Evaluating a Persistent 

Nuisance Odor in an 

Office Building 

– Maryland

Diana M. Ceballos, MS, PhD

Gregory A. Burr, CIH

Health Hazard Evaluation Report

HETA 2011-0004-3128

May 2011

DEPARTMENT OF HEALTH AND HUMAN SERVICES

Centers for Disease Control and Prevention

Workplace

Safety and Health

 National Institute for Occupational 

Safety and Health

This Health Hazard Evaluation (HHE) report and any recommendations made herein are for the specific 

facility evaluated and may not be universally applicable. Any recommendations made are not to be 

considered as final statements of NIOSH policy or of any agency or individual involved. Additional HHE 

reports are available at http://www.cdc.gov/niosh/hhe/
The employer shall post a copy of this report 

for a period of 30 calendar days at or near 

the workplace(s) of affected employees. The 

employer shall take steps to insure that the 

posted determinations are not altered, defaced, 

or covered by other material during such 

period. [37 FR 23640, November 7, 1972, as 

amended at 45 FR 2653, January 14, 1980].
Health Hazard Evaluation Report 2011-0004-3128 Page i

Report Abbreviations................................................................................................ii

Highlights of the NIOSH Health Hazard Evaluation........................iii

Summary .........................................................................................................v

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

Assessment.....................................................................................................1

Results and Discussion...............................................................................3

Conclusions....................................................................................................8

Recommendations.......................................................................................9

References.................................................................................................... 11

Contents

Acknowledgments Acknowledgments and Availability of Report................................ 15
Page ii Health Hazard Evaluation Report 2011-0004-3128

Abbreviations

ASTM American Society for Testing and Materials

CRI Carpet and Rug Institute

CO Carbon monoxide

CO2 Carbon dioxide

DNPH 2,4-Dinitrophenylhydrazine

GC/MS Gas chromatography, mass spectrometry

H2S Hydrogen sulfide

HHE Health hazard evaluation

HPLC/MS High performance liquid chromatography, mass spectrometry

HVAC Heating, ventilating, and air-conditioning

IEQ Indoor environmental quality

MERV Minimum efficiency reporting value

mg Milligrams

mL/min Milliliters per minute

MDC Minimum detectable concentration

MQC Minimum quantifiable concentration

NAICS North American Industry Classification System

NIOSH National Institute for Occupational Safety and Health

OEL Occupational exposure limit

ppm Parts per million

RH Relative humidity

TD Thermal desorption

VOCs Volatile organic compounds
Health Hazard Evaluation Report 2011-0004-3128 Page iii

The National Institute for 

Occupational Safety and 

Health (NIOSH) received 

a technical assistance 

request for a health 

hazard evaluation from 

a federal government 

property manager. The 

request concerned 

nausea; headache; and 

eye, nose, throat, and 

respiratory irritation, 

among employees at 

an office leased by 

the property manager. 

Employees believed that 

a persistent chemical 

odor in the office might 

be responsible for these 

symptoms.

Highlights of the

NIOSH Health

Hazard Evaluation

What NIOSH Did

● We visited the office on December 15–16, 2010.

● We measured temperature, relative humidity (RH), carbon 

dioxide, and carbon monoxide (CO).

● We took air samples for hydrogen sulfide (H2S), formaldehyde, 

and volatile organic compounds (VOCs) in the office. We 

also took air samples for the same substances in two nearby 

businesses for comparison.

● We took one paint sample and two carpet bulk samples from 

the office and analyzed them for VOCs.

● We looked for water damage.

● We checked the heating, ventilating, and air-conditioning 

(HVAC) system in the office.

● We talked with employees about the odor in the office.

● After our visit, we mailed a survey to all office employees asking 

if they noticed any odors at work or had any health concerns.

What NIOSH Found

● The HVAC system did not bring in much outdoor air to the 

occupied office areas.

● The HVAC fan ran only when heating or cooling was needed. 

This can cause stagnant air in the office.

● Odors from the bathrooms and locker rooms could enter the 

office.

● Temperature and RH levels were within suggested guidelines.

● No H2S was detected, and CO concentrations were low in the 

office.

● Although formaldehyde concentrations were low, some 

employees still could have irritation symptoms.

● Six out of eight employees described an odor in the office as 

similar to glue, adhesive, plastic, chemical, or a cleaner.

● One employee reported occasional headaches caused by the 

odor and two reported burning eyes.
Page iv Health Hazard Evaluation Report 2011-0004-3128

● VOCs in air samples collected in the carpeted areas of the office 

matched VOCs from the two bulk carpet samples. These VOCs 

were not found in air samples collected from non-carpeted 

areas in the office or the two nearby businesses that were not 

carpeted.

● The odor is likely caused by VOCs from the carpet adhesive 

and backing.

What Managers Can Do

● Talk with the building owner about removing the carpet and 

adhesive to eliminate the source of odor.

● Prepare the concrete slab floor appropriately before any new 

flooring is installed.

● Set the HVAC fan to run continuously.

● Test the efficiency of the HVAC system outdoor air intake.

● Exhaust the bathrooms and locker rooms to keep odors from 

entering the office.

● Limit the use of air fresheners, room deodorizers, and 

cleaners.

● Record any work-related complaints or problems from 

employees and quickly investigate these issues and record any 

actions taken.

What Employees Can Do

● Tell management if you have concerns about the odor of 

cleaning products used in office or odors from renovation 

projects.

● Avoid using air fresheners and room deodorizers. The odor 

from these can irritate some people. 

Highlights of the

NIOSH Health

Hazard Evaluation

 (continued)
Health Hazard Evaluation Report 2011-0004-3128 Page v

NIOSH was asked to 

evaluate a persistent odor 

in an office. We found 

that air samples from 

the carpeted areas of 

the office had the same 

VOCs that were found in 

bulk samples of carpet 

and carpet adhesive. Eye 

irritation and headaches 

reported by some of the 

employees are consistent 

with exposure to the 

VOCs found in the air. To 

eliminate the odor, we 

recommend removing the 

carpet and adhesive from 

the office.

Summary

NIOSH investigators evaluated a federal government office on 

December 15–16, 2010, after receiving a technical assistance 

request from the property manager. The office employees believed 

a chemical odor present since the building opened in 2007 was 

responsible for their symptoms, which included nausea; headache; 

and eye, nose, throat, and respiratory irritation. We measured 

temperature, RH, CO2, and CO in the office. We took air samples 

for H2S, formaldehyde, and VOCs in the office and in two nearby 

businesses for comparison. We took carpet and paint samples from 

the office and analyzed them for VOCs. We also looked for water 

damage in the office and checked the HVAC system. We surveyed 

employees about odors in the office, asking them to describe the 

odors and health concerns they associated with the odor.

The CO2 concentrations inside the office had a range of 750–1160 

ppm, while the CO2 concentrations outdoors had a range of 

420–440 ppm. Usually, CO2 concentrations are used to determine 

the adequacy of an HVAC system, but not for sparsely occupied 

areas such as this office. However, with only two employees 

working, the fact that indoor CO2 concentrations were nearly triple 

the outdoor concentration indicated the HVAC system was likely 

not introducing much outdoor air into the occupied office areas. 

Temperature in the office had a range of 71–75 °F and RH had a 

range of 21–28%, compared to outdoor temperature, which had 

a range of 18–27 °F and RH at 20%. These levels are within the 

recommended thermal comfort guidelines for the winter season. 

The CO concentrations were low (0–0.1 ppm) and were likely 

caused by the entrance door to the office being located adjacent to 

a parking lot. No water damage in the office was identified.

No H2S was detected (detection limit was 1 ppm) and formaldehyde 

was less than 0.02 ppm in the office and ranged up to 0.03 ppm 

in the adjacent businesses. The formaldehyde concentrations are 

below some exposure guidelines for office spaces (0.05–0.10 ppm) 

but above other recommended indoor air levels for offices (0.003 

ppm). In area air samples collected from carpeted areas of the 

office, we identified VOCs (specifically alcohols) that were similar 

to VOCs from a headspace analysis of carpet taken from the office. 

These VOCs were not found in air samples taken in non-carpeted 

areas of the office or from two nearby businesses that were not 

carpeted. This suggests that either the carpet or incompletely cured 

carpet adhesive may be the source of the odor. Incomplete curing of 

the carpet adhesive can happen when the concrete slab onto which 

the carpet was installed had excessive alkalinity and water vapor.
Page vi Health Hazard Evaluation Report 2010-0004-3128

Keywords: NAICS 926150 (Regulation, Licensing, and Inspection 

of Miscellaneous Commercial Sectors), odor, irritation, office, 

VOCs, indoor environmental quality, IEQ, ventilation, carpet, carpet 

adhesive

We also surveyed employees about odors in the office, asking them 

to describe the odors and any health concerns they associated with 

the odor. All eight office employees returned surveys. Six reported 

having smelled an odor at the office, and four still smelled the 

odor. The odor was described as a glue, adhesive, plastic, chemical, 

or cleaner smell. Two employees mentioned burning of their eyes 

and one mentioned occasional headaches during work, which are 

irritation symptoms typically associated with indoor VOC and 

formaldehyde exposures.

The residential-style electric HVAC system serving the office was 

well maintained and had been modified in 2010 to introduce 

outdoor air. Under some conditions the bathrooms and locker 

rooms were under positive pressure in relationship to the office, 

meaning that odors from the bathrooms and locker rooms could 

enter into the occupied office spaces.

We recommended removing the carpet and adhesive to eliminate 

the source of the odor. We recommended running the HVAC 

system continuously to minimize stagnant air, evaluating the 

HVAC system to determine if enough outdoor air is being 

introduced into the occupied spaces, and to determine if 

bathrooms are under negative pressure. We recommended that 

employees minimize other sources of odor, like air fresheners. We 

also recommended that employees be informed in advance about 

any remediation efforts, such as carpet and adhesive removal and 

the installation of new flooring.

Summary

 (continued)
Page 1

On December 15–16, 2010, we conducted an HHE at a federal 

government office. The HHE was conducted in response to a technical 

assistance request from the property manager for the office and 

concerned reports of eye, nose, throat, and respiratory irritation, as well 

as nausea and headache, among employees at the office leased by the 

property manager. Employees believed that a persistent chemical odor 

in the office might be responsible for their symptoms.

During the visit we met with employer and employee representatives to 

discuss the HHE request. We observed the office layout and workplace 

conditions, and we spoke with employees who were in the office that 

day. We measured temperature, RH, CO2, and CO in the office. We 

also took area air samples for H2S, formaldehyde, and VOCs in the 

office and in two nearby businesses for comparison. We collected two 

bulk samples of carpet from the office and analyzed them for VOC 

emissions. An interim letter, dated January 19, 2011, was sent to the 

property manager and an employee representative. We also sent each 

office employee a survey asking if they smelled an odor while at work 

and if they had health concerns associated with this odor.

Health Hazard Evaluation Report 2010-0004-3128

Introduction

Assessment

The office is in a multitenant two-story commercial building that was 

constructed in 2007. The approximately 3,000-square-foot office is 

on the first floor and contains cubicles separated by fabric-covered 

dividers, one private office, a conference room, an employee break 

room (equipped with a refrigerator, microwave, sink, wall cabinets, 

and small table), and two restrooms. Each restroom has an adjoining 

locker and shower area. One room in the office is used by employees 

to store and calibrate air monitoring equipment (battery-powered air 

sampling pumps, respirable dust cyclone samplers, and combustible 

gas meters) used by employees during mine surveys. No chemicals 

other than liquid detergent (used to clean the Tygon® tubing and 

cyclone samplers) and small (less than 100 liter) cylinders of calibration 

gas were used.

Although eight employees work out of the office, at the time of this 

evaluation only two employees were present the entire day (an office 

assistant and office supervisor). Most employees arrived early to 

calibrate their sampling equipment and then spent the remainder of 

their workday conducting field evaluations outside the office.

During a walkthrough survey of the office we looked for evidence 

of water damage, water incursion, visible mold, and other potential 
Page 2 Health Hazard Evaluation Report 2010-0004-3128

IEQ problems. Spot measurements were taken for CO2, temperature, 

RH, and CO using a Q-TRAKTM Plus Indoor Air Quality Monitor, 

Model 8554 (TSI Incorporated, Shoreview, Minnesota). We collected 

air samples for H2

S, formaldehyde, and VOCs in the office conference 

room, at a work station, and in a non-carpeted information technology 

room. For comparison, we also sampled for H2

S, formaldehyde, 

and VOCs in two nearby businesses where there had been no odor 

complaints. Both businesses had separate HVAC systems and were not 

carpeted. Figure 1 depicts the equipment used in these areas to sample 

for H2

S, formaldehyde, and VOCs.

Area air samples for H2

S were collected using a direct-reading GasAlert 

Extreme meter (BW Technologies America, Arlington, Texas). This 

meter continuously measures H2

S in the range of 0–100 ppm. 

Formaldehyde area air samples were collected using DNPH tubes (Part 

No. 226-120, SKC Inc., Eighty Four, Pennsylvania) at a nominal flow 

rate of 200 mL/min. The samples were analyzed using HPLC/MS 

detection according to NIOSH Method 2016 with an MDC of 0.005 

ppm and MQC of 0.0011 ppm [NIOSH 2011].

Area air samples for VOCs were collected using TD tubes and charcoal 

tubes. The TD tubes, each containing three beds of sorbent material 

(90 mg Carbopack Y, 115 mg Carbopack B, and 150 mg Carboxen 

1003), were collected at a nominal flow rate of 50 mL/min and then 

qualitatively analyzed by NIOSH Method 2549 using GC/MS detection 

[NIOSH 2011]. Side-by-side charcoal tube samples were collected at 

a nominal flow rate of 200 mL/min. We quantitatively analyze the 

charcoal tube samples only if the qualitative TD tube results suggest 

specific air contaminants are present in concentrations sufficient for 

quantitative analysis. Because this was not the case in this evaluation, 

the charcoal tubes were not analyzed.

We collected one paint sample and two carpet bulk samples from the 

office to determine if the carpet or paint may have been the source of 

the persistent odor. One carpet sample taken from beneath a filing 

cabinet had adhesive residue that was still tacky to the touch (Figure 

2). The other carpet sample, taken from a more exposed area in the 

office conference room, had no tacky adhesive residue. The paint 

sample was taken from the conference room wall. Each bulk sample 

was placed in a separate sealable plastic bag for transport. The bulk 

samples were analyzed in the NIOSH laboratory by inserting a TD tube 

into the plastic bag to sample the air at room temperature (a technique 

commonly described as a headspace analysis). An air sample was also 

collected from a clean, unused plastic bag to correct for any background 

Assessment

 (continued)

Figure 1. The air sampler inlets 

were positioned 5 feet above the 

floor to measure hydrogen sulfide, 

formaldehyde, and VOCs.

Figure 2. NIOSH investigator collecting 

a bulk carpet sample.
Health Hazard Evaluation Report 2010-0004-3128 Page 3

Assessment

 (continued) chemicals that may be present. Headspace samples were collected at a 

nominal flow rate of 100 mL/min and analyzed per NIOSH Method 

2549 [NIOSH 2011]. In addition, a small portion of the tacky carpet 

adhesive from the bulk carpet sample was placed in a quartz TD tube, 

secured at both ends with glass wool, heated to 50 °C for 10 minutes in 

the TD unit, and analyzed by GC/MS.

We used ventilation smoke tubes to evaluate air patterns in the office 

and restrooms. We examined the residential style (demand mode) 

HVAC system, including the type of air filters used and the outdoor air 

intakes installed by the building’s owner in 2010.

Because we only had the opportunity to speak with three office 

employees during our site visit, we mailed an IEQ survey form to each 

office employee. This form confidentially asked the employees about 

their work history, how frequently they were in the office, whether they 

had ever smelled an odor while at work, and if they have had any workrelated health concerns or discomfort.

Results and Discussion

IEQ Comfort Indicators

The CO2 concentrations in the office had a range of 750–1160 ppm; 

outdoor concentrations had a range of 420–440 ppm. We compare 

indoor and outdoor CO2 concentrations to determine if indoor 

occupied spaces are adequately ventilated [ANSI/ASHRAE 2010a]. 

Because the office was sparsely occupied during our evaluation, 

comparing CO2 concentrations is not a good indicator of the 

adequacy of the ventilation system. However, considering that with 

only two employees working, indoor CO2 concentrations were 

nearly triple the outdoor concentration, the HVAC system was not 

introducing much outdoor air into the occupied office areas.

Temperature in the office had a range of 71–75 °F and RH had 

a range of 21–28%, compared to an outdoor temperature, which 

had a range of 18–27 °F and RH of approximately 20%. These 

temperature and RH values are within the American Society 

of Heating, Refrigerating, and Air Conditioning Engineers 

recommended thermal comfort guidelines for the winter season 

[ANSI/ASHRAE 2010b].
Page 4 Health Hazard Evaluation Report 2010-0004-3128

Hydrogen Sulfide, Formaldehyde, and 

Carbon Monoxide

No H2S was detected; the limit of detection was 1 ppm. Formaldehyde 

concentrations inside the office remained consistent over the 2 days 

of this evaluation at 0.02 ppm, while the concentration outside the 

office was estimated at 0.00019 ppm (between the MDC and MQC). 

The indoor formaldehyde concentrations in the two nearby businesses 

had a range of 0.02–0.03 ppm. These formaldehyde concentrations 

were below a recommended exposure guideline of 0.10 ppm for 

office spaces, which has been adopted by several organizations [EPA 

1991; NIOSH 1991]. Although this guideline is intended to provide 

reasonable protection against irritation (e.g., irritation of the eyes, 

nose, or throat) in the normal population, hypersensitivity reactions 

may occur at lower levels of exposure. A NIOSH researcher has 

recommended that a 0.05 ppm concentration of formaldehyde be 

used as a pre-occupancy guideline for NIOSH facilities [Wallingford 

2009]. This recommendation is based in part on IEQ specifications 

developed for new office buildings by the State of Washington [State 

of Washington 1989]. A more conservative recommended indoor air 

level for formaldehyde (0.003 ppm) was suggested by Salonen et al. 

[2009]. Because formaldehyde concentrations inside the office were 

above 0.003 ppm, it is possible that some of the irritation symptoms in 

the office could be associated with indoor formaldehyde emissions. The 

CO concentrations were very low (0–0.1 ppm) and were likely due to 

vehicular traffic in the parking lot immediately adjacent to the office.

Volatile Organic Compounds

A pattern of VOCs identified as aliphatic oxy-compounds (possibly 

alcohols) were detected in area air TD samples collected from the 

carpeted areas of the office where the odor was reported by employees. 

These compounds eluted between n-octanol and n-decanol. The same 

VOC pattern was identified in headspace analyses of bulk carpet 

samples but not from the headspace of the bulk paint sample taken 

from the office. Further, the same VOC pattern identified in carpeted 

areas was not identified in the air samples taken in non-carpeted areas 

of the office or from two nearby businesses that were not carpeted. 

The bulk carpet sample obtained from beneath a filing cabinet in the 

office had a more distinct odor compared to the other carpet sample 

that was collected in a conference room, presumably because it had 

less opportunity to off-gas as compared to the more exposed carpeting. 

Some of the sticky adhesive from the back of the less exposed carpet 

Results and Discussion

 (continued)
Health Hazard Evaluation Report 2010-0004-3128 Page 5

sample was removed for headspace analysis. These same aliphatic oxycompounds were the only ones detected in this sample, suggesting that 

the odor may be from the carpet adhesive and not the carpet backing. 

Figure 3 shows the GC/MS chromatographs from the analysis of air 

taken from carpeted and non-carpeted areas as well as the headspace 

analysis of carpet adhesive. 

The presence of aliphatic oxy-compounds in air samples collected in 

the carpeted areas of the office along with the headspace analyses from 

the bulk samples of carpet and adhesive suggest that the incompletely 

cured carpet adhesive is the likely source of the odor in the office. 

However, we cannot conclusively exclude the carpet backing as an odor 

Results and Discussion

 (continued)

Figure 3. GC/MS chromatographs comparing air samples from carpeted and non-carpeted areas to the results 

from a headspace analysis of carpet adhesive.
Page 6 Health Hazard Evaluation Report 2011-0004-3128

contributor. Excessive alkalinity and water vapor from the concrete 

slab onto which the carpet was directly installed are known to cause 

hydrolysis of carpet backing and adhesive [Offermann et al. 2000]. 

Previous NIOSH investigations of odor complaints where carpet was 

installed over a concrete slab found similar VOCs [Wallingford 2002; 

Sylvain 2009]. Other researchers have suggested the odor may originate 

from the hydrolysis or other degradation of carpet square backing 

components, including incomplete curing of carpet adhesive due to the 

impermeable backing of carpet squares or hydrolysis of carpet adhesive 

by the moisture in the concrete slab beneath the carpet [McLaughlin 

and Aigner 1990]. The CRI has published guidelines specifying suitable 

environmental conditions, floor preparation, and testing of concrete 

subfloors prior to adhesive installations, and these guidelines may be 

used to address odor problems caused by incompletely cured carpet 

adhesive or hydrolysis of plasticizers from the carpet backing [CRI 2011].

VOCs are a large class of organic chemicals (i.e., containing carbon) that 

have a sufficiently high vapor pressure to allow some of the compounds 

to exist in the gaseous state at room temperature. It is widely recognized 

that airborne concentrations of many VOCs in office buildings are 

higher than concentrations in outdoor air because of numerous indoor 

sources of VOCs, and because the relatively low rates of outdoor 

air ventilation typically used in offices prevent the rapid dispersal of 

airborne contaminants [Daisey et al. 1994; Tucker 2000]. The many 

consumer products used in offices (such as cleaners, air fresheners, and 

insect repellents) contain and emit numerous VOCs as well as materials 

and products used in new construction, remodeling, and redecorating 

[Hodgson and Levin 2003].

IEQ studies have measured widely ranging VOC concentrations 

in indoor air, as well as differences in the mixtures of compounds 

present. However, concentrations are usually much lower than any 

occupational exposure standards, except in rare cases with unusual 

sources. A measurement of total VOCs has been used in some studies 

attempting to predict certain types of health effects, but results have 

been inconsistent [Molhave 1991; Levin 1998]. Currently no guideline 

or standard exists for VOCs in nonindustrial workplaces such as the 

office. The European community has revised the concept of total 

VOC measurement to include the identification and quantification of 

67 specific chemicals [Levin 1998]. This is outlined in a report by the 

Nordic Committee on Building Regulations, which recommends 26 

chemical guidelines and presents toxicologically based methodology 

for preparing more [Neilson et al. 1996]. Although important to IEQ 

research, these guidelines are still two-to-three orders of magnitude 

Results and Discussion

 (continued)
Health Hazard Evaluation Report 2011-0004-3128 Page 7

Results and Discussion

 (continued) higher than typical indoor VOC concentrations [Brown et al. 1994; 

Levin 1998].

Although office buildings were extensively studied in the 1980s and 

1990s, few U.S. studies have been published since 2000 [Jia et al. 2010]. 

In the 1990s, VOC studies in offices were conducted in 12 buildings 

in northern California [Daisey et al. 1994]; 70 telecommunications 

offices, data centers and administrative offices across the United States 

[Shields et al. 1996]; and 100 representative office buildings nationwide 

[Apte and Daisey 1999; Girman et al. 1999; Brightman and Moss 2000]. 

Apte and Daisey [1999] reported that carpets are a common indoor 

source of VOCs. Upper respiratory and mucous membrane irritation 

(including the eyes, nose, and throat) and headache are the most 

frequently reported symptoms in office buildings with VOC exposures 

[Apte and Daisey 1999]. Hodgson and Levin [2003] reviewed indoor 

VOC concentrations measured in large office buildings in North 

America since 1990. Even though VOC concentrations in small offices 

generally have not been characterized, the review included large office 

buildings. A new methodology that classifies the relative importance 

of VOCs commonly present in indoor air with respect to their odor 

and sensory irritation potency and noncancer chronic toxicity was 

developed [Hodgson and Levin 2003]. Alcohols are one of the groups 

studied by Hodgson and Levin [2011] because these compounds have 

low odor thresholds. Interestingly, 1-octanol was an alcohol of interest 

because of its low odor threshold (0.7 parts per billion) and nasal 

pungency threshold (310 parts per billion); however, no OEL was 

deduced because 1-octanol has low toxicity [Hodgson and Levin 2011]. 

Odors in buildings caused by VOCs may not be of toxicological concern 

[Hogdson and Levin 2011]. Symptom prevalence is often decreased with 

increasing the per person ventilation rate [Seppänen et al. 1999].

Employee Surveys

All eight office employees completed surveys. Their tenure averaged 

2.4 years (range of 0.8–3.5 years), and they averaged 4 days a week in 

the office (range of 2–5 days), working an average of 4.2 hours per day 

(range of 1.5–9 hours per day). Six employees reported having smelled 

an odor at the office, and four of them could still smell the odor. 

Employees described the odor as “like a glue or plastic,” “cleaner or 

adhesive,” “carpet glue smell,” “chemical smell,” and “plastic.” Two 

employees associated burning of their eyes with the odor, while another 

employee reported occasional headaches. One employee reported 

symptoms that began in May 2008 and improved after the employee 

left the office. This person added that the smell was not as strong, and 
Page 8 Health Hazard Evaluation Report 2011-0004-3128

the health concerns were not an issue any more. No employees reported 

having any other health concerns related to their work at the office.

Ventilation

The HVAC system in the office was an all electric, residential style 

(demand mode) system installed in 2007 when the building was 

completed. The HVAC system was well maintained, and the 1-inch 

thick pleated air filters (MERV 8) were in good condition and correctly 

installed. In 2010, the building owner connected the HVAC system to 

a duct that goes to an outside wall to introduce more outdoor air into 

the office and in turn alleviate the persistent odor. Other than from this 

modification, no outdoor air is introduced into the recirculating HVAC 

system beyond air that may leak in around the doors and windows. We 

did not observe any water damage in the office.

Using ventilation smoke tubes, we determined that the bathrooms and 

locker rooms did not remain under negative pressure in relationship 

to the office if (1) the exhaust ventilation fans in the bathroom/locker 

areas were not operating (note: the bathroom/locker room exhaust fan 

and lights were jointly controlled by a wall switch), or (2) the HVAC 

system fan for the office was operating (regardless of whether the 

bathroom exhaust fans were operating). This means that in either of 

these two situations, nuisance odors from the bathrooms and locker 

rooms could migrate into the office.

Results and Discussion

 (continued)

Conclusions

The persistent chemical odor in the office is likely associated with 

airborne VOCs, specifically aliphatic oxy-compounds (possibly alcohols), 

released from the carpet adhesive and/or the carpet backing. We 

reached this conclusion considering that these VOCs were found in air 

samples collected from carpeted areas of the office (the area with the 

persistent odor) and from headspace analyses obtained from two bulk 

carpet samples from the office. These same VOCs were not detected in 

air samples collected from two nearby businesses that were not carpeted 

and did not have any odor complaints.

Although these VOC exposures were not quantified, we estimate that 

they were below recommended occupational exposure levels because 

of the low response obtained from the TD technique used to identify 

them. VOCs even at low concentrations can be a nuisance odor to 

some individuals. Low levels of formaldehyde were also found in the 

office and in the two adjacent businesses and may be contributing to 

office employees’ irritation symptoms. Eye, nose, throat, and respiratory 
Health Hazard Evaluation Report 2011-0004-3128 Page 9

Based on our findings, we recommend the actions listed below to 

create a more healthful workplace. We encourage the office to use a 

labor-management health and safety committee or working group to 

discuss the recommendations in this report and develop an action 

plan. Those involved in the work can best set priorities and assess the 

feasibility of our recommendations for the specific situation at the 

office. Our recommendations are based on the hierarchy of controls 

approach. This approach groups actions by their likely effectiveness in 

reducing or removing hazards. In most cases, the preferred approach is 

to eliminate hazardous materials or processes and install engineering 

controls to reduce exposure or shield employees. Until such controls 

are in place, or if they are not effective or feasible, administrative 

measures may be needed.

Elimination and Substitution

Elimination or substitution of a toxic/hazardous process material is a 

highly effective means for reducing hazards. Incorporating this strategy 

into the design or development phase of a project, commonly referred 

to as “prevention through design,” is most effective because it reduces 

the need for additional controls in the future. To eliminate the source 

of the odor, we recommend the following:

1. Remove the carpet and adhesive using a method that will not void 

the warranty for the replacement carpet or other floor covering. In 

particular, note that the CRI Carpet Installation Standard does not 

recommend the use of liquid adhesive removers on a concrete slab that 

will receive a new floor covering installed with adhesive [CRI 2011].

2. Hire a qualified independent company to test the concrete slab 

for alkalinity and moisture vapor emissions. The CRI Standard 

recommends that, as a minimum, testing companies should 

demonstrate verifiable experience in concrete moisture testing or 

be certified by a recognized organization [CRI 2011]. Testing must 

conform to ASTM Standards F-1869-04 and F-710-08 [ASTM 

2004, 2008]. Written test results must be provided to the flooring 

contractor [CRI 2011].

Recommendations

irritation, as well as nausea and headache are consistent with irritation 

due to VOC and formaldehyde exposure. However, these symptoms are 

also common to the general population and cannot be directly linked to 

specific work exposures.

Conclusions

 (continued)
Page 10 Health Hazard Evaluation Report 2011-0004-3128

Recommendations

 (continued) 3. Check the bare concrete slab for any noticeable odor. Individuals 

who reported health problems in the office should be offered the 

opportunity to check for odors prior to installing new flooring. If an 

odor is present, determine if concrete needs to be sealed.

4. If new carpeting is installed, wait until the cleaned concrete is dry, 

odor-free, and prepared according to the CRI Standard [CRI 2011]. 

We recommend following the carpet manufacturer’s instructions. 

Manufacturers of low-emitting carpet squares are available at http://

www.greenguard.org.

5. Many IEQ complaints occur in buildings undergoing renovation. 

The following NIOSH website describes the steps necessary to ensure 

acceptable IEQ during building renovation: http://www.cdc.gov/

niosh/topics/indoorenv/ConstructionIEQ.html.

6. Minimize the use of air fresheners or room deodorizers, which could 

cause irritation to some sensitive individuals.

Engineering Controls

Engineering controls reduce exposures to employees by removing the 

hazard from the process or placing a barrier between the hazard and 

the employee. Engineering controls are very effective at protecting 

employees without placing primary responsibility of implementation on 

the employee. 

1. Set the HVAC fan to run continuously.

2. Evaluate the ventilation in the bathrooms and locker rooms to 

make sure that these areas are maintained under negative pressure 

when the office is occupied. Refer to bathroom ventilation 

recommendations from ANSI/ASHRAE [2010a].

3. Evaluate the HVAC system to determine if the outdoor air intakes 

installed in 2010 are effective. Refer to recommendations regarding 

outdoor air intakes by ANSI/ASHRAE [2010a] and Mendell et al. 

[2006]. A qualified ventilation engineer should be consulted.

Administrative Controls

Administrative controls are management-dictated work practices and 

policies to reduce or prevent exposures to workplace hazards. The 

effectiveness of administrative changes in work practices for controlling 

workplace hazards is dependent on management commitment 

and employee acceptance. Regular monitoring and reinforcement 

is necessary to ensure that control policies and procedures are not 

circumvented in the name of convenience or production.
Health Hazard Evaluation Report 2011-0004-3128 Page 11

1. If carpet is replaced, inform office employees about the carpet 

removal and reinstallation project. Information on carpet removal, 

the concrete slab, the characteristics of the replacement carpet or 

flooring systems, and what to expect when the office is re-occupied 

should be provided to employees in a clear and timely manner.

2. Follow-up with employees to ensure that the remedial action has been 

effective.

3. Track and promptly investigate work-related complaints or problems 

reported by employees.

Recommendations

 (continued)

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Page 14 Health Hazard Evaluation Report 2010-0004-3128
Health Hazard Evaluation Report 2011-0004-3128 Page 15

The Hazard Evaluations and Technical Assistance Branch 

(HETAB) of the National Institute for Occupational Safety and 

Health (NIOSH) conducts field investigations of possible health 

hazards in the workplace. These investigations are conducted 

under the authority of Section 20(a)(6) of the Occupational Safety 

and Health Act of 1970, 29 U.S.C. 669(a)(6) which authorizes 

the Secretary of Health and Human Services, following a written 

request from any employer or authorized representative of 

employees, to determine whether any substance normally found 

in the place of employment has potentially toxic effects in such 

concentrations as used or found. HETAB also provides, upon 

request, technical and consultative assistance to federal, state, and 

local agencies; labor; industry; and other groups or individuals to 

control occupational health hazards and to prevent related trauma 

and disease.

The findings and conclusions in this report are those of the 

authors and do not necessarily represent the views of NIOSH. 

Mention of any company or product does not constitute 

endorsement by NIOSH. In addition, citations to websites 

external to NIOSH do not constitute NIOSH endorsement of 

the sponsoring organizations or their programs or products. 

Furthermore, NIOSH is not responsible for the content of these 

websites. All Web addresses referenced in this document were 

accessible as of the publication date.

This report was prepared by Diana M. Ceballos and Gregory A. 

Burr of HETAB, Division of Surveillance, Hazard Evaluations 

and Field Studies. Analytical support was provided by Ardith 

Grote and Jen Roberts of the Division of Applied Research 

and Technology and by Bureau Veritas North America. Health 

communication assistance was provided by Stefanie Evans. 

Editorial assistance was provided by John Lechliter. Desktop 

publishing was performed by Greg Hartle.

Copies of this report have been sent to employee and 

management representatives at the office, the manager, the state 

health department, and the Occupational Safety and Health 

Administration Regional office. This report is not copyrighted and 

may be freely reproduced. The report may be viewed and printed 

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National Technical Information Service at 5825 Port Royal Road, 

Springfield, Virginia 22161.

Acknowledgments and

Availability of Report
Below is a recommended citation for this report:

NIOSH [2011]. Health hazard evaluation report: evaluating a persistent nuisance 

odor in an office building – Maryland. By Ceballos D, Burr G. Cincinnati, OH: U.S. 

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

Prevention, National Institute for Occupational Safety and Health, NIOSH HETA 

No. 2011-0004-3128.

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