOEC [2012]. Exposure code lookup. Association of Occupational and Environmental Clinics, 

http://www.aoecdata.org/ExpCodeLookup.aspx.

Jaakkola MS, Leino T, Tammilehto L, Ylöstalo P, Kuosma E, Alanko, K [2007]. Respiratory effects of 

exposure to methacrylates among dental assistants. Allergy 62(6):648-654,

https://doi.org/10.1111/j.1398-9995.2007.01379.x.

Lindström M, Alanko K, Keskinen H, Kanerva L [2002]. Dentist's occupational asthma, 

rhinoconjunctivitis, and allergic contact dermatitis from methacrylates. Allergy 57(6):543-545. 

https://doi.org/10.1034/j.1398-9995.2002.03199.x.

Lozewicz, S., Davison, A. G., Hopkirk, A., Burge, P. S., Boldy, D. A., Riordan, J. F., McGivern, D. V., 

Platts, B. W., Davies, D., & Newman Taylor, A. J. [1985]. Occupational asthma due to methyl 

methacrylate and cyanoacrylates. Thorax, 40(11), 836–839. https://doi.org/10.1136/thx.40.11.836. 

Prajapati, P., Sethuraman, R., Bector, S., Patel, J. R. [2013]. Contact dermatitis due to methyl 

methacrylate: uncommon and unwanted entity for dentists. BMJ case reports, 2013, bcr-2013-200520. 

https://doi.org/10.1136/bcr-2013-200520

Sánchez-Garcia S, Fernández-Nieto M, Sastre J [2009]. Asthma induced by a thermal printer. N Engl J 

Med 360(22):2375–2376, https://doi.org/10.1056/NEJMc0901008. 
E-4

Venables KM, Chan-Yeung M [1997]. Occupational asthma. Lancet 349(9063):1465-1469, 

https://doi.org/10.1016/S0140-6736(96)07219-4.

Health Effects of Styrene Exposure

AOEC [2012]. Exposure code lookup. Association of Occupational and Environmental Clinics, 

http://www.aoecdata.org/ExpCodeLookup.aspx.

Fernández-Nieto M, Quirce S, Fraj J, del Pozo V, Seoane C, Sastre B, Lahoz C, Sastre J [2006]. Airway 

inflammation in occupational asthma caused by styrene. J Allergy Clin Immunol 117(4):948–950,

https://doi.org/10.1016/j.jaci.2005.12.1350. 

Hayes JP, Lambourn L, Hopkirk JA, Durham SR, Taylor AJ [1991]. Occupational asthma due to 

styrene. Thorax 46(5):396-397, https://doi.org/10.1136/thx.46.5.396.

Moscato G, Biscaldi G, Cottica D, Pugliese F, Candura S, Candura F [1987]. Occupational asthma due 

to styrene: two case reports. J Occup Med 29(12):957-960.

Venables KM, Chan-Yeung M [1997]. Occupational asthma. Lancet 349(9063):1465-1469, 

https://doi.org/10.1016/S0140-6736(96)07219-4.

Work-related Asthma

Tarlo SM [2016]. Update on work-exacerbated asthma. Int J Occup Med Environ Health

29(3):369-374, https://doi.org/10.13075/ijomeh.1896.00676.

Tarlo SM, Lemiere C [2014]. Occupational asthma. N Engl J Med 370:640-649, https://doi. 

org/10.1056/NEJMra1301758. 

OSHA [2014]. OSHA fact sheet: Do you have work-related asthma? A guide for you and

your doctor. Washington, D.C.: U.S. Department of Labor, Occupational Safety and Health

Administration, https://www.osha.gov/Publications/OSHA3707.pdf.

Henneberger PK, Redlich CA, Callahan DB, Harber P, Lemière C, Martin J, Tarlo SM,

Vandenplas O, Torén K; ATS Ad Hoc Committee on Work-Exacerbated Asthma [2011]. An

official American Thoracic Society statement: work-exacerbated asthma. Am J Respir Crit

Care Med 184(3):368–378, https://doi.org/10.1164/rccm.812011ST.

Venables KM, Chan-Yeung M [1997]. Occupational asthma. Lancet 349(9063):1465-1469, 

https://doi.org/10.1016/S0140-6736(96)07219-4.
E-5

Methods 

NIOSH [1994]. Mercury: Method 6009. NIOSH Manual of Analytical Methods (NMAM®) Fourth 

Edition. Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, 

Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, 

DHHS (NIOSH) Publication No. 94-113, https://www.cdc.gov/niosh/docs/2003-154/pdfs/6009.pdf.

NIOSH [1996]. Volatile Organic Compounds (Screening): Method 2549. NIOSH Manual of Analytical 

Methods (NMAM®) Fourth Edition. Cincinnati, OH: U.S. Department of Health and Human Services, 

Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational 

Safety and Health, DHHS (NIOSH) Publication No. 94-113, https://www.cdc.gov/niosh/docs/2003-

154/pdfs/2549.pdf. 

NIOSH [1998]. Particulates not otherwise regulated, respirable: Method 0600. NIOSH Manual of

Analytical Methods (NMAM®) Fourth Edition. Cincinnati, OH: U.S. Department of Health and 

Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute 

for Occupational Safety and Health, DHHS (NIOSH) Publication No. 94-113, 

https://www.cdc.gov/niosh/docs/2003-154/pdfs/0600.pdf. 

NIOSH [2003a]. Silica, Crystalline, by XED (filter redeposition): Method 7500. NIOSH Manual of 

Analytical Methods (NMAM®) Fourth Edition. Cincinnati, OH: U.S. Department of Health and 

Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute 

for Occupational Safety and Health, DHHS (NIOSH) Publication No. 94-113, 

https://www.cdc.gov/niosh/docs/2003-154/pdfs/7500.pdf. 

NIOSH [2003b]. Elements by ICP (Hot Block/HCl/HNO3 Digestion): Method 7303. NIOSH Manual 

of Analytical Methods (NMAM®) Fourth Edition. Cincinnati, OH: U.S. Department of Health and 

Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute 

for Occupational Safety and Health, DHHS (NIOSH) Publication No. 94-113, 

https://www.cdc.gov/niosh/docs/2003-154/pdfs/7303.pdf.

NIOSH [2018]. Volatile organic compounds, C1 to C10, Canister method: Method 3900. Cincinnati, 

OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease 

Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) 

Publication No. 2014-151, https://www.cdc.gov/niosh/nmam/pdf/3900.pdf.

Exposure Assessment Discussion

National Center for Biotechnology Information [2020]. PubChem Compound Summary for CID 7501, 

Styrene. https://pubchem.ncbi.nlm.nih.gov/compound/Styrene.

Warwick, D., Young, M., Palmer, J., Ermel, R [2019]. Mercury vapor volatilization from particulate 

generated from dental amalgam removal with a high-speed dental drill – a significant source of 

exposure. J Occup Med Toxicol 14, 22. https://doi.org/10.1186/s12995-019-0240-2.
E-6

WHO [1998]. Methyl Methacrylate. Geneva: World Health Organization.

Occupational Exposure Limits 

ACGIH [2019]. 2019 TLVs® and BEIs®: threshold limit values for chemical substances and physical 

agents and biological exposure indices. Cincinnati, OH: American Conference of Governmental 

Industrial Hygienists. 

CFR [2019]. Code of Federal Regulations. Washington, DC: U.S. Government Printing Office, Office 

of the Federal Register, https://www.ecfr.gov/cgi-bin/ECFR?page=browse. 

NIOSH [2007]. NIOSH pocket guide to chemical hazards. Cincinnati, OH: U.S. Department of Health 

and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational 

Safety and Health, DHHS (NIOSH) Publication No. 2005-149, https://www.cdc.gov/niosh/npg/. 

OSHA [2020]. Permissible exposure limits – annotated tables. Washington, D.C.: U.S. Department of 

Labor, Occupational Safety and Health Administration, https://www.osha.gov/dsg/annotated-pels/.

Ventilation

ANSI/ASHRAE/ASHE [2017]. Standard 170-2017 Ventilation of health care facilities. Atlanta, GA: 

ASHRAE.
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