Health Hazard Evaluation Report 2015-0050-3308 Page 1

Evaluation of Exposure to Metals, Flame 

Retardants, and Nanomaterials at an Electronics 

Recycling Company

HHE Report No. 2015-0050-3308

May 2018

Catherine C. Beaucham, MPH, CIH

Diana Ceballos, PhD, CIH

Elena H. Page, MD, MPH

Charles Mueller, MS

Antonia M. Calafat, PhD

Andreas Sjodin, PhD

Maria Ospina, PhD

Mark La Guardia, MS

Eric Glassford, MS, CIH
Page 2 Health Hazard Evaluation Report 2015-0050-3308

Contents

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

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

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

Methods ............................................... 4

Results ................................................ 10

Discussion .......................................... 28

Conclusions........................................ 39

Recommendations............................. 40

Appendix A ........................................ 43

Appendix B ........................................ 49

Appendix C ........................................ 50

Appendix D ........................................ 61

References.......................................... 62

Acknowledgements........................... 73

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

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

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

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

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

not be related to this Health Hazard Evaluation. Photo by NIOSH.
Health Hazard Evaluation Report 2015-0050-3308 Page i

We assessed employees’ 

exposures to metals and flame 

retardants at an electronics 

recycling company. We found 

some flame retardants typically 

associated with electronics in 

the air, on employees’ hands, 

in their blood, and in their 

urine (metabolites). We found 

metals in the air and on surfaces 

outside of the processing area. 

One employee’s exposure to 

cadmium in the air was above 

the recommended exposure 

limit. Three employees had 

elevated blood lead levels. We 

recommended adding local 

exhaust ventilation to the small 

shredder sorter, requiring that 

employees in the disassembly 

and shredding areas wear 

respirators until cadmium 

exposures are reduced, and 

supplying outdoor air to the 

office ventilation system. 

Highlights of this Evaluation

The Health Hazard Evaluation Program received a request from an electronics recycling 

company. The employer was concerned about exposure to metals and flame retardant chemical 

compounds occurring during the work process, and whether they were present in the workers’ 

bodies and work environment. We visited the company in March and August 2015.

What We Did

● We observed work practices and spoke informally 

with employees about their work activities. 

● We collected surface, hand wipe, and air 

samples for 30 metals and 24 flame retardants.

● We collected blood samples for cadmium, 

indium, lead, and some polybrominated 

diphenyl ether flame retardants.

● We collected urine samples for some 

organobromine and organophosphorous 

flame retardants.

● We used direct-reading instruments to measure 

the air for mercury and particulate matter.

What We Found

● We found 13 different flame retardants and 19 

different metals in the air samples.

● We observed employees dry sweeping and 

eating and/or drinking in the processing areas.

● One employee in the batteries and disassembly 

area was overexposed to cadmium.

● We found some metals on surfaces outside of the 

processing area.

● Levels of some flame retardants from employee’s 

hands were higher after the work shift than before the work shift. Increases in the 

levels of flame retardants during the work shift, particularly those commonly used on 

electronics, show the potential for dermal exposure. The increases also highlight the 

importance of personal protective equipment and hand washing to reduce exposures.

● We found some flame retardants in employees’ blood and urine. We are not able to 

predict specific health effects from this because the science is not sufficient to do so at 

this time; however, we believe these flame retardants are potentially hazardous. 
Page ii Health Hazard Evaluation Report 2015-0050-3308

● We also found metals in the employees’ blood and urine. These metals can damage the 

body over time. 

● Three employees working in the shredder/sorter area had elevated blood lead levels. 

Lead can cause damage to the body over time.

What the Employer Can Do

● Hire a qualified engineer to evaluate the office ventilation to make sure that sufficient 

air is introduced from the outside, and that air from the warehouse is not mixed with 

the office air.

● Include all processing employees in a lead exposure prevention program.

● Provide employees with a lead-removing product to wash their hands. Soap and water 

is not enough.

● Require employees in the disassembly and shredding areas to wear respirators until 

cadmium exposures are reduced below occupational exposure limits. 

● Provide onsite laundering facilities or contract with a laundering service for all 

employees exposed to lead or cadmium.

What Employees Can Do 

● Wash your hands with a lead-removing product before eating, drinking, smoking, or 

leaving work.

● Do not dry sweep. Use wet cleaning methods or vacuuming instead.

● Use respirators in the disassembly and shredding areas until controls are put in place 

and exposures are reduced below applicable exposure limits.
Health Hazard Evaluation Report 2015-0050-3308 Page iii

Abbreviations

α-HBCD α-hexabromocyclododecane 

β-HBCD β-hexabromocyclododecane

γ-HBCD γ-hexabromocyclododecane

μg/100 cm2 Micrograms per 100 square centimeters

μg/g Micrograms per gram

μg/m3 Micrograms per cubic meter

μg/dL Micrograms per deciliter

μg/L Micrograms per liter

μm Micrometer

ACGIH® American Conference of Governmental Industrial Hygienists

BCEP bis(2-chloroethyl) phosphate

BCIPP bis(l-chloro-2-propyl) phosphate

BDCIPP bis(l,3-dichloro-2-propyl) phosphate

BDE-17 2,2’,4’-tribromodiphenyl ether

BDE-28 2,4,4’-tribromodiphenyl ether

BDE-47 2,2’,4,4’-tetrabromodiphenyl ether

BDE-66 2,3’,4,4’-tetrabromodiphenyl ether

BDE-85 2,2’,3,4,4’-pentabromodiphenyl ether

BDE-99 2,2’,4,4’,5-pentabromodiphenyl ether

BDE-100 2,2’,4,4’,6-pentabromodiphenyl ether

BDE-153 2,2’,4,4’,5,5’-hexabromodiphenyl ether

BDE-154 2,2’,4,4’,5,6’-hexabromodiphenyl ether

BDE-183 2,2’,3,4,4’,5’,6-heptabromodiphenyl ether

BDE-206 2,2’,3,3’,4,4’,5,5’,6-nonabromodiphenyl ether

BDE-209 decabromodiphenyl ether

BEH-TEBP Bis(2-ethylhexyl) tetrabromophthalate

BLL Blood lead levels

BTBPE 1,2-Bis(2,4,6-tribromophenoxy)ethane 

CAS Chemical abstract service

CFR Code of Federal Regulations

DecaBDE Decabromodiphenyl ether technical mixture 

DBDPE Decabromodiphenyl ethane 

DoCP Di-o-cresylphosphate

DpCP Di-pcresylphosphate

DPHP Diphenyl phosphate

EH-TBB 2-ethylhexyl 2,3,4,5-tetrabromobenzoate 
Page iv Health Hazard Evaluation Report 2015-0050-3308

GM Geometric mean

LCD Liquid crystal display

LOD Limit of detection

MDC Minimum detectable concentration

mg/m3 Milligrams per cubic meter

mm Millimeter

mL Milliliter

MOUDI Micro-orifice, uniform deposit impactor

ng/m3 Nanograms per cubic meter 

ng/g Nanograms per gram

ng/sample Nanograms per sample

ND Not detected

nm Nanometer

NHANES National Health and Nutrition Examination Survey

NIOSH National Institute for Occupational Safety and Health

OctaBDE Octabromodiphenyl ether technical mixture 

OEL Occupational exposure limit

OSHA Occupational Safety and Health Administration

PCB Polychlorinated biphenyls

p/cc Particles per cubic centimeter

PBDE Polybrominated diphenyl ethers

PEL Permissible exposure limit

PentaBDE Pentabromodiphenyl ether technical mixture 

PP Persistent pesticides

PPE Personal protective equipment

REL Recommended exposure limit

STEL Short-term exposure limit

TBBA 2,3,4,5-tetrabromobenzoic acid

TBBPA Tetrabromobisphenol A 

TCP Tricresyl phosphate

TCEP Tris(chloroethyl) phosphate 

TCIPP Tris(2-chloroisopropyl) phosphate 

TDCIPP Tris(1,3-dichloro-2-propyl) phosphate 

TPHP Tris(phenyl) phosphate 

TLV® Threshold limit value

TWA Time-weighted average
Health Hazard Evaluation Report 2015-0050-3308 Page 1

Introduction

The Health Hazard Evaluation Program received a request from an electronics recycling 

company. The employer was concerned about possible employee exposures to flame retardant 

chemicals (flame retardants) and metals while recycling electronics. We first visited the 

company in March 2015. We met with employer and employee representatives and toured the 

workplace to observe operations, work practices, and working conditions. We also collected 

hand wipe samples for flame retardants for a pilot study to determine the need for repeated 

hand wipes to assess exposure. We returned in August 2015 to collect air, hand wipe, surface 

wipe, blood, and urine samples for metals and flame retardants. We provided our preliminary 

findings and recommendations to the employer and the employee representatives in letters in 

March 2015, September 2015, October 2015, and July 2016.

Background

Electronic devices contain many hazardous components including chemical flame retardants 

and heavy metals. Flame retardants are found in plastic and resin housings and components, 

wires, cable insulation, and circuit boards. They are also added to manufactured materials, 

surface finishes, and coatings to inhibit, suppress, or delay combustion and impede the spread 

of fire. Many electronics also contain dusts from sources such as carpet padding or office 

furniture foam that may contain flame retardants.

Polybrominated diphenyl ethers (PBDEs), tetrabromobisphenol A (TBBPA), and 

organophosphates are examples of flame retardants used in electronics. Recent observational 

epidemiological research concluded that PBDEs are associated with liver, thyroid, 

reproductive/developmental, and neurological effects [Dallaire et al. 2009; Grant et al. 2013]. 

Although PBDEs are no longer used in the manufacture of U.S. electronics, they will remain 

in the electronic recycling stream for decades. TBBPA, tris(phenyl) phosphate (TPHP), and 

other brominated flame retardants and organophosphate flame retardants will continue to be 

used and be present in the electronics recycling stream. Organophosphate flame retardants 

have been associated with adverse reproductive/developmental and neurological effects 

in animals [van der Veen and de Boer 2012]. We are able to measure levels of some flame 

retardant chemicals in blood and urine, but there is scientific uncertainty regarding the 

relationship between these levels in the body and specific health outcomes. More detailed 

information about flame retardants can be found in Appendix C.

Previous health hazard evaluations [NIOSH 2009a, 2014a] found employee exposures during 

electronic recycling, such as:

● lead from batteries, printed circuit boards, power cords, and cathode ray tubes

● cadmium from batteries, pigments, plastic stabilizers, metal coatings, and cathode 

ray tubes phosphors; and mercury from fluorescent lights, batteries, medical and 

telecommunication equipment, and some flat-panel displays

Electronic recycling employees may also be exposed to indium, a metal used in flat-panel 

displays and touchscreens. Employee overexposures and potential take-home exposures to 
Page 2 Health Hazard Evaluation Report 2015-0050-3308

metals in the electronics recycling industry have also been documented [Ceballos and Dong 

2016; Ceballos et al. 2016; Newman et al. 2015; NIOSH 2009a, 2014a]. More detailed 

information about lead and other metals can be found in Appendix C.

Process Description

The company began operations in an open warehouse in 2012. At the time of our evaluation, 

15 employees worked at the company. Their primary activities included recycling batteries, 

metals, cardboard, and ballast and capacitors for fluorescent lights. Other activities included 

(1) sorting, dismantling, and shredding electronic equipment such as computers, printers, 

keyboards, central processing units, circuit boards, fax machines, cameras, medical 

equipment, and photocopiers; and (2) secure data destruction of electronic medical records. 

The company did not recycle cathode ray tube monitors or fluorescent light bulbs, but 

did collect and ship them to another recycling company. Items not generally considered 

electronics, such as children’s toys and artificial Christmas trees, were also recycled.

Shipping and Receiving

Shipping and receiving involved processing paperwork associated with incoming electronics 

and unloading trucks. There was an office near the loading docks, and coordination was 

done in the shipping area and in the main office area with office staff. At times, shipping and 

receiving personnel would work in other locations, such as the optical sorter.

Shredding and Sorting

Large boxes of electronic components were moved by forklift and placed next to the shredder 

conveyor. Employees manually removed electronic components from the boxes and placed 

them onto a conveyor belt that carried them to the shredder (Figure 1). The shredded material 

then passed through a magnetic separator. The magnetic components were expelled from 

the separator to a conveyor belt where two or three employees separated copper wiring from 

its metal housing. Nonmagnetic scrap was further separated as it traveled through an eddy 

current separator. This primary shredder had local exhaust ventilation that extended from the 

shredder entrance to the eddy current separator. A smaller shredder was located in the center 

of the warehouse next to an optical sorter. This shredder and the optical sorter did not have 

local exhaust ventilation. The small shredder and optical sorter were in the same vicinity as 

the larger shredder.
Health Hazard Evaluation Report 2015-0050-3308 Page 3

Figure 1. Electronic shredding conveyor. Photo by NIOSH.

Three employees operated the optical sorter (Figure 2). Employees loaded the sorter with 

shredded material from both the small and large shredders, removed large boxes full of sorted 

material and cleaned underneath the optical sorter using a broom.

Figure 2. The discharge chute of the optical sorting machine. Photo by NIOSH.
Page 4 Health Hazard Evaluation Report 2015-0050-3308

Batteries and Disassembly

Two employees sorted expired batteries from their original packaging and removed 

batteries from electric toothbrushes. Five employees manually disassembled and separated 

computer components, such as circuit boards, hard drives, copper wiring, and other parts 

that contained valuable materials (Figure 3). Each employee worked at a station, selected 

a piece of electronic equipment, removed the screws, and separated the components. Two 

employees manually disassembled the electronic components and placed them on the 

conveyor belt or into a large box nearby. Another employee selected specific components for 

further disassembly. A fourth employee at the end of the conveyor separated the remaining 

components into one of four boxes located at the end of the conveyor. The fifth employee 

was primarily responsible for crushing and bailing the components using a bailing machine. 

Figure 3. Three of the five disassembly employees manually disassembling printers. 

Photo by NIOSH.

Office Work

Office employees primarily worked at a desk using a computer; however, they occasionally 

entered the recycling area briefly. 

Methods

We obtained informed consent from all participants before beginning the evaluation. We 

asked all participants to fill out a questionnaire about their pertinent personal, medical, and 

work history such as length of employment, job tasks, current practices, use of personal 

protective equipment (PPE), and hygiene practices. Our objectives were to evaluate flame 

retardants and metal exposures.

Flame retardants:

1. Evaluate different wipe materials and number of wipes.

2. Characterize employee exposures to selected flame retardants.
Health Hazard Evaluation Report 2015-0050-3308 Page 5

3. Compare the levels of selected flame retardants in employees’ blood and urine to 

levels in the general population.

4. Assess whether airborne and dermal exposures contribute to employees’ urine and 

blood levels of selected flame retardants.

Metals:

1. Characterize employee exposures to metals.

2. Assess whether employee exposures to airborne metals exceed applicable occupational 

exposure limits (OELs).

3. Assess whether employees’ blood lead and cadmium levels exceed biological 

exposure indices.

4. Evaluate the potential for take-home contamination from metals.

5. Evaluate the potential for generation of incidental nanoparticles, specifically indium.

Appendix A, Table A1 lists the flame retardants that we sampled for, where they are typically 

found, and when they are typically used, if used in electronics. Appendix A, Table A2 lists 

the three types of PBDE technical mixtures that we sampled for and their major congeners 

(a group of related chemicals). PBDE technical mixtures include pentabromodiphenyl 

ether (PentaBDE), octabromodiphenyl ether (OctaBDE), and decabromodiphenyl ether 

(DecaBDE). For some of our analyses, we divided the flame retardants into five categories on 

the basis of their usage in electronics.

Hand Wipe Samples for Flame Retardants

Hand wipes have been used in previous studies in homes or offices to measure dermal 

exposures to flame retardants. Watkins et al. [2013] found that flame retardant levels in 

hand wipes were significantly correlated with the same flame retardant in office dust and on 

office surfaces. Similarly, Hoffman et al. [2014] and Stapleton et al. [2014] found that the 

levels of some flame retardants on hand wipes were significantly correlated with house dust 

concentrations collected by vacuum. Research has also shown that the level of some flame 

retardants on hands significantly correlated with flame retardant levels in blood [Watkins et 

al. 2011] and were a better predictor of serum levels than house dust collected by vacuum 

[Stapleton et al. 2011]. Other research found that the hand wipe levels of flame retardants 

were significantly correlated with their urinary metabolites [Hoffman et al. 2014, 2015]. 

We conducted a pilot study in March 2015 comparing gauze and twill wipes (two 

commercially available wiping materials) and assessing the value of repeat hand wipes to 

design hand wipe procedures for flame retardants. See Appendix B for more details.

August 2015, we collected preshift and postshift hand wipe samples on 3 days for all 

15 employees (one employee was not present for hand wipes on Day 3). We collected the 

preshift samples as soon as the employees arrived in the office on consecutive days at the 

beginning of the week. No participants worked on the Saturday or Sunday prior to the 

evaluation. We collected the postshift samples before the employees washed their hands at 
Page 6 Health Hazard Evaluation Report 2015-0050-3308

the end of the work shift. We used gauze wipes and 99% isopropyl alcohol as the wetting 

agent. Each employee used only one set of hand wipes (for the palms of the hands and backs 

of the hands) because our pilot study showed sequential wiping dried the skin too much. The 

hand wipe procedures that we followed are outlined in Appendix B.

A contract lab analyzed all hand wipes flame retardants by ultra-performance liquid 

chromatography atmospheric pressure photoionization tandem mass spectrometry using 

methods previously described by LaGuardia et al. [2015]. All wipes were spiked with 

surrogate standards prior to extraction to determine the percent recovery for each type of 

flame retardant. The wipe sample results were surrogate corrected for percent recovery. 

The flame retardants we analyzed are listed below. We used the abbreviation standard for 

flame retardants proposed by Bergman et al. [2012]: 

● α-hexabromocyclododecane (α-HBCD)

● β-hexabromocyclododecane (β-HBCD)

● γ-hexabromocyclododecane (γ-HBCD)

● 2,4,4’-tribromodiphenyl ether (BDE-28)

● 2,2’,4,4’-tetrabromodiphenyl ether (BDE-47)

● 2,3’,4,4’-tetrabromodiphenyl ether (BDE-66)

● 2,2’,3,4,4’-pentabromodiphenyl ether (BDE-85)

● 2,2’,4,4’,5-pentabromodiphenyl ether (BDE-99)

● 2,2’,4,4’,6-pentabromodiphenyl ether (BDE-100)

● 2,2’,4,4’,5,5’-hexabromodiphenyl ether (BDE-153)

● 2,2’,4,4’,5,6’-hexabromodiphenyl ether (BDE-154)

● 2,2’,3,4,4’,5’,6-heptabromodiphenyl ether (BDE-183)

● 2,2’,3,3’,4,4’,5,5’,6-nonabromodiphenyl ether (BDE-206)

● decabromodiphenyl ether (BDE-209)

● 1,2-Bis(2,4,6-tribromophenoxy)ethane (BTBPE)

● decabromodiphenyl ethane (DBDPE)

● 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (EH-TBB)

● tetrabromobisphenol A (TBBPA)

● Bis(2-ethylhexyl) tetrabromophthalate (BEH-TEBP)

● tricresyl phosphate (TCP)

● Tris(chloroethyl) phosphate (TCEP)

● Tris(2-chloroisopropyl) phosphate (TCIPP)

● Tris(1,3-dichloro-2-propyl) phosphate (TDCIPP)

● Tris(phenyl) phosphate (TPHP)

Air Samples for Flame Retardants 

We collected full-shift personal air samples over 3 consecutive days on all 15 employees 

(one employee was not present for air samples on the last day). We do not report the results 
Health Hazard Evaluation Report 2015-0050-3308 Page 7

for the first day of air samples because a mistake was made during the collection of these 

samples. We collected the personal air samples for flame retardants on an Institute of 

Medicine sampler with a glass fiber filter at a nominal flow rate of 2 liters per minute. The 

sampler collects the inhalable fraction of particulates. A contract lab analyzed the samples for 

the same flame retardants that were analyzed from the hand wipes using a method developed 

by LaGuardia et al. [2015]. Flame retardants can be found as particulates or in a vapor phase, 

but we analyzed the flame retardants as particulates. Previous research has shown that more 

than 99% of organophosphate flame retardants in indoor air were found as particulates, and 

that TCEP and TCIPP were strongly associated with airborne particulates or adsorbed onto 

the filters due to polar interactions [Carlsson et al. 1997]. In addition, BDE-209 and the higher 

congeners of brominated flame retardants, such as BDE-99 and BDE-153, are predominately 

particulates [Allen et al. 2007]. BTBPE and TBBPA have also been found to be primarily in the 

particle-associated phase rather than the semivolatile phase [Sjödin et al. 2001]. 

Blood Samples for Flame Retardants and Lead 

and Cadmium

We collected approximately 30 milliliters (mL) of blood from 12 of the 15 employees at the 

end of their last shift of the work week. A trained technician drew venous blood from each 

participant into two serum separating tubes and one whole blood tube. Technicians followed 

universal precautions for working with blood and blood products specified by the Centers for 

Disease Control and Prevention [Siegel et al. 2007] and the Occupational Safety and Health 

Administration (OSHA) [OSHA 2003]. The tube of whole blood was sent to a commercial 

laboratory to be analyzed for blood lead, indium, and cadmium levels. We sent one tube 

of serum to the National Center for Environmental Health laboratory for quantification of 

PBDEs, polychlorinated biphenyls (PCBs), persistent pesticides (PPs), and cholesterol and 

triglycerides. PBDEs included BDE-17, BDE-47, BDE-85, BDE-99, BDE-100, BDE-128, 

BDE-153, BDE-154, BDE-183, and BDE-209. Cholesterol and triglycerides were measured 

to adjust brominated flame retardant, PCB, and PP levels for body fat. We sampled for 

PCBs and PPs to address the possibility of dietary effects on the levels of the PBDEs. If the 

participant gave consent, we stored a second serum tube for future research not related to the 

current health hazard evaluation.

Urine Samples for Flame Retardants

We collected preshift and postshift urine samples on each day that air and hand wipe sampling 

for flame retardants was performed for all 15 employees (one employee was not present for 

urine samples on the last day). Each urine sample was collected in a sterile 250-mL plastic 

cup. We measured the specific gravity of each sample, shook it, then transferred 30 mL to two 

separate containers. One container was sent to the National Center for Environmental Health 

laboratory for analysis of the following flame retardant metabolites:

● diphenyl phosphate (DPHP) – a metabolite of TPHP

● bis(l,3-dichloro-2-propyl) phosphate (BDCIPP) – a metabolite of TDCIPP

● bis(l-chloro-2-propyl) phosphate (BCIPP) – a metabolite of TCIPP

● bis(2-chloroethyl) phosphate (BCEP) – a metabolite of TCEP
Page 8 Health Hazard Evaluation Report 2015-0050-3308

● di-pcresylphosphate (DpCP) – a metabolite of TCP

● di-o-cresylphosphate (DoCP) – a metabolite of TCP

● 2,3,4,5-tetrabromobenzoic acid (TBBA) – a metabolite of EH-TBB

These analyses were conducted using the approach reported by Jayatilaka et al. [2017]. 

We used the reference range values in urine for the flame retardant metabolites for the U.S. 

population ages 20–59 as described in Ospina et al. [2018]. The second container was stored 

for future research if the employee gave us consent. 

Surface and Hand Wipe Samples for Metals

We collected and analyzed surface and hand wipe samples for metals according to National 

Institute for Occupational Safety and Health (NIOSH) Method 9102, including indium 

and neodymium [NIOSH 2018]. For surface samples, we used premoistened SKC Inc. 

Ghostwipe® towelettes to wipe surfaces outside of the processing areas of the plant. We 

used a 10 centimeter by 10 centimeter square disposable template to demarcate the surface 

sampling area at each sample location.

We evaluated the potential for take-home exposure to metals by collecting a postshift hand 

wipe sample from all 15 employees on 1 day. We used the same method previously described 

in Appendix B for flame retardants, except that we used the premoistened Ghostwipe 

towelettes instead of alcohol soaked wipes. We collected these hand wipe samples after the 

employee washed his or her hands at the end of the work shift. These samples were collected 

on a Friday prior to the start of the flame retardant portion of the study.

Air Samples for Metals

We collected personal and area air samples for metals and minerals, including indium 

and neodymium on 37 millimeter (mm) cassettes and analyzed them according to NIOSH 

Method 7303 [NIOSH 2018], with modification. The modification included wiping the 

interior walls of the filter cassette with the back side of the sample filter to collect particles 

on the inside of the cassette walls, as recommended by NIOSH [2016]. We collected these 

samples on the same days as the flame retardant samples.

We collected and analyzed full-shift area air samples for hexavalent chromium according to 

NIOSH Method 7605 [NIOSH 2018]. We collected these samples for 3 consecutive days in the 

area where employees loaded the conveyor and where the magnetic separator was located.

Air Samples for Particulate and Mercury Vapor

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

shredding operations of liquid crystal display (LCD) televisions, frames, boards, and other 

computer equipment. We used a TSI® model 3007 handheld condensation particle counter 

to count particles in the air, a TSI model 3330 optical particle sizer (OPS 3330) to measure 

the number and mass of particles, and a TSI DustTrak DRXTM Aerosol Monitor model 

8533 to simultaneously measure mass and size fraction of airborne particles. We placed the 

instruments at the outfeed of the sorter conveyor in the magnetic metals sorter area, about 
Health Hazard Evaluation Report 2015-0050-3308 Page 9

3 feet above the floor. We also collected particulate samples in the conference room for 

comparison to particle levels in the processing areas. Particulate samples were taken when 

the shredder was running, about 4.75 hours.

We used a Jerome® J505 atomic fluorescence mercury vapor analyzer to measure mercury 

vapor concentrations in the air in several storage locations and in the shredding process area. 

We took each sample for approximately 1 minute.

Detailed information about direct reading instrument operation is provided in Appendix D.

Air Samples for Nanomaterials

We collected area air samples using a MSP® M131 Micro-Orifice, Uniform Deposit 

Impactor (MOUDI) high flow impactor. The MOUDI M131 is a six-stage cascade impactor 

with aerosol cut point diameters of 10 micrometers (μm), 2.5 μm, 1.4 μm, 0.77 μm, 0.44 μm, 

and 0.25 μm. The aerosol cut point diameter is the size where 50% of the particles of that 

diameter are collected onto a filter, and the remaining particles pass through the impactor 

to the next smaller size-range stage and collection filter. The smallest cut point, 0.25 μm, 

is most similar to the engineered nanomaterial particle size range, for example the indium 

nanoparticles commonly found in LCD screens. We used the 2.5-μm cut point for respirable 

aerosols and the 10-μm cut point for inhalable-size aerosols. If inhaled, respirable particles 

can reach the deep (alveolar) region of the lung. 

Using the MOUDI we collected six air samples in the magnetic metals sorting area and six 

air samples inside the conference room for comparison and to determine if aerosol particles 

migrated from the processing area to the office area. We collected these samples on 75 mm 

diameter, 1.0 μm pore size, mixed cellulose ester membrane filters that were coated with 

silicone to help the particles adhere to the filter surface. The MOUDI operated at a flow rate 

of 100 liters per minute. We analyzed our air samples for indium, beryllium, cadmium, lead, 

manganese, neodymium, nickel, silver, tin, and titanium according to NIOSH Method 7303 

[NIOSH 2018].

Statistical Analysis

We used the American Industrial Hygiene Association IHstats V229 and SAS version 9.3 software 

for data analysis. Flame retardant wipe and air sample data were corrected for recoveries reported 

by the laboratory on three replicate spikes (100 nanograms per sample [ng/sample]) on blank 

wipes. For sample results that were reported as “not detected” we used the laboratory reporting 

limit divided by the square root of 2 [Hornung and Reed 1990] as the estimate. We examined the 

distributions of the air, hand wipe, and urine data. Some were normally distributed, some were log 

normally distributed, and some were neither; therefore, we reported medians, geometric means 

(GM), and ranges. We did not calculate GMs unless 70% or more of the samples had detectable 

results. We did not report medians or GMs if the sample size was five or less. Comparisons of 

medians or GMs were based simply on observation, not statistical testing. The reporting limits 

were 16 ng per sample for TCEP, TCIPP, and TDCIPP, 6.3 ng per sample of HBCD, and 

1 ng per sample for the remainder of the air samples. The reporting limits for hand wipe samples 

were 63 ng per sample for HBCD, 156 ng per sample for TCEP, TCIPP, and TDCIPP, and 
Page 10 Health Hazard Evaluation Report 2015-0050-3308

10 ng per sample for the remainder of the wipe samples. We assessed the efficiency of the repeat 

hand wipes by adding the sample results for each flame retardant from the three consecutive hand 

wipes, then calculated the percentage that was removed by each wipe. We compared the urine and 

serum levels of flame retardant biomarkers with the general population using the National Health 

and Nutrition Examination Survey (NHANES) data [ACGIH 2018; NIOSH 2014a; Ospina et al. 

2018; Sjodin et al. 2008]. We reported GMs for the study participants and the general population 

using relevant age ranges. 

Results

Participant Characteristics

All 15 employees participated in this evaluation; three were female. The average age was 37 

(range: 20–52) and the median length of time in this company was 15 months (range: 1 month to 

88 months). Participants usually worked a minimum of 40 hours per week, although on occasion 

they worked up to 45 hours. Duties involved disassembly (five participants), shredding (three), 

batteries (four), sorting (six), shipping/receiving (one), and office work (two). Some participants 

rotated to other duties as needed. Twelve participants reported wearing their work clothing 

home, and 13 reported wearing their work shoes or boots home. Seven of the 13 participants 

who worked in the processing area (all areas in the warehouse) reported always wearing gloves 

at work, three reported wearing them most of the time, two reported sometimes, and one 

employee did not report on the frequency of glove use. The company provided and required 

the use of gloves. All reported reusing their gloves. Cloth gloves were most commonly worn 

(six participants), followed by nitrile and cut-resistant gloves (three each), and leather gloves 

(one). Eight participants reported washing their hands four to five times per day at work, with 

the remainder washing their hands less frequently. One participant reported sometimes washing 

hands before eating at work, while 14 reported always washing their hands before eating at 

work. Twelve participants reported always washing their hands before leaving work, while three 

reported they sometimes washed their hands before leaving work. Six employees reported that 

they currently smoked. 

Hand Wipe Sampling for Flame Retardants

Pilot Hand Wipe Study (March 2015) 

We detected 19 of the 24 different flame retardants on each of the gauze and twill hand wipe 

samples. Table 1 shows that the median and range of the percent of total flame retardants 

removed by the sequential hand wipes were similar for the gauze and twill hand wipe 

materials. For both wipe materials, we found that the first set of two hand wipes removed 

the highest median percentage of total flame retardants. For individual flame retardants, we 

found that the percent removed by each of the three sequential wipe sets ranged from less 

than 5% to 98%. It is also likely that flame retardants remained on the hands even after the 

third sequential wipe. Therefore, the medians in Table 1 should be considered overestimates 

of the percent recovered. The alcohol was drying, and after three sets of wipes, the 

employees’ hands were white and irritated. A more detailed description and analysis of this 

pilot study will be provided in a separate manuscript. 
Health Hazard Evaluation Report 2015-0050-3308 Page 11

Table 1. Median and range of the percent of total flame retardants removed by gauze or 

twill hand wipes

Gauze wipes (n = 86)

Median of percent (range)

Twill wipes (n = 74)

Median of percent (range)

Percent removed by first wipe set 45 (4–98) 50 (1–89)

Percent removed by second wipe set 26 (1–55) 26 (5–93)

Percent removed by third wipe set* 23 (0–92) 23 (0–60)

*Because of laboratory analytical error we were unable to obtain results for 7 of the 19 detected

flame retardants on the third sequential wipes for 4 of the participants using gauze and 4 using 

twill. In addition, one of the twill participants was missing all of the measurements on the third wipe.

Hand Wipe Sampling (August 2015) 

Table 2 summarizes the results of the preshift and postshift hand wipe sampling for 22 of 

the 24 flame retardants taken on 3 subsequent days. We found no detectable (BDE-183) or 

very few detectable preshift or postshift hand wipes for OctaBDE flame retardant congeners 

(BDE-154, BDE-153). OctaBDE was not used in electronics after 2004. In contrast, we 

found that flame retardants commonly used in electronics (TPHP, TCP, DBDPE, and 

TBBPA) were detected in all of the postshift handwipe samples for processing employees. 

Additionally, postshift median levels of these flame retardants were higher than preshift 

levels. BTBPE, which is also commonly used in electronics, was not detected in all of the 

post shift samples. We also found that the median levels of BDE-209 was higher in the 

postshift handwipes than the preshift handwipes. We found these higher levels in the postshift 

handwipes of flame retardants commonly used in electronics and for BDE-209 in all four 

job task groups (shipping and receiving, sorting and shredding, batteries and disassembly, 

and office). Rarely used in electronics, PentaBDE (as represented by the congeners BDE-99, 

BDE-47, BDE-100, and BDE-85), was detected in most of the samples. The levels ranged 

from ND to 400 ng/sample. We did not report the results for BDE-66 and BDE-28, which 

are minor congeners for PentaBDE. TDICPP, which is also rarely used in electronics, had 

a median level of 5,590 ng/sample. The handwipe results for the flame retardants that are 

less commonly used in electronics now and in the past were varied. There was not much of 

a difference for the postshift medians for EH-TBB, BEH-TEBP, and TCEP and the preshift 

medians. TCIPP had a higher median in the post shift handwipe (965 ng/sample) than the 

preshift handwipe (965 ng/sample) for sorting and shredding.
Page 12 Health Hazard Evaluation Report 2015-0050-3308 Table 2. Preshift and postshift levels of 22 of the 24 flame retardants in hand wipe samples, by job task, in ng/sample Flame retardant Shipping and receiving (n = 3) % Detected range Sorting and shredding (n = 17) % Detected median range Batteries and disassembly (n = 18) % Detected median range Office (n = 6) % Detected median range Preshift Postshift Preshift Postshift Preshift Postshift Preshift Postshift OctaBDE (commonly used in electronics until around 2004) BDE-183 LOD = 10 0% 0% 0% 0% 0% 0% 0% 0% BDE-154*† LOD = 10 0% 0% 13%ND ND–24 13%ND ND–58 0% 11%ND ND–34 17%ND ND–27 17%ND ND–27 BDE-153* LOD = 10 0% 67% ND–45 6%ND ND–15 35%ND ND–45 6%ND ND–12 17%ND ND–38 17%ND ND–10 17%ND ND–11 OctaBDE and DecaBDE (commonly used in electronics until around 2013) BDE-209 LOD = 10 100% 180–570 100% 1,200–10,000 100% 332 93–2,000 100% 1,900 470–11,000 100% 358 83–2,300 100% 1,300 180–7,800 100% 191 30–14,000 100% 2930 81–22,000 BDE-206 LOD = 10 33% ND–21 100% 72–430 18%ND ND–150 71% 56.7 ND–440 22%ND ND–93 50% 36.2 ND–810 17%ND ND–950 50%132 ND–540 Commonly used in electronics now and in the past TPHP LOD = 10 100% 130–260 100% 1,400–4,400 100% 341 110–800 100% 3,100 500–11,000 94%170 ND–800 100% 1,000 59–3,600 100% 105 77–300 83%487 ND–640 TCP LOD = 10 100% 63–140 100% 810–1,900 100% 187 50–430 100% 1,500 230–6,000 89% 95.3 ND–390 100% 270 32–4,400 83% 39.3 ND–77 67%174 ND–320 BTBPE LOD = 10 67% ND–110 100% 270–4,300 71% 23.1 ND–110 100% 319 46–1,300 33%ND ND–98 89% 62.8 ND–530 0% 50% 25.8 ND–84 DBDPE LOD = 10 100% 41–110 100% 630–4,600 100% 137 35–1,600 100% 1,500 96–7,900 100% 57.9 20–500 100% 310 60–3,100 67% 21.5 ND–38 100% 93.6 28–730 TBBPA LOD = 10 100% 96–230 100% 590–2,200 94%156 ND–610 100% 1,300 77–3,300 94% 89.1 ND–330 100% 365 25–3,400 100% 40.4 31–200 83%299 ND–1,100
Health Hazard Evaluation Report 2015-0050-3308 Page 13 Table 2 Continued. Preshift and postshift levels of flame retardants in hand wipe samples, by job task, in ng/sample Flame retardant Shipping and receiving (n = 3) % Detected range Sorting and shredding (n = 17) % Detected median range Batteries and disassembly (n = 18) % Detected median range Office (n = 6) % Detected median range Preshift Postshift Preshift Postshift Preshift Postshift Preshift Postshift Less commonly used in electronics now and in the past EH-TBB LOD = 10 100% 81–130 100% 91–140 100% 72.6 17–470 94% 42.7 ND–170 100% 52.0 20–190 78% 32.8 ND–220 100% 47.6 35–100 100% 37.0 22–100 BEH-TEBP LOD = 10 100% 86–200 100% 210–970 100% 79.2 16–1,700 100% 107 45–3,600 100% 70.0 16–1,100 94% 99.0 ND–5,900 100% 93.5 15–140 100% 118 20–410 TCEP LOD = 156 0% 33% ND–108 0% 24%ND ND–310 0% 6%ND ND–250 17%ND ND–190 0% TCIPP LOD = 156 100% 370–470 100% 500–920 53%181 ND–1,500 88%965 ND–4,600 61%179 ND–850 67%295 ND–560 100% 600 320–1,300 83%196 ND–450 HBCD (α,β,γ) LOD = 63 0% 0% 0% 0% 0% 0% 0% 0% Rarely used in electronics§ PentaBDE BDE-99 LOD = 10 100% 34–65 100% 170–370 100% 44.1 19–340 100% 95.0 26–160 94%52 ND–230 94% 54.2 ND–370 100% 48.2 19–230 100% 50.5 28–110 BDE-47 LOD = 10 100% 26–55 100% 130–400 88% 30.0 ND–230 88% 59.5 ND–120 83% 40.0 ND–190 94% 27.5 ND–170 67% 45.0 ND–230 100% 27.8 12–130 BDE-100 LOD = 10 33% ND–14 100% 27–97 18%ND ND–53 47%ND ND–28 56% 12.1 ND–33 28%ND ND–60 50% 13.8 ND–30 50% 7.19 ND–23 BDE-85 LOD = 10 0% 33% ND–17 6%ND ND–25 0% 0% 0% 0% 0% TDCIPP LOD = 156 100% 1,000–1,500 100% 1,100–1,500 94%577 ND–2,400 100% 1,000 170–5,300 94%455 ND–3,600 100% 722 210–2,900 100% 683 380–1,500 100% 5,590 180–19,000 LOD = Limit of detection *Also present in PentaBDE in small amounts †The n for BDE-154 is 2 preshift and 3 post shift for shipping and receiving, 16 preshift and 15 post shift for sorting and shredding, 17 preshift and 18 post shift for batteries and disassembly, and 6 for office. §Primarily used in polyurethane foam and commonly present in dust
Page 14 Health Hazard Evaluation Report 2015-0050-3308

Air Samples for Flame Retardants

Results of personal air sampling for 22 of the 24 flame retardants are listed in Table 3, 

in nanograms per cubic meter of air (ng/m3). PBDEs are listed by technical mixture (i.e., 

OctaBDE) and by decreasing concentration of each congener within that mixture. BDE-209 

had the highest GM concentration and the largest range of concentrations across the 

15 participants. DecaBDE is composed of 97%–98% BDE-209, while OctaBDE is composed 

of 1%–50% BDE-209 [Alaee et al. 2003; La Guardia et al. 2006]. BDE-183 is present in 

concentrations ranging from 13%–43% in OctaBDE, and considered a marker for OctaBDE 

because it is not present in either PentaBDE or DecaBDE. BDE-183 and BDE-154 were 

not detected in any air samples. This indicates that the likely source of the BDE-209 was 

DecaBDE (see Appendix A, Table A2). The next highest GM concentration was TPHP 

followed by TCP then DBDPE. We did not find BDE-85, α-HBCD, β-HBCD, γ-HBCD, 

TCEP, TCIPP, or TDCIPP in any of the personal air samples.

Results of personal air sampling for flame retardants, stratified by job tasks performed during 

sampling, are in Table 4. We detected the flame retardant congeners in about 80% of the air 

samples for those flame retardants commonly used in electronics until 2013 as well as those 

used commonly in electronics now and in the past, regardless of job task. Some of the flame 

retardants less commonly used in electronics (EH-TBB and BEH-TEBP) and some not 

generally used in electronics, but primarily used in polyurethane foam (BDE-99, BDE-47, 

and BDE-100) were also found in all or nearly all of the air samples, but at a median 

concentration of ≤ 11 ng/m3 overall. The highest airborne concentrations of BDE-209 

occurred in the shipping and receiving department and the sorting and shredding department. 

In general, the highest concentrations of flame retardants occurred in the sorting and 

shredding job tasks. The lowest concentrations were in the office. 
Health Hazard Evaluation Report 2015-0050-3308 Page 15

Table 3. Full-shift personal air sampling results for 15 participants over 2 days (n = 29), in ng/m3

Flame retardant, MDC Median Geometric mean (GM) (range) # (%) detected

OctaBDE (commonly used in electronics until around 2004)

BDE-183, MDC = 0.9 ND ND 0 (0)

BDE-154†, MDC = 0.9 ND ND 0 (0)

BDE-153†, MDC = 0.9 ND (ND–14) 5 (17)

OctaBDE and DecaBDE (commonly used in electronics until around 2013)

BDE-209, MDC = 0.9 142 189 (29–3,600) 29 (100)

BDE-206, MDC = 0.9 4.03 4.65 (ND–240) 23 (79)

Commonly used in electronics now and in the past

TPHP, MDC = 0.9 148 117 (ND–1,800) 28 (97)

TCP, MDC = 0.9 110 110 (ND–1,900) 28 (97)

DBDPE, MDC = 0.9 54.7 62.1 (2.8–630) 29 (100)

BTBPE, MDC = 0.9 10.2 (ND–140) 20 (69)

TBBPA, MDC = 0.9 ND (ND–86) 5 (17)

Less commonly used in electronics now and in the past

EH-TBB, MDC = 0.9 5.79 6.49 (2.0–110) 29 (100)

BEH-TEBP, MDC = 0.9 4.92 5.60 (ND–40) 28 (97)

TCEP, MDC = 14 ND ND 0 (0)

TCIPP, MDC = 14 ND ND 0 (0)

HBCD (α,β,γ), MDC = 6 ND ND 0 (0)

Rarely used in electronics‡

PentaBDE

BDE-99, MDC = 0.9 10.6 11.7 (6.0–63) 29 (100)

BDE-47, MDC = 0.9 3.84 4.45 (ND–44) 26 (90)

BDE-100, MDC = 0.9 3.37 3.34 (1.5–9.1) 29 (100)

BDE-85, MDC = 0.9 ND ND 0 (0)

TDCIPP, MDC = 14 ND ND 0 (0)

MDC = minimum detectable concentration

ND = not detected

†Also present in PentaBDE in small amounts 

‡Primarily used in polyurethane foam and commonly present in dust
Page 16 Health Hazard Evaluation Report 2015-0050-3308

Table 4. Concentrations of flame retardants in full-shift personal air samples, by job task, in ng/m3

Flame 

retardant, 

MDC

Shipping and 

receiving (n = 2*)

% Detected

(range)

Sorting and 

shredding (n = 12) 

% Detected

Median (range)

Batteries and 

disassembly (n = 11) 

% Detected

Median (range)

Office (n = 4*)

% Detected

(range)

OctaBDE (commonly used in electronics until around 2004)

BDE-183

MDC = 0.9

0% 0% 0% 0%

BDE-154†

MDC = 0.9

0% 0% 0% 0%

BDE-153†

MDC = 0.9

50%

(ND–2.7)

25%

ND (ND–14)

9%

ND (ND–3.6)

0%

OctaBDE and DecaBDE (commonly used in electronics until around 2013)

BDE-209

MDC = 0.9

100%

(290–2,400)

100%

329 (29–3,600)

100%

114 (43–500)

100%

(43–240)

BDE-206

MDC = 0.9

100%

(11–67)

92%

7.68 (ND–240)

64%

1.65 (ND–16)

75%

(ND–5.5)

Commonly used in electronics now and in the past

TPHP

MDC = 0.9

100%

(48–290)

100%

259 (68–1,800)

100%

137 (2.1–710)

75%

(ND–50)

TCP

MDC = 0.9

100%

(120–150)

100%

208 (70–1,900)

91%

85.9 (ND–650)

100%

(29–38)

DBDPE

MDC = 0.9

100%

(15–170)

100%

145 (24–540)

100%

42.9 (2.8–630)

100%

(14–80)

BTBPE

MDC = 0.9

50%

(ND–35)

83%

25.2 (ND–140)

82%

9.93 (ND–56)

0%

TBBPA

MDC = 0.9

0% 8%

ND (ND–86)

18%

ND (ND–10)

50%

(ND–10)

Less commonly used in electronics now and in the past

EH-TBB 

MDC = 0.9

100%

(9.2–30)

100%

6.79 (2.0–110)

100%

4.52 (2.0–30)

100%

(3.1–8.5)

BEH-TEBP 

MDC = 0.9

100%

(6.7–22)

100%

7.44 (1.5–40)

91%

3.35 (ND–13)

100%

(1.6–4.9)

TCEP

MDC = 14

0% 0% 0% 0%

TCIPP

MDC = 14

0% 0% 0% 0%

HBCD (α,β,γ)

MDC = 6

0% 0% 0% 0%

Rarely used in electronics‡

PentaBDE

BDE-99

MDC = 0.9

100%

(23–37)

100%

11.9 (6.4–63)

100%

8.39 (6.0–29)

100%

(8.1–11)

BDE-47

MDC = 0.9

100%

(14–15)

92%

5.84 (ND–44)

91%

3.28 (ND–17)

75%

(ND–3.0)

BDE-100

MDC = 0.9

100%

(7.2–9.1)

100%

3.36 (1.9–6.9)

100%

2.87 (1.5–5.4)

100%

(2.5–3.6)

BDE-85

MDC = 0.9

0% 0% 0% 0%

TDCIPP 

MDC = 14

0% 0% 0% 0%

Note: These MDCs were calculated using an average volume of 1,043 liters.

*Median not calculated if n = 5 or less

†Also present in PentaBDE in small amounts 

‡Primarily used in polyurethane foam and commonly present in dust
Health Hazard Evaluation Report 2015-0050-3308 Page 17

Blood Samples for Flame Retardants

Of the fifteen employees, 12 had blood drawn for metals and PBDEs. Table 5 shows the 

serum PBDE concentrations in our participants for 10 different polybrominated flame 

retardants. The table also shows the serum PBDE concentrations found in the NHANES, 

which is a representative sample of the general population. The highest median and 

GM serum PBDE concentrations in our participants were for BDE-47, BDE-153, and 

BDE-209. In addition all 12 of the participants had BDE-153, BDE-47, and BDE-100 

detected in their blood serum. The GM concentration of BDE-209 was 8.1 nanograms per 

gram (ng/g) lipid weight in our participants, which was above the LOD of 5.8 ng/g lipid 

weight in the NHANES. One of the office participants had serum BDE-209 concentrations 

less than the LOD of 4.8 ng/g lipid weight; the other did not have blood tests. 

Table 5. PBDE concentrations in serum of electronics recycling employees and in the National 

Health and Nutrition Examination Survey, in ng/g lipid weight

Electronics recycling company 

participants (n = 12)

National Health and 

Nutrition Examination Survey*†

Median GM‡ Max Median GM 95th 

percentile

OctaBDE (commonly used in electronics until around 2004)

BDE-183 0.542 (-) 1.40 Not 

reported

ND (< 1.7) ND (< 1.7)

BDE-154§ 0.533 (-) 1.43 Not 

reported

ND (< 0.8) 4.20

BDE-153§ 8.19 8.39 32.4 4.40 5.41 73.3

OctaBDE and DecaBDE (commonly used in electronics until around 2013)

BDE-209¶ 8.36 8.10 14.8 Pooled sample; no mean calculated due to 

high proportion of ND (< 5.8)

PentaBDE (rarely used in electronics)**

BDE-99 3.84 3.08 13.8 Not 

reported

ND (< 5.0) 41.6

BDE-47 16.4 13.5 49.1 18.0 19.5 163.0

BDE-100 4.20 3.31 9.81 3.30 3.77 36.6

BDE-85 0.465 (-) 1.44 Not 

reported

ND (< 2.4) 4.10

*Age 20 and older

†Samples taken 2003 and 2004

‡GM not calculated if n = 5 or less

§Also present in PentaBDE in small amounts.

¶Data from 2007–2008 NHANES

**Primarily used in polyurethane foam and commonly present in dust
Page 18 Health Hazard Evaluation Report 2015-0050-3308

We sampled for PCBs and PPs to address the possibility of dietary effects on the levels of the 

PBDEs. Appendix A, Tables A5 and A6 show the concentrations of serum PCBs and PPs in 

our participants and the concentrations found in NHANES. With the exception of PCB-28, 

all were lower in our participants than in NHANES. The higher PCB-28 concentration may 

reflect occupational exposure to PCBs, but this was beyond the scope of this evaluation. 

Urine Samples for Flame Retardants

The results of urine testing for metabolites of certain flame retardants divided by departments 

are shown in Table 6 (uncorrected concentrations in micrograms per liter [μg/L]) and Table 

7 (creatinine corrected concentrations in micrograms per gram [μg/g] creatinine). Creatinine 

correction is done to adjust for individual variation in urine concentration. Sorting and 

shredding participants had close to double the median concentration of DPHP, the metabolite 

of TPHP, in their urine postshift compared to preshift. This was true when looking at 

creatinine corrected or uncorrected results. Concentrations of DPHP were similar preshift and 

postshift among shipping and receiving, and among batteries and disassembly participants. 

They declined across the shift in office participants. We compare the results for the third day 

post shift urinary metabolite measurements for the electronics recycling company employees 

to the general population in Appendix A, Table A7 (uncorrected concentrations in μg/L) and 

Table A8 (creatinine corrected concentrations in μg/g creatinine).

DpCP and DoCP, metabolites of TCP, were undetectable in most participants. We detected no 

TBBA, the metabolite of EH-TBB, in the urine of any participants. Median concentrations 

of BCEP, the metabolite of TCEP, increased slightly across the shift among sorting and 

shredding, and batteries and disassembly participants. BDCIPP, the metabolite of TDCIPP, 

was detected in all urine samples, and median concentrations decreased slightly across shift 

for all categories of participants.
Health Hazard Evaluation Report 2015-0050-3308 Page 19 Table 6. Uncorrected concentrations of flame retardant metabolites in urine samples, by job task, in μg/L Metabolite (parent flame retardant) Shipping and receiving (n = 3*) % Detected range Sorting and shredding (n = 17) % Detected median range Batteries and disassembly (n = 16–18) % Detected median range Office (n = 6) % Detected median range Preshift Postshift Preshift Postshift Preshift Postshift Preshift Postshift Commonly used in electronics now and in the past DPHP (TPHP) LOD = 0.16 100% 1.0–1.8 100% 0.89–2.1 100% 1.62 0.69–4.3 100% 3.48 1.3–7.1 100% 1.40 0.51–5.4 89% 1.57 ND–9.2 100% 1.04 0.64–2.4 83% 0.379 ND–1.2 DpCP (TCP) LOD = 0.05 0% 33% ND–0.06 29%ND ND–0.15 35%ND ND–0.21 6%ND ND–0.06 33%ND ND–0.11 0% 0% DoCP (TCP) LOD = 0.05 0% 0% 0% 0% 0% 0% 0% 0% Less commonly used in electronics now and in the past TBBA (EH-TBB) LOD = 0.05 0% 0% 0% 0% 0% 0% 0% 0% BCEP (TCEP) LOD = 0.08 100% 0.29–2.3 100% 0.38–0.65 94% 0.676 ND–1.6 100% 0.792 0.21–2.2 75% 0.367 ND–1.2 94% 0.586 ND–1.9 100% 1.09 0.27–2.5 100% 0.436 0.21–0.63 BCIPP (TCIPP) LOD = 0.10 100% 0.23–1.3 33% ND–0.77 35%ND ND–2.6 35%ND ND–2.4 22%ND ND–1.5 22%ND ND–12 50% 0.263 ND–0.97 33%ND ND–0.50 Rarely used in electronics† BDCIPP (TDCIPP) LOD = 0.11 100% 3.9–8.5 100% 2.5–6.1 100% 2.50 0.66–5.2 100% 2.43 0.47–4.4 100% 1.75 0.36–6.7 100% 1.57 0.15–12 100% 5.82 1.7–15 100% 3.16 0.31–11 *Median not calculated if n = 5 or less †Primarily used in polyurethane foam and commonly present in dust
Page 20 Health Hazard Evaluation Report 2015-0050-3308 Table 7. Creatinine corrected concentrations of flame retardant metabolites in urine samples, by job task, in μg/g creatinine Metabolite (parent flame retardant) Shipping and receiving (n = 3*) % Detected range Sorting and shredding (n = 17) % Detected median range Batteries and disassembly (n = 16–18) % Detected median range Office (n = 6) % Detected median range Preshift Postshift Preshift Postshift Preshift Postshift Preshift Postshift Commonly used in electronics now and in the past DPHP (TPHP) 100% 0.52–0.73 100% 0.56–0.86 100% 0.868 0.39–2.3 100% 1.76 0.41–4.3 100% 0.913 0.26–2.4 89% 0.973 ND–3.0 100% 0.507 0.38–0.81 83% 0.345 ND–0.74 DpCP (TCP) 0% 33% ND–0.03 29%ND ND–0.10 35%ND ND–0.09 6%ND ND–0.05 33%ND ND–0.23 0% 0% DoCP (TCP) 0% 0% 0% 0% 0% 0% 0% 0% Less commonly used in electronics now and in the past TBBA (EH-TBB) 0% 0% 0% 0% 0% 0% 0% 0% BCEP (TCEP) 100% 0.20–0.90 100% 0.16–0.48 94% 0.358 ND–0.87 100% 0.372 0.17–0.81 75% 0.282 ND–0.76 94% 0.355 ND–0.92 100% 0.540 0.15–1.3 100% 0.424 0.19–0.58 BCIPP (TCIPP) 100% 0.16–0.50 33% ND–0.31 35%ND ND–0.83 35%ND ND–0.64 22%ND ND–0.97 22%ND ND–4.8 50% 0.142 ND–0.45 33%ND ND–0.29 Rarely used in electronics† BDCIPP (TDCIPP) 100% 2.3–3.5 100% 1.5–2.5 100% 1.23 0.54–2.4 100% 1.02 0.54–2.7 100% 1.14 0.20–5.2 100% 0.920 0.06–4.5 100% 2.14 0.85–8.3 100% 2.11 0.62–7.0 *Median not calculated if n = 5 or less †Primarily used in polyurethane foam and commonly present in dust
Health Hazard Evaluation Report 2015-0050-3308 Page 21

Surface Samples for Metals

We wiped surfaces outside of the processing area to determine if metals were inadvertently 

transferred or had migrated from the processing area. Our results showed the presence of metals 

on most of these surfaces (Table 8). However, we found that the levels of lead and manganese 

on the air diffuser in the conference room and on the employee water cooler handle were more 

than five times greater than on the other surfaces. Levels of nickel were highest on the men’s 

office bathroom door handle and on the handle of the tap water cooler at the employee entrance.

Table 8. Surface wipe samples for selected metals in nonprocessing locations, in μg/100 cm2

Sample location* Cadmium Lead Manganese Nickel

Coffee table top 0.066 2.7 1.4 0.52

Men’s bathroom door handle (in the office)† 0.056 1.2 0.83 7.4

Floor, conference room entrance from office 0.07 2.4 2 0.72

Conference room supply air diffuser 0.68 30 13 3.2

Men’s bathroom in processing area 0.044 0.83 0.47 0.34

Breakroom table top ND 0.32 0.11 ND

Breakroom microwave table top 0.11 3.8 2.4 1.2

Breakroom microwave keypad ND ND 0.23 0.35

Employee entrance, water cooler (handle)† 0.81 21 15 6.8

Locker room, next to locker handle 0.036 0.63 0.3 0.64

Employee desk by computer mouse ND 0.32 ND 0.072

Employee keyboard† 0.063 3.6 1.7 0.59

Limit of detection 0.02 0.3 2 0.07

μg/100 cm2 = Micrograms per 100 square centimeters

ND = Not detected, results were below the limit of detection.

*Unless otherwise noted, the surface sampling area was 100 cm2.

†Estimated surface area
Page 22 Health Hazard Evaluation Report 2015-0050-3308

Hand Wipe Samples for Metals

We detected metals on the hands of all processing employee participants after they washed 

their hands before leaving work at the end of the shift (Table 9). We found that lead had the 

highest mean and median concentrations in the hand wipes. 

Table 9. Hand wipe sample results for all employee (n = 12) in 

μg/sample for selected metals

Element Mean concentration 

(range)

Median 

concentration

Cadmium 0.45 (0.032–1.4) 0.33

Lead 12 (0.57–37) 7.5

Manganese 8.3 (0.54–34) 4.6

Nickel 3.0 (0.39–7.4) 2.5

Air Samples for Metals

We collected personal air samples for 30 elements for 15 employees over 3 days and then 

calculated summary statistics about these exposures (Appendix A, Table A3). One employee 

working in batteries and disassembly was exposed to airborne cadmium above the NIOSH 

recommended exposure limit (REL) of 5 micrograms per cubic meter (μg/m3

). The remaining 

cadmium exposures (GM 0.09 μg/m3

) were well below the lowest OEL. No employees 

were exposed to lead concentrations above the OEL of 50 μg/m3

; however, an employee 

working on the shredder had an airborne lead exposure of 19 μg/m3

. The highest manganese 

concentration, 45 μg/m3, is about half the lowest OEL of 100 μg/m3

. Median indium 

concentrations were very low overall (0.2% of the OEL). Calcium, magnesium, strontium, 

and titanium concentrations were all 100 times below the OEL. We did not detect arsenic 

(< 0.73 μg/m3

) or tellurium (< 0.42 μg/m3), and with the exception of one sample 

(0.31 μg/m3

) all molybdenum samples were not detectable (< 0.08 μg/m3). Phosphorous 

(< 2.08 μg/m3

), selenium (< 0.42 μg/m3), thallium (< 0.83 μg/m3), and vanadium 

(< 0.06 μg/m3

) were not detected in most samples. 

Table 10 shows the concentrations of cadmium, lead, manganese, and nickel in personal 

air samples by job task. The highest GM lead and manganese concentrations occurred 

during sorting and shredding. The highest GM cadmium concentrations occurred in the 

shredding and the disassembly participants. However, one of the employees in batteries 

and disassembly had cadmium exposures above the NIOSH REL. Even though the office 

participants rarely entered the warehouse, they had detectable concentrations of metals in 

their air samples.
Health Hazard Evaluation Report 2015-0050-3308 Page 23

Table 10. Geometric mean and range of concentrations of metals in personal air samples, by 

job task, in μg/m3

Location Cadmium Lead Manganese Nickel

GM Range GM Range GM Range GM Range

Shipping and 

receiving 

(n = 3)

0.046 0.02–0.08 1.61 0.89–2.5 1.02 0.56–1.6 0.42 0.26–0.58

Sorting and 

shredding

(n = 15)

0.136 0.05–0.39 5.81 2.4–19 7.09 1.5–45 2.00 0.87–5.5

Batteries and 

disassembly 

(n = 19)

0.106 0.05–6.4 1.43 0.93–2.8 0.857 0.59–1.8 0.397 0.17–0.94

Office

(n = 6)

0.023 0.0070–0.48 0.480 0.27–0.91 0.250 0.13–0.47 0.130 0.060–0.39

We took area air samples for metals in three processing locations and an area air sample in 

the conference room where we expected less airborne metals. Table 11 shows the results for 

cadmium, lead, manganese, and nickel. Lead and cadmium concentrations were highest near 

the infeed of the shredder, and manganese and nickel were highest at the sorting end of the 

shredder. Concentrations of all four metals were lower in the disassembly area. The airborne 

area metal concentrations in the conference room were below the concentrations we measured 

in the processing areas. We did not detect hexavalent chromium in any area air samples.

Table 11. Area air sample results for metals over 3 sampling days, in μg/m3 

Location Cadmium Lead Manganese Nickel

GM Range GM Range GM Range GM Range

Infeed of 

shredder

0.15 0.07–0.54 6.9 2.6–25 4.4 1.6–15 1.2 0.40–3.1

Sorting end 

of shredder

0.059 0.04–0.08 3.2 2.3–4.1 8.1 6.4–9.9 2.5 1.3–5.7

Batteries 

and 

disassembly 

0.068 0.04–0.14 1.2 1.2–1.3 0.70 0.64–0.74 0.52 0.24–2.3

Conference 

room

0.015 0.01–0.02 0.29 0.21–0.46 0.16 0.14–0.17 0.060 0.06–0.07
Page 24 Health Hazard Evaluation Report 2015-0050-3308

Mercury Vapor Sampling Results

We found mercury vapor present in several locations in the warehouse and recycling process 

areas (Table 12). The highest level was measured in the magnetic metals sorting bin, only a 

few inches above the metal scrap. 

Table 12. Mercury vapor direct-reading spot measurement 

results, in μg/m3

Sample location description Result

Breakroom 3.5

Feeder area of shredding process 4.9

Feeder area of shredding process 5.9

Magnetic metals sorting area, at height of 

scrap bin opening

9.5

Magnetic metals sorting area, inches above 

metal scrap

28

Magnetic metals sorting area, about a foot 

above metal scrap

13

Shredded glass and plastic sorting area 2.6

Bin of LCD screens 0.55

Bin of fluorescent lights 0.64

Direct-Reading Particulate Measurement Results

We measured higher concentrations of particulates in the processing area near the magnetic 

metals sorting operations compared to the conference room, a nonprocessing area. In general, 

the nonprocessing concentrations remained steady throughout the sampling period (4 hours

45 minutes). In contrast, particle concentrations in the magnetic metals sorting area varied

and increased above background levels during shredding, emptying metal scrap bins, and 

dumping aluminum and plastic scraps into bins. 

Airborne particle concentrations in the magnetic metals sorting area increased when a 

pedestal floor fan was turned on to cool employees. Employees were picking magnetic metal

scraps off the conveyor belt and sorting them into other bins for further recycling. The fan 

blew air across the metal scrap conveyor belt toward employees (Figure 4). The directreading instruments also measured a particle increase when the bin containing the magnetic 

metals was moved.
Health Hazard Evaluation Report 2015-0050-3308 Page 25

Figure 4. Cooling fan blowing air across sorting belt toward employee.

Figure 5 compares particulate concentrations in the conference room to the magnetic metals 

sorting area concentrations. The conference room particulate concentration remained mostly 

steady throughout the sampling period. In the magnetic metals sorting area, particulate 

concentrations fluctuated but were generally above the conference room levels, especially for 

particles less than 1 μm in diameter. For a brief period of time, the magnetic metals sorting 

area had lower particulate concentrations when compared to the conference room. This 

corresponded to when the employees were on a break and no activities were occurring 

in the area.
Page 26 Health Hazard Evaluation Report 2015-0050-3308

Figure 5. Comparison of total particulate concentrations in the magnetic metals sorting area and 

conference room as measured by the OPS3330 direct-reading particulate monitor.

A comparison of 0.3 μm sized particle concentration from the OPS3330 showed that the 

magnetic metals sorting area and conference room had similar particle concentrations 

(Figure 6), except for a 1-hour period during which particle concentrations in the magnetic 

metal sorting area fluctuated several times above concentrations in the conference room.

Figure 6. Comparison of 0.3 μm particle concentrations in the magnetic metals sorting area and

conference room.
Health Hazard Evaluation Report 2015-0050-3308 Page 27

Size-selective Filter-based Air Sample Results

Table A4a and A4b in Appendix A show the size-selective area air sample results. In the 

magnetic metals sorting area we did not detect indium or indium compounds (< 0.02 μg/m3) in 

the smaller sizes (0.25 μm, 0.44 μm, and 0.77 μm) but we did detect indium in the larger sizes 

(1.4 μm, 2.5 μm, and 10 μm). We did not detect indium (< 0.02 μg/m3) in the conference room 

in any of the size ranges. 

We found detectable amounts of manganese and titanium in all size ranges of the air samples 

collected in the processing area. We found detectable levels of lead, nickel, silver, and tin in 

all stages except the 0.25 μm cut point. In addition, we found cadmium and neodymium in all 

stages above the 0.44 μm cut point. Beryllium was not detected above the MDC in any of the 

processing area size-selective samples. 

In the size-selective air sample collected in the conference room, we did not find beryllium, 

indium, and neodymium above their respective MDCs. In contrast, manganese and titanium 

were detected at every cut point. Cadmium, lead, nickel, silver, and tin were detected in 

respirable size cut points. 

Blood Samples for Metals

Blood lead levels (BLLs) ranged from 0.99 micrograms per deciliter (μg/dL) to 12 μg/dL. 

The NIOSH Adult Blood Lead Epidemiology and Surveillance System uses a surveillance 

case definition for an elevated BLL in adults of 5 μg/dL of blood or higher [CDC 2015a]. 

Three BLLs were over 5 μg/dL (6.7, 7.0, and 12.0 μg/dL) in the shredding and sorting areas.

Blood cadmium levels were low, with all but two below the laboratory LOD of 0.5 μg/L. The 

other two were below 1 μg/L in shredding and in sorting. OSHA defines an acceptable blood 

Table 13. Average mass concentrations* in mg/m3 from the 

DustTrak for different size cut points

DustTrak cut point size bin Average mass concentration

1 μm 0.21

2.5 μm 0.22

4 μm 0.24

10 μm 0.41

mg/m3 = Milligrams per cubic meter

*From the magnetic metals sorting area

Table 13 compares the mass concentration of four different particulate sizes. Particulates 

greater than 10 μm diameter had the largest mass concentration. We did not see any 

differences between particulate mass concentrations in the nanoscale and respirable size 

fractions of 1 μm, 2.5 μm, and 4 μm.
Page 28 Health Hazard Evaluation Report 2015-0050-3308

cadmium level as less than 5 μg/L. The GM blood cadmium level in a large representative 

sample of the general population was 0.337 μg/L, with a 95th percentile of 1.70 μg/L [CDC 

2015b]. All serum indium levels were below the LOD of 0.5 μg/L.

Workplace Observations

PPE included safety glasses, steel-toed boots, and cut-resistant gloves. Ear plugs and hard 

hats were required for working around the shredder, but optional in other areas. Some 

employees voluntarily wore cut resistant sleeves and N95 filtering facepiece respirators. 

Employees had received a copy of Appendix D of the OSHA respiratory protection standard 

(29 Code of Federal Regulation [CFR] 1910.134). We observed some employees working 

at the metal sorter wearing their respirators incorrectly (e.g., not wearing the lower strap). 

Employees were permitted to have water bottles and other drinks on the processing floor 

even though they had a break room. We also saw employees dry sweeping in the processing 

area, a practice that can re-aerosolize dust. The company did not provide uniforms or have 

shower facilities, laundry facilities, or locker rooms. Employees were permitted to wear their 

work clothes home. The employees ate lunch inside a breakroom. 

Discussion

Metals

Surface levels of metals in the conference room were lower than those found in the 

processing areas, but we found relatively higher levels on the supply air diffuser in the 

conference room. This likely occurred because the office area and conference room air intake 

was located inside the warehouse, and dusts containing metal deposited on the supply air 

diffuser as air entered the conference room. In addition, we found metals, including lead, 

in the conference room air samples, which emphasizes the need for a separate ventilation 

system. According to ANSI/ASHRAE Standard 62.1-2016, air with potentially dangerous 

particles such as lead or other heavy metals should never be recirculated or transferred to any 

space [ANSI/ASHRAE 2016].

We found lead on hand wipe samples collected after participants washed their hands before 

leaving work. This indicated that soap and water alone did not sufficiently remove lead 

from the skin. NIOSH research shows that washing hands with soap and water alone is not 

completely effective in removing lead and other toxic metals from the skin [Esswein et al. 

2011; NIOSH 2014b,c]. Some commercially available lead removal products have been 

proven to remove more contamination from the skin. In addition, employees frequently 

reused gloves, which could potentially transfer contamination from the dirty gloves to the 

hands. Metals present on skin or clothing when leaving work could contaminate personal 

vehicles and homes and present a hazard to family members. 

With the exception of one personal air sample taken in the batteries and disassembly area 

that exceeded the REL for cadmium, personal exposures to other airborne metals were well 

below the lowest OELs. Overall, the highest concentrations of metals in personal samples 

were from participants working around the small shredder and optical sorter. In addition, area 
Health Hazard Evaluation Report 2015-0050-3308 Page 29

samples showed that concentrations of metals near the shredder, although very low, were 

slightly higher than levels in a sample taken in the disassembly area. The mechanical action 

of the small shredder coupled with the lack of local exhaust ventilation likely contributed to 

the higher concentrations of metals in the air. 

BLLs ranged from 0.99 μg/dL to 12 μg/dL. The NIOSH Adult Blood Lead Epidemiology 

and Surveillance System uses a surveillance case definition for an elevated BLL in adults 

of 5 μg/dL of blood or higher [CDC 2015a]. Three BLLs were over 5 μg/dL in shredding 

and sorting. These jobs have the highest potential for exposure to metals. Blood cadmium 

levels were well below the OSHA acceptable level of 5 μg/L. Two of the employees with the 

highest cadmium levels (0.5–1.0 μg/L) and two of the three employees with the highest BLLs 

smoked. Smoking can increase blood lead and blood cadmium levels [Adams and Newcomb 

2014; Mannino et al. 2005].

Although employees do not typically work near the metals sorter during production, the 

presence of low levels of mercury vapor indicate a potential for exposure in this and nearby 

areas during the recycling process even when not shredding florescent bulbs. These results 

indicate that mercury vapor could be emitted during the recycling process, particularly 

from components that contain fluorescent lights, batteries, medical and telecommunication 

equipment, and some flat-panel displays. No LCD mercury lamps were shredded at the 

company during our evaluation. While we cannot compare these area measurement results 

to OELs, employees are unlikely to exceed exposure limits on the basis of these area 

measurements and their typical work locations. 

The particulate monitors showed increases in particle concentrations when a fan was blowing 

across the sorting belt and when a bin of magnetic metals was replaced. These increases 

indicate that the magnetic metals sorting process generates particulates and that the fan is 

likely aerosolizing particulate matter, presumably metal scrap dust, and blowing it at the 

employee, increasing their potential for inhalation of metal dust. 

Increases in the number of particles less than 1 μm in size could be attributed to many 

particle-generating sources, including both natural and man-made particle sources. For 

instance, additional recycling operations were ongoing in the area and warehouse. In 

addition, forklifts, motors, pumps, and heaters were in operation; aluminum, plastic scrap, 

and dust were emptied in bins at adjacent areas; and the large garage doors to the warehouse 

were open. These activities and factors can create or introduce particles, including incidental 

nanoscale particulate matter, into the work environment.

We did not find indium in the nano-size range, and indium was not detected in the blood 

samples. Our area size-selective sampling results suggest that nano-sized indium, such as the 

indium nanoparticles commonly found in the LCD screens, are likely not being released from 

this shredding process. However, we found indium compounds in the larger and respirable 

size range cut point stages. We cannot rule out that indium nanoparticles could be present in 

agglomerated larger particles. At the time of our evaluation, employees were shredding LCD 

screens and other electronic devices that commonly contain indium and indium nanoparticle 

compounds. Measurement of various heavy metals such as titanium and manganese in the 

respirable and larger aerosol size ranges may be attributable to the shredding process, which 
Page 30 Health Hazard Evaluation Report 2015-0050-3308

may be releasing inhalable-sized aerosols. This is a potential inhalation hazard for employees 

working in the magnetic metals sorting area.

Our results showed migration of airborne metals from the processing area to the conference 

room. While we cannot determine the exact source of the metals in the air of the conference 

room, two pathways are likely. Because the general ventilation systems for both the 

processing areas and nonprocessing areas are shared and connected, air from the processing 

area could be recirculated to the conference room. In addition, passive air movement 

could carry some airborne metals from the processing area to the conference room through 

pathways such as the conference room door. Although airborne metal concentrations in the 

conference air samples were very low, employees are unnecessarily exposed in this area. A 

separate ventilation system for the conference room could reduce employee risk of exposures 

in this area. 

Flame Retardants

Hand Wipes and Dermal Exposure

Exposure to flame retardants in indoor non-work environments is thought to primarily occur 

from hand-to-mouth ingestion of dust and secondarily by absorption through the skin [Abdallah 

et al. 2015; Mäkinen et al. 2009]. These exposure pathways can also occur in workplaces. 

BDE-183 was not detected in any hand wipes and BDE-154 and BDE-153 were detected 

in a low percentage of the hand wipes. Because the use of these OctaBDE flame retardants 

in electronics was phased out after 2004, these results suggests that at the time of our 

evaluation, the company was not processing or processing very few electronics made before 

2004. We detected BDE-209, TPHP, TCP, BTBPE, DBDPE, and TBBPA in nearly all of the 

hand wipes. In addition, the amounts of these flame retardants on the hands increased across 

the work shift among participants working in processing, shipping, and office areas. This 

increase was not surprising because these flame retardants are currently used or have been 

recently used in electronics. Although shipping and receiving and office workers did not 

handle electronics as part of normal job duties, the shipping and receiving area was located 

within the sorting and shredding department, and some office employees regularly went into 

the processing areas. In addition, the air handling units for the office area pulled supply air 

from the processing areas. 

Office employees also had increases in TDCIPP, which is used mainly in polyurethane 

foam. Because polyurethane foam is used in so many types of products, its dust is found 

everywhere. The increase seen across the shift most likely represents office employees’ 

exposure from sitting in upholstered chairs that contain polyurethane foam. On the contrary, 

processing employees had much smaller median increases in TDCIPP levels on their hands 

across shifts. 

We detected some of the PentaBDE flame retardants (BDE-99 and BDE-47) and TDCIPP in 

most of the samples, and typically saw an increase from the preshift to the postshift levels. 

However for batteries and disassembly and the office, BDE-99 postshift medians are nearly 

equal to the preshift medians and BDE-47 postshift medians are lower than preshift medians. 
Health Hazard Evaluation Report 2015-0050-3308 Page 31

TDCIPP and PentaBDE are typically found in polyurethane foam, not in electronics [Alaee 

et al. 2003] and were phased out starting in 2005. However, several studies have shown that 

while PentaBDE and TDCIPP are not typically used in electronics, they are often present in 

high concentration in office dusts [Sjödin et al. 2008; Watkins et al. 2013], which could be 

pulled into electronic devices by their cooling fans. 

Thorough hand washing at the end of the work shift with soap and water should remove 

contaminants from the skin to reduce risk of possible ingestion through hand-to-mouth 

contact and continued dermal exposure. In addition, contaminants remaining on the skin 

could be transferred to non-work surfaces in vehicles and in the home. Table 14 shows the 

levels of selected flame retardants on hands of sorting and shredding, and batteries and 

disassembly participants compared to results published in studies of the general population, 

which were collected using similar hand-wipe methods. Hand wipes for several of the flame 

retardants (BDE-154, BDE-153, BDE-99, BDE-47, BDE-100) did not have substantial 

preshift and postshift differences nor were the levels substantially different than levels 

reported in one or more studies of the general population, suggesting minimal dermal 

exposures to these flame retardants at work. In contrast, the levels of BDE-209, TPHP, 

TCIPP, and TDCIPP among our participants were substantially higher than levels found 

the general population, even on preshift testing. These results illustrate not only workplace 

exposure, but also that these flame retardants were not completely removed from the skin 

between work shifts (and most likely after several hand washes) or that employees had 

dermal exposures outside of work, potentially from their vehicles and homes due to 

take-home exposure.
Page 32 Health Hazard Evaluation Report 2015-0050-3308

Table 14. Geometric mean and range of flame retardants on hand wipes in sorting and shredding participants, 

batteries and disassembly participants, and the general population, in ng/sample

Flame 

retardant

Sorting and shredding

n = 15–17

% Detected

GM

(range)

Batteries and disassembly

n = 17–18

% Detected

GM

(range)

General 

population*

n = 53

% Detected

GM

(range)

General 

population†

n = 33

% Detected

GM

(range)

General 

population‡

n = 40

% Detected

GM

(range) Preshift Postshift Preshift Postshift

OctaBDE (commonly used in electronics until around 2004)

BDE-183 0% 0% 0% 0% Not 

sampled

76%

0.7

(ND–8.5)

Not 

sampled

BDE-154 13%

(-)

(ND–24)

13%

(-)

(ND–58)

0% 11%

(-)

(ND–34)

87%

1.0

(ND–59.8)

97%

4.9

(ND–59)

Not 

sampled

BDE-153 6%

(-)

(ND–15)

35%

(-)

(ND–45)

6%

(-)

(ND–12)

17%

(-)

(ND–38)

91%

1.3

(ND–67.9)

97%

15.8

(ND–290)

Not 

sampled

OctaBDE and DecaBDE (commonly used in electronics until around 2013)

BDE-209 100%

315

(93–2,000)

100%

2,210

(470–11,000)

100%

311

(83–2,300)

100%

1,300

(180–7,800)

96%

19.5

(ND–804)

67%

43.1

(ND–270)

Not 

sampled

Commonly used in electronics now and in the past

TPHP 100%

297

(110–800)

100%

2,770

(500–11,000)

94%

170

(ND–800)

100%

770

(59–3,600)

87%

62.1

(ND–1,230)

Not 

sampled

100%

22.4

(?–416.7)

Less commonly used in electronics now and in the past

TCIPP 53%

(-)

(ND–1,500)

88%

849

(ND–4,600)

61%

(-)

(ND–850)

67%

(-)

(ND–560)

Not 

sampled

Not 

sampled

100%

45.4

(?–255)

Rarely used in electronics

PentaBDE

BDE-99 100%

44.8

(19–340)

100%

77.5

(26–160)

94%

55.6

(ND–230)

94%

50.9

(ND–370)

100%

26

(4.4–707)

100%

72.2

(0.9–747)

Not 

sampled

BDE-47 88%

31.6

(ND–230)

88%

46.8

(ND–120)

83%

35.3

(ND–190)

94%

30.3

(ND–170)

100%

18.4

(2.5–454)

97%

72.7

(ND–565)

Not 

sampled

BDE-100 18%

(-)

(ND–53)

47%

(-)

(ND–28)

56%

(-)

(ND–33)

28%

(-)

(ND–60)

81%

2.8

(ND–128)

100%

13.3

(0.08–142)

Not 

sampled

TDCIPP 94%

517

(ND–2,400)

100%

932

(170–5,300)

94%

548

(ND–3,600)

100%

754

(210–3,000)

91%

84.1

(ND–537)

Not 

sampled

95%

108.3

(ND–535)

? = Study did not provide a lower-end of the range

*Hoffman et al. 2015 

†Stapleton and Dodder 2008 

‡Hammel et al. 2016
Health Hazard Evaluation Report 2015-0050-3308 Page 33

Our results indicate that hand exposure to some flame retardants in this electronics recycling 

company differs greatly from exposures in the general population. TPHP hand exposures 

found in other electronic recycling facilities were similar to what we found [Mäkinen 

et al. 2009]. In our evaluation, TPHP was detected in 100% of the preshift and postshift 

hand wipes of the shredder and sorter employees. The TPHP level (GM = 2,766 ng) of our 

postshift hand wipe samples was approximately 45 times higher than the general population 

[Hoffman et al. 2015]. In addition, our hand wipe samples indicate that flame retardant 

exposures were higher for shredding and sorting participants than batteries and disassembly 

participants. Although employees had flame retardants on their hands before their work shift, 

increases in the levels of flame retardants during the work shift, particularly those commonly 

used on electronics, illustrate the potential for dermal exposure and highlight the importance 

of PPE and hand washing to reduce exposures. A study of flame retardant exposure in young 

children suggested those who washed their hands at least five times a day had lower levels 

of flame retardants on their hands than those who washed less often [Stapleton et al. 2014]. 

Office workers who washed their hands fewer than four times daily had significantly higher 

levels of PentaBDE on their hand wipes than those who washed four or more times daily 

[Watkins et al. 2011]. Absorption of TCIPP and TCEP was significantly reduced by hand 

washing in an experimental study using human ex vivo skin, but penetration continued, 

presumably from the reservoir in the skin [Abdallah et al. 2016]. Hand washing did not 

significantly reduce absorption of TDCIPP [Abdallah et al. 2016].

Several factors can affect overall interpretation of the hand wipe sampling results. The hand 

wipe sampling procedure removes an unknown proportion of the flame retardants that are 

present on the hand and can vary depending on the technique of the person doing the wiping. 

In our pilot hand wipe study the amount removed by the first gauze wipe set varied from 0% 

to 98% of the total. If a hand wipe removed more of a particular flame retardant preshift than 

was added to the hands during the shift, it could appear there was a decline in flame retardant 

levels, even though exposure to that flame retardant may have occurred during the work shift. 

The efficiency of hand wipes in collecting all the contamination that is present is unknown. 

Also, we do not know the efficiency of hand washing in removing different flame retardants. 

If hand washing was very efficient in removing flame retardants from the workers’ hands, 

then the postshift flame retardant levels might be far less than if hand washing had not been 

done. Participants with less time between their last hand washing and their postshift hand 

wipe sample might have lower amounts of flame retardants on their hands due to removal 

from washing. We instructed participants to wash their hands as they normally would during 

the work shift, but instructed them to refrain from washing them immediately before having 

their postshift hand wipe sampling done. We did not record the time interval from the last 

hand washing to the postshift wipe sampling. The wide variability of the results could be 

from interpersonal sampling variation, such as participants wiping their hands differently, 

thereby removing the flame retardants from a previously unwiped portion of the hand or 

differences in applied pressure and speed of wiping. We do not know if differences in skin 

moisture and use of skin care products could affect the results.
Page 34 Health Hazard Evaluation Report 2015-0050-3308

Personal Air Sampling for Flame Retardants

Several published studies have examined airborne exposure to flame retardants in homes and 

nonindustrial settings. Allen et al. [2007] collected inhalable personal air samples for PBDEs 

from 20 individuals in Boston for 7 days while they were at home. The main congeners 

they detected were BDE-47, BDE-209, and BDE-99. BDE-47 was detected in 100% of the 

air samples with a GM concentration of 0.227 ng/m3. BDE-209 was detected in 45% of the 

samples with a GM concentration of 0.174 ng/m3. The authors estimated that about 22% of 

the participants’ total BDE-209 exposures were likely through inhalation.

LaGuardia and Hale [2015] evaluated flame retardant exposures on four individuals in 

their homes in Seattle. Samples were collected for an 8-hour period. Inhalable personal 

air sampling found that the predominant flame retardants were TDCIPP (94% of the 

total) and TCIPP (65% of the total). BDE-209 was detected in two of the four samples, at 

concentrations of 0.1 ng/m3 and 3.8 ng/m3. Schreder et al. [2016] collected personal air 

samples for chlorinated organophosphate flame retardants over a 24-hour period, on 

10 individuals in Washington. The median concentrations were 262 ng/m3 (TCIPP), 82 ng/m3

(TDCIPP) and 78 ng/m3 (TCEP). 

Swedish researchers examined the presence and levels of several organophosphate flame 

retardants using area air sampling for particulate and vapor at night in three schools, a 

day care center, and an office. TPHP was detected in all locations, but below levels of 

quantification in two, and at concentrations less than 1 ng/m3 in the others [Carlsson et al. 

1997]. The highest concentrations these researchers measured were for TCEP, with mean 

concentration in each building ranging from 11 ng/m3 to 250 ng/m3. These researchers also 

detected TCIPP in much lower concentrations (maximum mean concentration 41 ng/m3).

We anticipated that occupational exposures to flame retardants in the air would differ from 

air sampling results in non-industrial environments. Our evaluation demonstrated airborne 

exposures to several flame retardants, primarily BDE-209, TPHP, TCP, and DBDPE. We 

detected BDE-209 in 100% of our air samples at a GM concentration of 189 ng/m3 (range: 

29–3,576 ng/m3). This was far higher than the levels found in non-industrial settings [Allen 

et al. 2007; LaGuardia and Hale 2015]. In addition, the airborne BDE-209 concentrations 

we measured were well above the GM concentration of 25 ng/m3 in personal air samples 

collected over 2 years reported in Swedish electronics recycling disassemblers [PetterssonJulander et al. 2004] and concentrations of 0.22 ng/m3

 found in general air samples in a 

Swedish electronics recycling company [Sjodin et al. 2001]. 

A study of sorters and disassemblers (not shredders) at two electronics recycling facilities in 

Finland documented median airborne DBDPE concentrations of 61 ng/m3 and median sum 

PBDE concentrations of 295 ng/m3 [Rosenberg et al. 2011]. The researchers recommended 

ventilation controls then resampled after their installation. Median airborne DBDPE 

concentrations decreased to 14 ng/m3, and median PBDE concentrations dropped to 

65 ng/m3, indicating that controls reduced exposures. Our DBDPE results in the sorting and 

shredding department (median = 145 ng/m3) was higher and our result in the batteries and 

disassembly (median = 42.9 ng/m3) was slightly lower than the initial airborne concentrations 
Health Hazard Evaluation Report 2015-0050-3308 Page 35

reported by Rosenberg et al. [2011]; however, we cannot directly compare our PDBE results 

with Rosenberg et al. [2011] because that study did not differentiate congeners. 

TPHP has been used as a flame retardant in electronic products as well as a plasticizer [van 

der Veen and Boer 2012]. We found TPHP in the second highest concentration in our air 

samples, with a GM concentration of 95 ng/m3 in our disassembly and battery participants 

and 287 ng/m3 among shredding and sorting participants. Only 75% of the air samples 

from the office participants were detectable, with a maximum concentration of 50 ng/m3.A 

study of two other electronics recycling facilities in Finland where sorting, dismantling, and 

crushing were performed showed TPHP was present in the highest airborne concentrations 

of the eight organophosphate flame retardants measured (GM personal air concentrations of 

TPHP of 760 ng/m3 and 850 ng/m3) [Mäkinen et al. 2009]. 

Mäkinen et al. [2009] also found that airborne TCP was typical in electronics dismantling 

facilities. The GM personal air TCP concentration in a dismantling and sorting room of an 

electronics dismantling company was 90 ng/m3 (range: 62 ng/m3 to 175 ng/m3) and 

110 ng/m3 (range: 62 ng/m3 to 175 ng/m3) in an electronics crushing process at a separate 

facility. Comparatively, our disassembly and battery sorting participants had a GM exposure 

of 65.8 ng/m3, while our shredding and sorting participants had a GM exposure of 251 ng/m3. 

Mäkinen et al. [2009] detected TBBPA in few air samples and at very low concentrations. 

Sjodin et al. [2001] found TBBPA present in air with a mean concentration of 0.20 ng/m3, 

and Rosenberg et al. [2011] found TBBPA with a median concentration of 145 ng/m3. We 

only detected TBBPA in the air in 17% of samples, with a median concentration of ND. 

TBBPA is one of the most commonly used brominated flame retardants in printed circuit 

boards. Unlike most of the flame retardants we examined, which are additive flame retardants 

(blended with the plastics), TBBPA is a reactive flame retardant (chemically bonded into the 

plastics). Because of this chemical bonding, we found very little in our air samples, as 

expected [Rosenberg et al. 2011]. It is unclear why TBBPA was detected in higher 

concentrations in previous studies.

BTBPE is found in Firemaster 680, which is used in many computer housings. PetterssonJulander et al. [2004] found a GM concentration of airborne BTBPE of 15 ng/m3

. We 

measured similar but slightly lower GM concentrations among sorters and shredders 

(14.2 ng/m3) and batteries and disassemblers (7.43 ng/m3). 

TCIPP, TDCIPP, TCEP, and PentaBDE are not typically used in electronics and are 

predominantly found in polyurethane foam [Alaee et al. 2003; Stapleton et al. 2011; van der 

Veen and Boer 2012]. We detected no TCIPP, TDCIPP, or TCEP, and we detected low 

concentrations of PentaBDE with the highest GM concentration of 13.3 ng/m3, as represented 

by its primary congener BDE-99. On the contrary, the studies from non-industrial settings 

[LaGuardia and Hale 2015; Schreder et al. 2016] detected higher concentrations of TCIPP 

and TDCIPP. We suspect the source of PentaBDE to be primarily from dust collected inside 

of the electronic equipment. 

These data indicate that airborne exposure in this electronics recycling company differ 

greatly from those in homes and nonindustrial settings, but are within the range of exposures 
Page 36 Health Hazard Evaluation Report 2015-0050-3308

found in other electronic recycling facilities. In addition, our air samples indicate that 

flame retardant exposures were higher for shredding and sorting participants than batteries 

and disassembly participants. This is likely due to the mechanical grinding that occurs in 

shredding and sorting as opposed to the more manual tasks in batteries and disassembly.

Biological Burden of Flame Retardants: Blood

We examined serum PBDE concentrations and compared them to a representative sample 

of the general population. The GM serum concentration of BDE-209 (the flame retardant 

present in the highest concentrations in the air and with large increases on hands across 

shifts) was 8.098 ng/g lipid weight. NHANES data did not have reported values because 

so many of their samples were below the LOD of 5.8 ng/g lipid weight. The higher serum 

BDE-209 concentrations in our participants appears to be from occupational exposures and 

not from diet. The NHANES samples were collected in 2007 and 2008, when concentrations 

were presumably higher because this was prior to the phase-out of DecaBDE. Data is also 

now available for the years 2009 and 2010, but it is segregated by age groups, gender, and 

race/ethnicity [CDC 2018]. Swedish electronics disassembly employees had a median serum 

BDE-209 concentration of 4.8 ng/g lipid weight [Thuresson et al. 2006a]. Workers were 

retested several years later after the shredder was moved from the disassembly area to a 

different location. The median decrease in their serum BDE-209 concentrations was 46% 

[Thuresson et al. 2006b]. In the initial Swedish study, serum concentrations of 

BDE-47, BDE-153, BDE-154, and BDE-183 were also significantly higher than their 

reference populations of computer clerks and hospital cleaners [Sjodin et al. 1999]. 

We found median serum concentrations of BDE-153 about double that of the general 

population sample, but the concentrations of others were similar to the general population. 

Concentrations of other PBDEs, PCBs, and other persistent pollutants were generally lower 

in our participants than in NHANES participants. This may be because the NHANES 

specimens were collected several years before ours when concentrations were likely 

higher, but it does suggest that diet was not the primary contributor to the serum BDE-209 

concentrations in our participants. In addition, PCB-153 concentrations in our participants 

was lower than in the NHANES specimens. PCB-153 is a stable, persistent contaminant, and 

exposure to it comes mainly from food [Jakobsson et al. 2002].

Biological Burden of Flame Retardants: Urine

Biomonitoring for phosphate flame retardants is in its early phase [Dodson et al. 2014; 

Kosarac et al. 2016] and identification of major metabolites and pharmacokinetics are not 

fully elucidated [Dodson et al. 2014; Kosarac et al. 2016]. However, half-lives of identified 

flame retardant metabolites appear to be relatively short (hours); therefore, results of urine 

measurements likely reflect recent exposures [Carignan et al. 2016; Dodson et al. 2014; 

Hammel et al. 2016; Meeker et al. 2013a]. NHANES has recently released urinary metabolite 

data for the general population for the years 2013 and 2014 [CDC 2018].

Median urinary concentrations of DPHP (a metabolite of TPHP, used in plastic housings of 

electronics, among other things) approximately doubled across the shift in participants who 

performed sorting and shredding during our visit, stayed about the same in participants who 
Health Hazard Evaluation Report 2015-0050-3308 Page 37

performed disassembly of electronic items and battery sorting, and declined in participants 

who performed mainly office work. This was true whether looking at creatinine corrected or 

uncorrected values. Table 15 contains results of urine testing for flame retardant metabolites 

from published studies in the general population. GM uncorrected postshift concentrations 

(3.1 μg/L) among sorters and shredders were higher than those reported in the U.S. general 

population, which ranged from 1.1 μg/L to 1.9 μg/L.

Table 15. Uncorrected concentrations of urine flame retardant metabolites in the general 

population, in μg/L

Flame 

retardant

General population

% detected 

GM 

range

N = 9* N = 39† N = 16‡ N = 13§ N = 40¶

Commonly used in electronics now and in the past

DPHP 

(parent 

compound 

TPHP)

100%

1.074

0.29–7.44

97% 

1.9

ND (< 0.005)–37.3

62% 

1.1 (mean)

ND (< 0.23)–6.8

100%

1.5

0.2–5.6

100%

1.14

**–26.77

Less commonly used in electronics now and in the past

BCIPP 

(parent 

compound 

TCIPP)

Not sampled Not sampled 31%

0.17 (mean)

ND (< 0.06)–0.97

92%

0.4

0.04–3.5

18%

Not calculated

**–0.57

BCEP 

(parent 

compound 

TCEP)

Not sampled Not sampled 75% 

0.76 (mean)

ND (< 0.10)–2.1

100%

3.4

0.4–15.0

Not sampled

Rarely used in electronics

BDCIPP 

(parent 

compound 

TDCIPP)

100%

0.148

0.05–1.66

97% 

1.3

ND (< 0.013)–19.9

94% 

0.46 (mean)

ND (< 0.02)–3.9

100%

2.5

0.5–7.3

100%

2.32

**–21.21

*Cooper et al. 2011

†Hoffman et al. 2014 

‡Dodson et al. 2014

§Petropoulou et al. 2016

¶Hammel et al. 2016

**Limit of detection not given
Page 38 Health Hazard Evaluation Report 2015-0050-3308

Urinary BDCIPP (a metabolite of TDCIPP, whose main use is in polyurethane foam) 

concentrations either remained about the same or declined across the shift in our participants, 

despite relatively high hand levels of TDCIPP. The overall GM uncorrected concentrations 

preshift were 2.43 μg/L and 1.94 μg/L postshift. They were slightly higher than those 

reported in the U.S. general population, which ranged from 1.3–2.5 μg/L (Table 15). BDCIPP 

is specific to TDCIPP. No TDCIPP was detected in the air in this evaluation. TDCIPP in 

dust has been detected at higher levels in vehicles and offices than in homes [Carignan et 

al. 2013]. Office participants had a large increase in median hand levels of TDCIPP across 

the shifts, yet GM and median urine concentrations of BDCIPP either remained similar 

(creatinine corrected) or decreased (uncorrected). This was unexpected considering that 

animal studies show absorption through the skin and gastrointestinal tract [Nomier et al. 

1981]. The half-life of TDCIPP in rats is between 1.5 and 5.4 hours [Nomier et al. 1981], so 

perhaps urine concentrations of BDCIPP peaked sometime between the end of the shift and 

the beginning of the next shift because of hand exposure continuing through until the end of 

the shift.

Urinary BCIPP and BCEP concentrations in our participants were lower than or similar 

to what has been found in the general population. Urinary TBBA was not detected in any 

of our samples. One study of 52 U.S. adults reported a GM concentration of 0.0056 μg/L. 

Because our LOD was 0.05 μg/L, we may have been unable to detect it [Hoffman et al. 

A study of gymnasts before and after a 2.5 hour practice demonstrated that GM DPHP 

concentrations nearly doubled (from 6 to 11 μg/L), and then began to decline between 1 and 

3 hours after practice [Carignan et al. 2016]. In addition to its use in electronics products, 

TPHP is a component of Firemaster 550 (and other flame retardant mixtures), which is used 

in polyurethane foam. Gymnasts use pits filled with foam blocks and other foam padded 

equipment to protect them from injury when falling. These levels in gymnasts were much 

higher than those we found (GM range: ND [< 0.16]–9.17 μg/L). 

A study of the relationship between reproductive outcomes in 33 men found a 57% decrease 

in sperm concentration, a 19% decrease in straight line velocity, a 13% decrease in linearity, 

and a 38% decrease in inhibin B concentrations in blood for each interquartile increase in 

urinary DPHP [Meeker et al. 2013a]. Specific gravity corrected urinary DPHP ranged from 

nondetectable (< 0.06 μg/L) to 9.84 (median 0.27 μg/L, 95th percentile 2.65 μg/L) in the 

study from which these men were a subset [Meeker et al. 2013b]. Another study found a 

significant 0.43 μg/dL increase in mean total T4 serum concentrations in individuals with 

specific gravity corrected urine DPHP concentrations greater than or equal to 2.65 μg/L 

compared to those with concentrations below 2.65 μg/L [Preston et al. 2017]. 

TPHP was present in the air in our electronics recycling company in the second highest 

concentrations, after BDE-209. Median airborne concentrations of TPHP were highest among 

sorting and shredding participants. All groups of participants had increased median levels of 

TPHP on their hands postshift, but the difference between the preshift and postshift median 

levels were highest in sorting and shredding participants. These findings in conjunction with 

the urinary DPHP findings indicate that exposure to TPHP among shredding and sorting 

participants during the work shift exceeds background. 
Health Hazard Evaluation Report 2015-0050-3308 Page 39

2014]. Urinary DoCP and DpCP (metabolites of TCP, which is also used in plastic housings 

of electronics) were mostly undetectable, despite TCP being present in the third highest GM 

and median airborne concentrations, after BDE-209 and TPHP. GM and median hand wipe 

levels of TCP also increased from the preshift to postshift levels for all participants, with the 

biggest differences and highest concentrations among shipping and receiving, and sorting 

and shredding. The absence of urinary metabolites could be due to a variety of reasons. Urine 

may not be an important route of excretion for TCP in humans. Kurebayashi et al. [1985] 

found that TCP was excreted mainly in the feces (77%) and not the urine (12%) of rats after a 

single oral dose. In addition, dermal or inhalation absorption may be poor.

Biological Burden of Flame Retardants: Uncertainty Regarding 

Health Effects

Recognition of the potential adverse effects of exposure to flame retardants is relatively 

recent, unlike lead, whose effects have been recognized and studied for decades, allowing us 

to predict health effects based upon the BLL. Some human epidemiologic studies have shown 

an association between exposure to certain flame retardants and changes in male reproductive 

hormones, semen quality, thyroid homeostasis, and hormone levels and fertility in women; 

cryptorchidism (undescended testicles); low birth weight and length; delayed motor skills; 

decreased IQ; and cancer [Abdallah et al. 2015; Czerska et al. 2013; Dallaire et al. 2009; 

Dishaw et al. 2014; Grant et al. 2013; Johnson et al. 2013; Meeker and Stapleton 2010; 

Meeker et al. 2013a,b; van der Veen and de Boer 2012]. However, it is not clear at what 

levels these effects begin to occur. Studies like this one help us identify populations who have 

the highest exposure and begin to study health effects in them and will ultimately lead to our 

ability to predict health effects based upon biological burden. 

Conclusions

Employees at this electronics recycling company are exposed to metals, including lead 

and cadmium. One employee in the batteries and disassembly area had an overexposure to 

cadmium. Three employees working in shredding and sorting had elevated BLLs. There 

is the potential for take-home contamination with lead and other metals. These metals are 

hazardous, even at low levels. Employees are also exposed to several flame retardants 

through inhalation and skin contact, especially BDE-209, TPHP, TCP, and DBDPE. The GM 

serum concentration of BDE-209 was higher than that found in the general population. The 

median DPHP (a metabolite of TPHP) levels in the urine of participants who worked in the 

shredding and sorting area doubled from preshift to postshift, and postshift DPHP levels were 

higher than levels in the general population. We are not able to predict specific health effects 

based on the levels of flame retardants in employees’ blood and urine. However, we believe 

that uptake of flame retardants in the body is potentially hazardous to health. Exposures need 

to be reduced. There is the potential for take-home contamination with cadmium, lead, other 

metals, and flame retardants.
Page 40 Health Hazard Evaluation Report 2015-0050-3308

Recommendations

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

electronics recycling company to use a labor-management health and safety committee or 

working group to discuss our recommendations and develop an action plan. Those involved 

in the work can best set priorities and assess the feasibility of our recommendations for the 

specific situation at the electronics recycling company. 

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

C). This approach groups actions by their likely effectiveness in reducing or removing hazards. 

In most cases, the preferred approach is to eliminate hazardous materials or processes and 

install engineering controls to reduce exposure or shield employees. Until such controls are in 

place, or if they are not effective or feasible, administrative measures and PPE may be needed.

Engineering Controls

Engineering controls reduce employees’ exposures by removing the hazard from the process or by 

placing a barrier between the hazard and the employee. Engineering controls protect employees 

effectively without placing primary responsibility of implementation on the employee. 

1. Discontinue the use of pedestal fans, and consider adding supplemental ventilation for 

cooling in the warehouse to reduce the amount of re-aerosolization and distribution of 

metal-containing dusts.

2. Relocate conference and office area air intakes, so that air is brought into these spaces 

from outdoors rather than from the warehouse. The office and break room should be 

kept under positive pressure relative to the warehouse, meaning that air flows from the 

office and break room into the warehouse. In addition, adequate outdoor air should be 

introduced into the office space, and air from the warehouse should not be entrained 

into the office air [ANSI/ASHRAE 2016].

3. Install local exhaust ventilation on the small shredder and optical sorter.

Administrative Controls 

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

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

commitment and employee acceptance. Regular monitoring and reinforcement are necessary 

to ensure that policies and procedures are followed consistently.

1. Include all employees in a lead exposure prevention program. Follow the medical 

surveillance program outlined in Appendix C in addition to all requirements of the 

OSHA lead standard. Provide employees with the results of their individual BLLs in 

writing after each blood draw.

2. Provide employees with a lead-removing product to wash their hands when they 

leave the processing area, and before eating, drinking, or smoking. Learn more about 

commercially available lead removal products by reading “Information for Workers, 
Health Hazard Evaluation Report 2015-0050-3308 Page 41

How You Can Keep Yourself and Your Family Safe from Lead” available at 

http://www.cdc.gov/niosh/topics/lead/safe.html.

3. Prohibit dry sweeping. Use wet cleaning methods or high-efficiency particulate air 

vacuuming instead.

4. Complete a job hazard assessment (or job hazard analysis) according to the OSHA

PPE standard (29 CFR 1910.132) for tasks throughout the processing areas to 

standardize work practices and determine what PPE will be required for each task. You 

can find additional information on job hazard analysis at 

http://www.osha.gov/Publications/osha3071.pdf. 

5. Do not permit eating or drinking outside of the breakroom.

6. Provide laundry facilities on-site or contract a laundry service to ensure that 

contaminated uniforms are not taken home. Laundry personnel should be made aware 

of the potential exposure to lead and other contaminants on work clothes and take 

action to minimize potential exposures. 

7. Install an employee shower and clean clothes changing room. Separate these areas 

from the storage room. Design the changing room and shower area so that once 

employees shower, they cannot re-enter the potentially contaminated changing 

area. Clean items should be stored in changing rooms separate from areas where 

contaminated work items are stored.

Personal Protective Equipment

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

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

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

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

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

effective engineering and administrative controls are in place.

1. Provide clean gloves for daily use, or use clean inner gloves when reusing dirty 

cloth, leather, or cut-resistant gloves. Instruct employees to leave dirty gloves in 

the work area. Encourage employees to replace dirty gloves frequently to minimize 

contamination of surfaces with metals.

2. Require employees who voluntarily use disposable filtering facepiece respirators to 

wear them properly. Guidelines for putting on and taking off a disposable respirator 

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

3. Require respirators for employees who work in the disassembly and shredder areas 

until overexposures to cadmium are controlled. 

4. Follow the OSHA respiratory protection standard for general industry 

[29 CFR 1910.134] for a comprehensive respiratory protection program. Information 

from NIOSH can also help in developing an effective respirator program. See 

http://www.cdc.gov/niosh/topics/respirators/. A written program should include the 
Page 42 Health Hazard Evaluation Report 2015-0050-3308

following elements:

○ written operation procedures

○ appropriate respirator selection

○ employee training

○ effective cleaning of respirators

○ proper storage

○ routine inspection and repair

○ exposure surveillance

○ program review

○ medical approval

○ use of approved respirators

5. Ensure all aspects of the OSHA respiratory protection standard are correctly 

implemented. These include the following:

○ ensuring that employees are clean shaven when wearing respirators

○ using appropriate fit testing procedures for selected respirators

○ wearing respirators all the time while in work areas of required respirator use

○ developing a formal respirator cartridge change-out schedule to determine if 

current change-out practices are sufficient
Health Hazard Evaluation Report 2015-0050-3308 Page 43

Appendix A: Tables

Table A1. Flame retardants sampled during this evaluation and where they are typically found

Flame retardant CAS number Typically found in

Commonly used in electronics until around 2004

Octabromodiphenyl ether 

technical mixture (OctaBDE)

32536-52-0 Acrylonitrile-butadiene-styrene resins and housings for 

electrical equipment; not used in United States since 2004

Commonly used in electronics until around 2013

Decabromodiphenyl ether 

technical mixture (DecaBDE)

1163-19-5 High impact polystyrene for television and computer monitor 

housings, polycarbonate and polymer resins, rubber; 

not used in United States since 2013

Commonly used in electronics now and in the past

Tris(phenyl) phosphate

(TPHP)

115-86-6 High impact polystyrene and acrylonitrile-butadiene-styrene 

plastics for electronics housings, printed wiring boards, 

synthetic resins and decorative laminated sheets, 

photographic film, plasticizer in lacquers, varnishes, and 

hot melt adhesives, in roofing paper, component of 

Firemaster 550 (used as a PentaBDE replacement in foam)

Tricresyl phosphate (TCP) 1330-78-5 Polystyrene and plastics for housings, rubbers, cables, 

hoses, conveyor belts, waterproofing

Decabromodiphenyl ethane

(DBDPE)

84852-53-9 Used as a replacement for DecaBDE) in high impact 

polystyrene and acrylonitrile-butadiene-styrene plastics for 

electronics housings, wires and cables, and textiles

1,2-Bis(2,4,6-

tribromophenoxy)ethane

(BTBPE)

37853-59-1 Firemaster 680 (a replacement for OctaBDE) in high impact 

polystyrene and acrylonitrile-butadiene-styrene plastics for 

electronics housings, thermoplastics, elastomers, adhesives 

and coatings

Tetrabromobisphenol-A

(TBBPA)

79-94-7 Printed circuit boards, epoxies, and polycarbonate resins

Less commonly used in electronics now and in the past

2-ethylhexyl 2,3,4,5-

tetrabromobenzoate

(EH-TBB)

183658-27-7 Firemaster 550 (used as a replacement for PentaBDE in 

foam), polyvinyl chloride and neoprene, wire and 

cable insulation, coated fabrics

Bis(2-ethylhexyl) 

tetrabromophthalate

(BEH-TEBP)

26040-51-7 Firemaster 550 (used as a replacement for PentaBDE in 

foam), also for flexible polyvinyl chloride, wire and 

cable insulation, film and sheeting, coated fabrics, 

wall coverings, and adhesives

Tris(chloroethyl) phosphate

(TCEP) 

115-96-8 Polyester resins, adhesives, and coatings

Tris(2-chloroisopropyl) 

phosphate (TCIPP)

13674-84-5 Polyurethane rigid and flexible foam, polyvinyl chloride, and 

epoxy resin, thermosets and thermoplastics, textile finishes

α-, β-, γ 

Hexabromocyclododecane

(α-, β-, γ HBCD)

134237-50-6

134237-51-7 

134237-52-8

Polystyrene for building construction, high impact 

polystyrene for electronics casings, acrylic and 

latex dispersions (textile backings)

Rarely used in electronics

Pentabromodiphenyl ether 

technical mixture (PentaBDE)

32534-81-9 Polyurethane foam and textiles, so often present in dusts; 

not used in United States since 2004

Tris(1,3-dichloro-2-propyl) 

phosphate (TDCIPP)

13674-87-8 Polyurethane foam

CAS = Chemical abstract service
Page 44 Health Hazard Evaluation Report 2015-0050-3308

Table A2. Major congeners of PentaBDE, OctaBDE, and 

DecaBDE [La Guardia et al. 2006; Alaee et al. 2003]

Flame retardant and 

major congeners

CAS Number Percentage

PentaBDE technical mixture 32534-81-9

BDE-99* 60348-60-9 45–49

BDE-47* 5436-43-1 38–42

BDE-100 189084-64-8 7.5–13

BDE-153† 68631-49-2 5.3–4.0

BDE-154† 207122-15-4 2.7–4.5

BDE-85 182346-21-0 2.2–3.0

OctaBDE technical mixture 32536-52-0

BDE-183* 207122-16-5 13–42

BDE-209‡ 145538-75-5 1.3–50

DecaBDE technical mixture 1163-19-5

BDE-209 145538-75-5 97–98

BDE-206§ 63387-28-0 low

*These congeners are used as markers for their parent 

chemicals.

†These can also be components of OctaBDE.

‡Photolytic debromination of BDE-209 can form BDE-183 

[Stapleton and Dodder 2008].

§This is also a breakdown product of BDE-209.
Health Hazard Evaluation Report 2015-0050-3308 Page 45

Table A3. Results of personal air samples for metals (in μg/m3) collected over three days for 

15 employees (n = 45)

Metal Median GM (range) Lowest OEL Agency

Aluminum 14 11.9 (1.5–87) 10,000 NIOSH

Antimony 0.021 0.0600 (0.020–1.9) 500 OSHA/NIOSH/ACGIH

Barium 2.5 3.10 (0.36–27) 400 OSHA/NIOSH/ACGIH

Beryllium 0.010 0.0100 (0.010–0.020) 0.05 ACGIH

Cadmium 0.082 0.0890 (0.01–6.4)* 5 OSHA

Chromium 0.15 0.238 (0.15–1.2) 500 NIOSH/ACGIH

Cobalt 0.30 0.401(0.30–2.0) 20 ACGIH

Copper 2.2 2.55 (0.23–23) 1,000 NIOSH/OSHA/ACGIH

Indium 0.22 0.254 (0.22–2.5) 100 NIOSH/ACGIH

Iron 37 36.4 (4.0–550) 5,000 N/A

Lead 1.7 1.91 (0.060–19) 50 OSHA/NIOSH/ACGIH

Manganese 1.03 1.53 (0.13–45) 100 ACGIH

Neodymium 0.20 0.254 (0.06–3.5) 100 N/A

Nickel 0.52 0.596 (0.06–5.4) 15 NIOSH

Potassium 2.6 2.63 (0.79–14) 2,000 N/A

Silver 0.13 0.163 (0.01–1.8) 10 OSHA/NIOSH

Tin 1.4 1.87 (0.01–17) 2,000 OSHA/NIOSH/ACGIH

Yttrium 1.4 1.35 (0.2–16) 1,000 OSHA/NIOSH/ACGIH

Zinc 9.7 10.8 (1.1–220) 5,000 NIOSH

ACGIH = American Conference of Governmental Industrial Hygienists

N/A = not applicable

*One employee, working in batteries and disassembly, was overexposed to cadmium.
Page 46 Health Hazard Evaluation Report 2015-0050-3308

Table A4a. Size-selective area air samples results for metals, in μg/m3

Cut point (μm) Location Beryllium Cadmium Indium Lead Manganese

0.25 Office ND ND ND ND [0.0042]

0.44 ND ND ND ND [0.0058]

0.77 ND [0.0033] ND 0.085 0.042

1.4 ND [0.0017] ND 0.054 0.019

2.5 ND [0.0012] ND 2.0 [0.0065]

10 ND ND ND ND 0.0096

0.25 Processing ND 0.10 0.39 3.7 9.8

0.44 ND 0.024 0.13 0.94 2.0

0.77 ND 0.017 0.14 0.86 1.1

1.4 ND [0.0039] ND 0.18 0.18

2.5 ND ND ND 0.067 0.067

10 ND ND ND ND 0.014

ND = not detected above the MDC (not shown)

Note: total run time and sample volume was 260 minutes and 26,000 liters for the background 

sample and 255 minutes and 25,500 liters for the processing sample.

[ ] = Concentrations in brackets are between the minimum detectable and minimum quantifiable 

concentration (not shown). This means there is more uncertainty associated with this value.

Table A4b. Size-selective area air samples results for metals, in μg/m3 (continued)

Cut point (μm) Location Neodymium Nickel Silver Tin Titanium

0.25 Office ND ND ND ND [0.0014]

0.44 ND [0.0042] ND ND [0.0013]

0.77 ND 0.014 0.0054 0.039 0.012

1.4 ND [0.0085] [0.0028] 0.019 0.0077

2.5 ND [0.0088] ND ND 0.0050

10 ND [0.0058] [0.0021] ND 0.0018

0.25 Processing 0.94 1.5 0.47 3.1 0.98

0.44 0.16 0.28 0.075 0.82 0.22

0.77 0.13 0.18 0.047 0.67 0.21

1.4 0.027 0.030 0.0082 0.12 0.038

2.5 ND [0.012] [0.0033] 0.05 0.015

10 ND ND ND ND 0.0030

ND = not detected above the MDC (not shown)

Note: total run time and sample volume was 260 minutes and 26,000 liters for the background 

sample and 255 minutes and 25,500 liters for the processing sample.

[ ] = Concentrations in brackets are between the minimum detectable and minimum quantifiable 

concentration (not shown). This means there is more uncertainty associated with this value.
Health Hazard Evaluation Report 2015-0050-3308 Page 47

Table A6. Comparing selected PCBs found in the blood of electronics recycling employees with the 

National Health and Nutrition Examination Survey for the general population, in ng/g lipid weight

Polychlorinated 

biphenyl

Electronics recycling company 

participants

(n = 11)

National Health and 

Nutrition Examination Survey 

(2003–2004)

Median GM Maximum Median GM 95th 

percentile

Polychlorinated 

biphenyl 28

14.7 12.3 19.7 4.98 4.88 11.1

Polychlorinated 

biphenyl 66

3.41 2.76 4.99 1.40 1.42 4.20

Polychlorinated 

biphenyl 74

3.21 2.87 6.47 5.00 5.38 24.1

Polychlorinated 

biphenyl 99

2.40 2.44 10.4 4.08 4.52 18.6

Polychlorinated 

biphenyl 153

10.6 10.2 62.1 24.2 23.7 101

Polychlorinated 

biphenyl 156

0.994 1.18 10.9 4.10 3.31 16.8

Polychlorinated 

biphenyl 170

1.99 2.19 20.0 7.83 6.86 29.5

Polychlorinated 

biphenyl 180

4.81 5.18 44.9 21.5 19.0 88.0

Polychlorinated 

biphenyl 187 

2.49 2.67 17.3 5.71 5.20 25.9

Table A5. Comparing selected PPs found in the blood of electronics recycling employees with the 

National Health and Nutrition Examination Survey for the general population, in ng/g lipid weight

Persistent pesticide Electronics recycling 

company participants

(n = 11)

National Health and 

Nutrition Examination Survey 

(2003–2004)

Median GM Maximum Median GM 95th 

percentile

Polybrominated 

biphenyl 153

0.892 1.05 6.55 2.50 2.72 34.6

Hexachlorobenzene 7.92 8.52 16.8 15.1 15.5 29.0

Betahexachlorocyclohexane1.81 1.85 3.91 ND 7.89 62.2

Oxychlordane 3.09 3.43 19.6 11.4 10.6 39.2

Trans-nonchlor 5.06 6.65 31.5 17.3 16.9 74.7

p,p’-dichlorodiphenyl

trichloroethene

82.5 76.1 211 233 268 1,990

o,p’-dichlorodiphenyl

trichloroethane

1.73 1.71 4.77 Not 

reported

ND ND

p,p’-dichlorodiphenyl

trichloroethane

1.91 2.22 7.74 Not 

reported

ND 20.7
Page 48 Health Hazard Evaluation Report 2015-0050-3308

Table A7. Uncorrected concentrations or flame retardant metabolites in urine of electronics recycling 

employees and in the National Health and Nutrition Examination Survey, in μg/L. Samples are the third 

day of sampling, post-shift values.

Electronics recycling company 

participants (n = 14)

National Health and 

Nutrition Examination Survey*

Median GM† Max Median GM 95th 

percentile

Commonly used in electronics now and in the past

DPHP (TPHP)

LOD = 0.16

1.6 1.8 7.1 0.73 0.76 5.5

DpCP (TCP)

LOD = 0.05 

ND ND 0.21 ND Not 

calculated

0.10

DoCP (TCP)‡

LOD = 0.05

ND ND ND ND ND ND

Less commonly used in electronics now and in the past

TBBA (EH-TBB)

LOD = 0.05

ND ND ND ND ND ND

BCEP (TCEP)

LOD = 0.08

0.57 0.54 1.5 0.37 0.39 3.6

BCIPP (TCIPP)

LOD = 0.10

ND ND 0.84 0.16 0.19 1.3

Rarely used in electronics

BDCIPP (TDCIPP)

LOD = 0.11

1.9 2.1 11 0.85 0.82 6.4

*Age 20 to 59, n = 1266, samples taken 2013 and 2014

†GM not calculated if proportion of results below the limit of detection was too high to provide a valid result.

‡n = 13 for this compound 

Table A8. Creatinine corrected concentrations or flame retardant metabolites in urine of electronics 

recycling employees and in the National Health and Nutrition Examination Survey, in μg/g creatinine. 

Samples are the third day of sampling, post-shift values 

Electronics recycling company 

participants (n = 14) 

National Health and 

Nutrition Examination Survey*

Median GM† Max Median GM 95th 

percentile

Commonly used in electronics now and in the past

DPHP (TPHP) 1.3 1.1 3.1 0.70 0.79 4.7

DpCP (TCP) ND ND 0.09 ND Not 

calculated

0.18

DoCP (TCP)‡ ND ND ND ND ND ND

Less commonly used in electronics now and in the past

TBBA (EH-TBB) ND ND ND ND ND ND

BCEP (TCEP) 0.35 0.32 0.66 0.33 0.41 3.3

BCIPP (TCIPP) ND ND 0.45 0.18 0.20 1.3

Rarely used in electronics

BDCIPP (TDCIPP) 1.0 1.2 7.0 0.82 0.85 4.3

*Age 20 to 59, n = 1266, samples taken 2013 and 2014

†GM not calculated if proportion of results below the limit of detection was too high to provide a valid result.

‡n = 13 for this compound
Health Hazard Evaluation Report 2015-0050-3308 Page 49

Appendix B: Hand Wipe Sampling Pilot Study

We selected 12 processing employees from the disassembly, shredding, and battery sorting 

departments. We sampled their hands after their shift was over, but before they had washed 

their hands. We sampled six employees using sterile gauze wipes and six employees using 

twill wipes. Each group of employees included an even representation from the production 

departments. We presoaked two, 3 inch by 3 inch gauze pads or twill wipes in approximately 

6 ml of laboratory grade 99% isopropyl alcohol and placed them in a glass vial [Carignan et 

al. 2013]. We opened the glass vial, and asked the employee to take one wipe and wipe both 

palms from wrist to fingertips for 30 seconds, then place it back into the same glass vial. 

We then asked the employee to take the second wipe and repeat the process for the back of 

both hands and again place the wipe into the same glass vial. We sealed the vial with its lid 

and Parafilm®. Each employee performed this procedure three times, using new wipes and 

glass vials each time. We put on a new, clean pair of nitrile gloves during each step of the 

hand wipe sampling process to avoid cross contamination. For the 12 participants, we 

determined the percentage of 19 of the 24 individual flame retardants removed by each of 

the three sequential hand wipes by first summing the total amount removed and then 

dividing the amount removed on the first wipe, second wipe and the third wipe, by the total. 

We only included data for the participants that had all three sequential measures for a given 

flame retardant. 
Page 50 Health Hazard Evaluation Report 2015-0050-3308

Appendix C: Occupational Exposure Limits and 

Health Effects

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

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

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

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

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

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

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

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

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

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

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

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

Most OELs are expressed as a time-weighted average (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 limit (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.

● The U.S. Department of Labor OSHA permissible exposure limits (PELs) 

(29 CFR 1910 [general industry]; 29 CFR 1926 [construction industry]; and 29 CFR 

1917 [maritime industry]) are legal limits. These limits are enforceable in workplaces 

covered under the Occupational Safety and Health Act of 1970. 

● NIOSH RELs are recommendations based on a critical review of the scientific and 

technical information and the adequacy of methods to identify and control the hazard. 

NIOSH RELs are published in the NIOSH Pocket Guide to Chemical Hazards [NIOSH 

2010]. NIOSH also recommends risk management practices (e.g., engineering controls, 

safe work practices, employee education/training, PPE, and exposure and medical 

monitoring) to minimize the risk of exposure and adverse health effects.

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

threshold limit values (TLVs). The TLVs are developed by committee members of this 

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

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

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

control of health hazards” [ACGIH 2018].
Health Hazard Evaluation Report 2015-0050-3308 Page 51

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

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

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

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

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

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

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

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

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

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

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

reflect current health-based information.

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

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

decisions. NIOSH investigators also encourage use of the hierarchy of controls approach to 

eliminate or minimize workplace hazards. This includes, in order of preference, the use of (1) 

substitution or elimination of the hazardous agent, (2) engineering controls (e.g., local exhaust 

ventilation, process enclosure, dilution ventilation), (3) administrative controls (e.g., limiting 

time of exposure, employee training, work practice changes, medical surveillance), and (4) 

PPE (e.g., respiratory protection, gloves, eye protection, hearing protection). Control banding, 

a qualitative risk assessment and risk management tool, is a complementary approach to 

protecting employee health. Control banding focuses on how broad categories of risk should 

be managed. Information on control banding is available at http://www.cdc.gov/niosh/topics/

ctrlbanding/. This approach can be applied in situations where OELs have not been 

established or can be used to supplement existing OELs.

Flame Retardants

Flame retardants are added to manufactured materials, surface finishes, and coatings to 

inhibit, suppress, or delay the production of flames and impede the spread of fire. In 1975, 

California Technical Bill 117 required that upholstered furniture filling, which is usually 

polyurethane foam, meet an open flame test. Manufacturers added chemical flame retardants 

to foam to meet this standard. While the standard only applied in California, manufacturers 

sold Technical Bill 117-compliant products across the North America to avoid having double 

inventory and to minimize liability. California updated the standard in 2014 (TB117-2013). 

While it does not ban flame retardants, flammability safety standards can now be met 

without them.

PBDEs were used in a variety of products from the 1980s until recently. All PBDEs have 

a common structure of brominated diphenyl ether molecules with 1–10 bromine atoms 

attached. PBDEs have 209 different structural variations possible [Lorber 2008]. The 

manufacturing and import of the PentaBDE and OctaBDE formulations were phased out in 

2004 in the United States, and the production of DecaBDE ended in 2013. Manufacturers 
Page 52 Health Hazard Evaluation Report 2015-0050-3308

of flame retardants have introduced replacements for the PBDEs, but the toxicity of the 

replacements has not been well characterized [Allen et al. 2013]. These replacement 

compounds include novel brominated flame retardants like EH-TBB and BEH-TEBP, and 

phosphorus flame retardants like TDCIPP and TPHP. 

PBDEs have a molecular structure similar to thyroid hormones [McDonald 2002]. Some 

human epidemiologic studies have shown an association between exposure to PBDEs and 

changes in male reproductive hormones, semen quality, thyroid homeostasis, and hormone 

levels and fertility in women; cryptorchidism (undescended testicles); low birth weight and 

length; delayed motor skills; and decreased IQ [Abdallah et al. 2015; Czerska et al. 2013; 

Dallaire et al. 2009; Dishaw et al. 2014; Grant et al. 2013].

TPHP, BEH-TEBP, EH-TBB and isopropylated triphenyl phosphate isomers are components 

of Firemaster 550, which appears to be the second most common flame retardant mixture 

currently applied to foam, after TDCIPP [Hoffman et al. 2014]. Studies indicate that 

BEH-TEBP may affect thyroid hormones [Johnson et al. 2013]. TCEP and TCIPP are also 

used in some polyurethane foam. Some phosphorus flame retardants have been associated 

with decreased fertility, reduced sperm motility, altered reproductive and thyroid hormones, 

and cancer in humans [Dishaw et al. 2014; Meeker and Stapleton 2010; Meeker et al. 

2013a,b; van der Veen and de Boer 2012]. 

Exposure to flame retardants in indoor environments like homes, schools, and offices is 

thought to be mainly from ingestion of dust, primarily during the transfer of the flame 

retardants from hands to mouth, with dermal absorption the next most important route of 

exposure [Abdallah et al. 2015]. In contrast, a recent study estimated that inhalation exposure 

exceeded intake from ingestion of some chlorinated organophosphate flame retardants 

[Scheder et al. 2015]. Experimental data using human skin equivalent tissue demonstrates 

that absorption through skin increased as the number of bromine atoms decreased for PBDEs 

[Abdallah et al. 2015]. Animal studies show that TDCIPP is easily absorbed through the 

skin and gastrointestinal tract [Nomeir et al. 1981], and recent studies of human ex vivo 

skin showed absorption of 28% for TCEP, 25% for TCIPP, and 13% for TDCIPP 

[Abdallah et al. 2016]. 

Only two of the flame retardants have OSHA PELs, TPHP and TCP. The OSHA PEL for 

TPHP is 3,000,000 ng/m3 (3 mg/m3) while the PEL for tri-o-cresyl phosphate (one of the 

isomers of TCP) is 100,000 ng/m3 (0.1 mg/m3). The NIOSH REL and ACGIH TLV for TPHP 

are also 3 mg/m3. The NIOSH REL and ACGIH TLV are also 0.1 mg/m3. In addition, ATSDR 

[2013] recommends that if dust levels of PentaBDE and OctaBDE exceed 5,000,000 ng/m3 

(5 mg/m3) then periodic air monitoring should be required.

Lead

Inorganic lead is a naturally occurring, soft metal that has been mined and used in industry 

since ancient times. It comes in many forms (e.g., lead acetate, lead chloride, lead chromate, 

lead nitrate, lead oxide, lead phosphate, and lead sulfate). Lead is considered toxic to all 

organ systems and serves no useful purpose in the body.
Health Hazard Evaluation Report 2015-0050-3308 Page 53

Occupational exposure to inorganic lead occurs via inhalation of lead-containing dust and 

fume and ingestion of lead particles from contact with lead-contaminated surfaces. Exposure 

may also occur through transfer of lead to the mouth from contaminated hands or cigarettes 

when careful attention to hygiene, particularly hand washing, is not practiced. In addition 

to the inhalation and ingestion routes of exposure, lead can be absorbed through the skin, 

particularly through damaged skin [Filon et al. 2006; Stauber et al. 1994; Sun et al. 2002]. 

Workplace settings with exposure to lead and lead compounds include smelting and refining, 

scrap metal recovery, automobile radiator repair, construction and demolition (including 

abrasive blasting), and firing ranges. Occupational exposures also occur among workers who 

apply or remove lead-based paint and among welders who burn or torch-cut metal structures. 

Blood Lead Levels

In most cases, an individual’s blood lead level is a good indication of recent exposure to 

lead because the half-life of lead (the time interval it takes for the quantity in the body to 

be reduced by half its initial value) is 1–2 months [CDC 2013a; Lauwerys and Hoet 2001; 

Moline and Landrigan 2005]. Most lead in the body is stored in the bones, with a half-life 

of years to decades. Measuring bone lead, however, is primarily done only for research. 

Elevated zinc protoporphyrin levels have also been used as an indicator of chronic lead 

intoxication; however, other factors, such as iron deficiency, can cause an elevated zinc 

protoporphyrin level, so monitoring the BLL over time is more specific for evaluating 

chronic occupational lead exposure.

BLLs in adults in the United States have declined consistently over time. The GM BLL went 

from 1.75 μg/dL of whole blood in 1999–2000 to 1.09 μg/dL in 2011–2012 [CDC 2015b]. The 

NIOSH Adult Blood Lead Epidemiology and Surveillance System uses a surveillance case 

definition for an elevated BLL in adults of 5 μg/dL of blood or higher [CDC 2015a]. Very high 

BLLs are defined as being ≥ 40 μg/dL. From 2002–2011, occupational exposures accounted for 

91% of adults with very high BLLs (where exposure source was known) [CDC 2013b]. This 

underscores the need to increase efforts to prevent lead exposures in the workplace. 

Occupational Exposure Limits

In the United States, employers in general industry are required by law to follow the OSHA 

lead standard (29 CFR 1910.1025). This standard was established in 1978 and has not yet been 

updated to reflect the current scientific knowledge regarding the health effects of lead exposure. 

Under this standard, the OSHA PEL for airborne exposure to lead is 50 μg/m3 of air for an 

8-hour TWA. The standard requires lowering the PEL for shifts that exceed 8 hours, medical 

monitoring for employees exposed to airborne lead at or above the action level of 30 μg/m3

(8-hour TWA), medical removal of employees whose average BLL is 50 μg/dL or greater, 

and economic protection for medically removed workers. Medically removed workers cannot 

return to jobs involving lead exposure until their BLL is below 40 μg/dL. 

In the United States, other guidelines for lead exposure, which are not legally enforceable, 

are often followed. Similar to the OSHA lead standard, these guidelines were set years ago 

and have not yet been updated to reflect current scientific knowledge. NIOSH has a REL for 
Page 54 Health Hazard Evaluation Report 2015-0050-3308

lead of 50 μg/m3 averaged over an 8-hour work shift [NIOSH 2010]. ACGIH has a 

TLV for lead of 50 μg/m3 (8-hour TWA), with worker BLLs to be controlled to, or below, 

20 μg/dL. ACGIH designates lead as an animal carcinogen [ACGIH 2018]. In 2013, the 

California Department of Public Health recommended that Cal/OSHA lower the PEL for 

lead to 0.5 to 2.1 μg/m3 (8-hour TWA) to keep BLLs below the range of 5 to 10 μg/dL 

[Billingsley 2013].

Neither NIOSH nor OSHA has established surface contamination limits for lead in the 

workplace. The U.S. Environmental Protection Agency and the U.S. Department of Housing 

and Urban Development limit lead on surfaces in public buildings and child-occupied 

housing to less than 40 micrograms of lead per square foot [EPA 1998; HUD 2012]. OSHA 

requires in its substance-specific standard for lead that all surfaces be maintained as free as 

practicable of accumulations of lead [29 CFR 1910.1025(h)(1)]. An employer with workplace 

exposures to lead must implement regular and effective cleaning of surfaces in areas such 

as change areas, storage facilities, and lunchroom/eating areas to ensure they are as free as 

practicable from lead contamination. 

Health Effects

The PEL, REL, and TLV may prevent overt symptoms of lead poisoning, but do not protect 

workers from lead’s contributions to conditions such as hypertension, renal dysfunction, and 

reproductive and cognitive effects [Brown-Williams et al. 2009; Holland and Cawthorn 2016; 

Institute of Medicine 2012; Schwartz and Hu 2007; Schwartz and Stewart 2007]. Generally, 

acute lead poisoning with symptoms has been documented in persons having BLLs above 

70 μg/dL. These BLLs are rare today in the United States, largely as a result of workplace 

controls put in place to comply with current OELs. When present, acute lead poisoning 

can cause myriad adverse health effects including abdominal pain, hemolytic anemia, and 

neuropathy. Lead poisoning has, in very rare cases, progressed to encephalopathy and coma 

[Moline and Landrigan 2005]. 

People with chronic lead poisoning, which is more likely at current occupational exposure 

levels, may not have symptoms or they may have nonspecific symptoms that may not be 

recognized as being associated with lead exposure. These symptoms include headache, joint 

and muscle aches, weakness, fatigue, irritability, depression, constipation, anorexia, and 

abdominal discomfort [Moline and Landrigan 2005]. 

The National Toxicology Program recently released a monograph on the health effects of 

low-level lead exposure [National Toxicology Program 2012]. For adults, the National 

Toxicology Program concluded the following about the evidence regarding health effects of 

lead (Table C1).
Health Hazard Evaluation Report 2015-0050-3308 Page 55

Various organizations have assessed the relationship between lead exposure and cancer. 

According to the Agency for Toxic Substances and Disease Registry [ATSDR 2007] and 

the National Toxicology Program [NTP 2011], inorganic lead compounds are reasonably 

anticipated to cause cancer in humans. The International Agency for Research on Cancer 

classifies inorganic lead as probably carcinogenic to humans [IARC 2006a]. According 

to the American Cancer Society [ACS 2011], some studies show a relationship between 

lead exposure and lung cancer, but these results might be affected by exposure to cigarette 

smoking and arsenic. Some studies show a relationship between lead and stomach cancer, 

and these findings are less likely to be affected by the other exposures. The results of studies 

looking at other cancers, including brain, kidney, bladder, colon, and rectum, are mixed.

Table C1. Evidence regarding health effects of lead in adults

Health area NTP 

conclusion

Principal health effects Blood lead 

evidence

Neurological Sufficient Increased incidence of essential tremor Yes, < 10 μg/dL

Limited Psychiatric effects, decreased hearing, 

decreased cognitive function, increased 

incidence of amyotrophic lateral sclerosis

Yes, < 10 μg/dL

Limited Increased incidence of essential tremor Yes, < 5 μg/dL

Immune Inadequate Unclear

Cardiovascular Sufficient Increased blood pressure and increased risk 

of hypertension

Yes, < 10 μg/dL

Limited Increased cardiovascular-related mortality 

and electrocardiography abnormalities

Yes, < 10 μg/dL

Renal Sufficient Decreased glomerular filtration rate Yes, < 5 μg/dL

Reproductive Sufficient Women: reduced fetal growth Yes, < 5 μg/dL

Sufficient Men: adverse changes in sperm parameters 

and increased time to pregnancy

Yes, ≥ 15–20 μg/dL

Limited Women: increase in spontaneous abortion 

and preterm birth

Yes, < 10 μg/dL

Limited Men: decreased fertility Yes, ≥ 10 μg/dL

Limited Men: spontaneous abortion Yes, ≥ 31 μg/dL

Inadequate Women and Men: stillbirth, endocrine effects, 

birth defects

Unclear
Page 56 Health Hazard Evaluation Report 2015-0050-3308

Medical Management

To prevent acute and chronic health effects, a panel of experts convened by the Association 

of Occupational and Environmental Clinics published guidelines for the management of 

adult lead exposure [Kosnett et al. 2007]. The panel recommended BLL testing for all leadexposed employees, regardless of the airborne lead concentration. These recommendations 

do not apply to pregnant women, who should avoid BLLs > 5 μg/dL. Removal from lead 

exposure should be considered if control measures over an extended period do not decrease 

BLLs to < 10 μg/dL or an employee has a medical condition that would increase the risk of 

adverse health effects from lead exposure. These guidelines were endorsed by the Council of 

State and Territorial Epidemiologists and the California Department of Public Health in 2009 

and the American College of Occupational and Environmental Medicine in 2010 [ACOEM 

2010; CDPH 2009; CSTE 2009]. The Council of State and Territorial Epidemiologists 

published updated guidelines in 2013 to reflect the new definition of an elevated BLL in 

adults of 5 μg/dL [CSTE 2015]. The California Department of Public Health recommended 

keeping BLLs below 5 to 10 μg/dL in 2013 [Billingsley 2013] and updated their medical 

management guidelines in 2014 [CDPH 2014]. In 2015, NIOSH designated 5 μg/dL of whole 

blood, in a venous blood sample, as the reference blood lead level for adults. An elevated 

BLL is defined as a BLL ≥ 5 μg/dL. In 2016, the American College of Occupational and 

Environmental Medicine released a position statement entitled “Workplace Lead Exposure,” 

which reinforces the guidelines and recommendations above [Holland and Cawthorn 2016]. 

Table C2 incorporates recommendations from the expert panel guidelines and those from 

CDPH, ACOEM, and CSTE. 
Health Hazard Evaluation Report 2015-0050-3308 Page 57

Table C2. Health-based medical surveillance recommendations for lead-exposed employees

Category of exposure Recommendations

All lead exposed workers ● Baseline or preplacement medical history and physical 

examination, baseline BLL, and serum creatinine

BLL < 5 μg/dL ● BLL monthly for first 3 months placement, or upon change in 

task to higher exposure, then BLL every 6 months; if BLL 

increases ≥ 5 μg/dL, evaluate exposure and protective measures, 

and increase monitoring if indicated

BLL 5–9 μg/dL ● Discuss health risks

● Minimize exposure

● Consider removal for pregnancy and certain medical conditions

● BLL monthly for first 3 months placement or every 2 months for 

the first 6 months placement, or upon change in task to higher 

exposure, then BLL every 6 months; if BLL increases ≥ 5 μg/dL, 

evaluate exposure and protective measures, and increase 

monitoring if indicated

BLL 10–19 μg/dL ● Discuss health risks

● Decrease exposure

● Remove from exposure for pregnancy

● Consider removal for certain medical conditions or BLL > 10 μg/dL 

for extended period

● BLL every 3 months; evaluate exposure, engineering controls, and 

work practices; consider removal. 

● Revert to BLL every 6 months after 3 BLLs < 10 μg/dL

BLL 20–29 μg/dL ● Remove from exposure for pregnancy

● Remove from exposure if repeat BLL measured in 4 weeks 

remains ≥ 20 μg/dL

● Annual lead medical exam recommended

● Monthly BLL testing

● Consider return to work after 2 BLLs < 15 μg/dL a month apart, 

then monitor as above

BLL 30–49 μg/dL ● Remove from exposure

● Prompt medical evaluation

● Monthly BLL testing

● Consider return to work after 2 BLLs < 15 μg/dL a month apart, 

then monitor as above

BLL 50–79 μg/dL ● Remove from exposure

● Prompt medical evaluation

● Consider chelation with significant symptoms

BLL > 80 μg/dL ● Remove from exposure

● Urgent medical evaluation

● Chelation may be indicated

Adapted from Kosnett et al. 2007, CSTE 2015, and CDPH 2014
Page 58 Health Hazard Evaluation Report 2015-0050-3308

Take-home Contamination

Occupational exposures to lead can result in exposures to household members, including 

children, from take-home contamination. Take-home contamination occurs when lead dust is 

transferred from the workplace on employees’ skin, clothing, shoes, and other personal items 

to their vehicle and home [CDC 2009, 2012]. 

The Centers for Disease Control and Prevention considers a BLL in children of 5 μg/dL or 

higher as a reference level above which public health actions should be initiated, and states 

that no safe BLL in children has been identified [CDC 2013a].

The U.S. Congress passed the Workers’ Family Protection Act in 1992 (29 U.S.C. 671a). 

The Act required NIOSH to study take-home contamination from workplace chemicals and 

substances, including lead. NIOSH found that take-home exposure is a widespread problem 

[NIOSH 1995]. Workplace measures effective in preventing take-home exposures were 

(1) reducing exposure in the workplace, (2) changing clothes before going home and leaving 

soiled clothing at work for laundering, (3) storing street clothes in areas separate from work 

clothes, (4) showering before leaving work, and (5) prohibiting removal of toxic substances 

or contaminated items from the workplace. NIOSH noted that preventing take-home 

exposure is critical because decontaminating homes and vehicles is not always effective. 

Normal house cleaning and laundry methods are inadequate, and decontamination can expose 

the people doing the cleaning and laundry. 

Beryllium, Cadmium, Chromium, Nickel, Manganese, 

and Cobalt

Below, Table C3 summarizes the OELs for the other common metals found in electronic 

recycling, as well as a discussion of the potential health effects from exposure to these elements.
Health Hazard Evaluation Report 2015-0050-3308 Page 59

Table C3. Chemical health effects

Chemicals Health effects IARC OEL (μg/m3)

Beryllium ● Beryllium exposure may cause 

dermatitis, lung inflammation, 

and chronic beryllium disease in 

humans [Proctor et al. 1991]

● Exposure to beryllium can lead 

to sensitization

● Exposure also slightly increases 

the risk for lung cancer 

[Schubauer-Berigan et al. 2010]

Group 1: 

carcinogenic 

to humans 

[IARC 2012]

OSHA PEL: 2.0

NIOSH REL: 0.5

ACGIH TLV: 0.05

Cadmium ● Long-term occupational exposure to 

cadmium is associated with 

increased occurrence of lung cancer, 

kidney damage, and chronic 

obstructive lung disease 

[WHO 1992]

Group 1: 

carcinogenic 

to humans 

[IARC 2012]

OSHA PEL: 5.0

NIOSH REL: Cancer

ACGIH TLV: 10 

(2 respirable fraction)

Chromium ● The toxic effects of chromium 

exposure, including lung and nasal 

cancer, are primarily related to 

hexavalent chromium

● Skin exposure to chromium dust 

can cause skin irritation and skin 

ulceration, and allergic contact 

dermatitis

Group 1: 

carcinogenic 

to humans 

[IARC 2012]

OSHA PEL: 1,000

NIOSH REL: 500

ACGIH TLV: 500

Nickel ● Allergic contact dermatitis, 

respiratory irritation, chronic 

bronchitis, asthma, reduced lung 

function

Nickel 

compounds, 

Group 1: 

carcinogenic to 

humans; 

paranasal 

sinus, nasal 

cavity, and lung

OSHA PEL: 1,000

NIOSH REL: 15

ACGIH TLV: 1,500

Manganese ● Subclinical neurological effects, such 

as decreased performance on 

neurobehavioral tests; significantly 

poorer eye-hand coordination, hand 

steadiness, and reaction time; poorer 

postural stability; and lower levels of 

cognitive flexibility

None OSHA PEL: 5,000

NIOSH REL: 1,000

ACGIH TLV: 100

Cobalt ● Exposure to elevated levels of 

cobalt can cause gastrointestinal 

irritation, nausea, and vomiting

● Inhaled cobalt can lead to lung 

damage

● Skin exposure can cause irritant 

and allergic contact dermatitis 

[Vincoli 1997]

Group 2B: 

possibly 

carcinogenic 

to humans 

[IARC 2006b]

OSHA PEL: 100

NIOSH REL: 50

ACGIH TLV: 20

IARC = International Agency for Research on Cancer
Page 60 Health Hazard Evaluation Report 2015-0050-3308

Indium and Indium Nanoparticles

Nanotechnology is the manipulation of matter on a near-atomic scale to product new 

structures, materials, and devices. Nanomaterials or nano-objects are defined according to 

ISO/TS 27687:2008 as material with one, two, or three external dimensions in the size range 

of approximately 1–100 nanometers (nm), or 1,000 times smaller than a micrometer. This 

includes engineered nanomaterials and ultrafine particles. Engineered nanomaterials are 

intentionally produced nanomaterials, whereas ultrafine particles or incidental nanoparticles 

are typically byproducts of processes such as combustion or vaporization [NIOSH 2009b]. 

Nanomaterials may have properties that are different from those of larger particles of the 

same material, which makes them unique and desirable for specific product applications. 

Nanomaterials have greater surface-area-to-mass ratios when compared to larger particles 

of the same material. This and other properties such as size, surface area, shape, chemistry, 

solubility, agglomeration, and biopersistence makes them generally more reactive than 

their larger-sized counterparts, and may increase their toxicity [NIOSH 2014b]. Engineered 

nanomaterials and ultrafine particles are a health concern because recent studies have shown 

that the toxicity of these ultrafine or engineered nanoparticles is greater than that of the same 

mass of larger particles of similar chemical composition [NIOSH 2009b]. 

Indium, including indium oxide, indium tin oxide and particularly indium nanoparticles, are 

widely used as a thin coating or conductive film on touch screens, flat panel displays such 

as LCD televisions, computer screens, solar panels, and aircraft and automobile windows 

[National Toxicology Program 2009]. Occupational exposure to indium metals may cause 

eye, skin, and respiratory system irritation, liver, kidney, heart and blood effects, pulmonary 

edema and lung damage [National Toxicology Program 2009; NIOSH 2010].

The OELs for indium (including indium compounds) includes the NIOSH REL of 0.1 mg/m3, 

as an 8-hour time weighted average [NIOSH 2010] and the ACGIH 8-hr TWA TLV of 

0.1 mg/m3 [ACGIH 2018]. However, there is not a specific OEL for nanoscale indium particles 

for example, which may be present in coatings on LCD screens shredded in this study. 

Presently, limited data are available to characterize the potential health risks associated with 

occupational exposure to indium nanoparticles. The results of experimental in vivo and in vitro 

studies indicate that size of the particle is critical to subsequent biological effects, raising the 

possibility that indium nanoparticles may have the potential to be more hazardous than larger 

sized particles, and may exhibit mutagenic properties [Hasegawa et al. 2012; Lim et al. 2014].
Health Hazard Evaluation Report 2015-0050-3308 Page 61

Appendix D: Operation of the Direct-reading 

Instruments

The condensation particle counter operates by drawing air through a size-selective inlet, 

passing it through a heated saturator filled with isopropyl alcohol, and then cooling the 

air stream via a condenser chamber. In the condenser, the alcohol vapor condenses on the 

particles until the particle size reaches approximately 10 μm in diameter. This process allows 

the condensation particle counter optical detector to count particles in the size range of 

10‒1,000 nm. The data output is expressed as total number of p/cc of sampled air, with an 

upper dynamic range limit of approximately 100,000 p/cc [TSI Incorporated 2012].

The OPS 3330 is an aerosol photometer, which illuminates an aerosol passing through a 

defined volume, and then detecting the total light scattered by all particles in that defined 

volume. The OPS 3330 allows the user to define 16 sizes ranges (also called bins) ranging 

from 0.3 μm (or 300 nm) to 10 μm. The counting efficiency of optical particle sizers using 

laser photometry has been shown to gradually decline as the aerodynamic diameter of the 

sampled aerosol decreases. According to TSI, the counting efficiency of the OPS 3330 is 50% 

at 300 nm. The OPS 3330 approaches 100% counting efficiency at 500 nm. The OPS 3330 is 

capable of accurately measuring aerosols at concentrations up to 3,000 p/cc. 

The DustTrak operates by passing sampled air through a chamber illuminated by a laser. 

The light scattered by particles is measured at a 90° angle using a solid-state silicon photodetector. The intensity of the scattered light is a function of the particle mass concentration 

and the size distribution and composition of the aerosol. We used this instrument to estimate 

the aerosol mass concentration of particles smaller than 15,000 nm in aerodynamic diameter. 

Aerosol photometers like the TSI DustTrak provide estimates based upon assumed density 

and particle size distributions. According to TSI, this instrument will respond to particles 

in the size range of 100 nm to approximately 15,000 nm, and aerosol mass concentrations 

ranging from 1‒150,000 μg/m3 [TSI Incorporated 2014]. However, detector sensitivity 

declines for particles smaller than 250 nm in diameter. 

The Jerome® model J505 atomic fluorescence mercury vapor analyzer measures mercury 

vapor concentrations in the air. The instrument contains a mercury light source that is 

energized to emit light at 254 nm wavelength into a sample cell, which corresponds to the 

wavelength of light that mercury atoms absorb light. When mercury atoms absorb the light, 

it gets re-emitted at the same wavelength. A photo multiplier tube measures the light emitted 

at 90° to the source, correlating to the mercury concentration in the air. Air is drawn into 

the instrument at approximately 1 liter per minute. We used this instrument to estimate the 

mercury vapor concentration in μg/m3 of air. The Jerome J505 responds to mercury vapor 

concentrations in ambient air of 0.05–500 μg/m3 of air [Arizona Instrument LLC 2014].
Page 62 Health Hazard Evaluation Report 2015-0050-3308

References

Abdallah MA, Pawar G, Harrad S [2015]. Effect of bromine substitution on human dermal 

absorption of polybrominated diphenyl ethers. Environ Sci Technol 49(18):10976–10983, 

http://dx.doi.org/10.1021/acs.est.5b03904.

Abdallah MA, Pawar G, Harrad S [2016]. Human dermal absorption of chlorinated 

organophosphate flame retardants; implications for human exposure. Toxicol Appl Pharmacol 

291:28–37, http://dx.doi.org/10.1016/j.taap.2015.12.004.

ACGIH [2018]. 2018 TLVs® and BEIs®: threshold limit values for chemical substances and 

physical agents and biological exposure indices. Cincinnati, OH: American Conference of 

Governmental Industrial Hygienists.

ACOEM [2010]. ACOEM provides input to OSHA on key issues facing agency in 2010. 

Letter to David Michaels. Elk Grove Village, IL: American College of Occupational and 

Environmental Medicine, http://www.acoem.org/Page2Column.aspx?PageID=7392&id=6676.

ACS [2011]. Lead. Atlanta, GA: American Cancer Society, 

http://www.cancer.org/cancer/cancercauses/othercarcinogens/athome/lead. 

Adams SV, Newcomb PA [2014]. Cadmium blood and urine concentrations as measures of 

exposure: NHANES 1999-2010. J Expo Sci Environ Epidemiol 24(2):163–170, 

http://dx.doi.org/10.1038/jes.2013.55.

Alaee, M, Arias P, Sjodin A, Bergman A [2003]. An overview of commercially used 

brominated flame retardants, their applications, their use patterns in different countries/

regions and possible modes of release. Environ Int 29(6):683–689, 

http://dx.doi.org/10.1016/S0160-4120(03)00121-1.

Allen JG, McClean MD, Stapleton HM, Nelson JW, Webster TF [2007]. Personal exposure 

to polybrominated diphenyl ethers (PBDEs) in residential indoor air. Environ Sci Technol 

41(13):4574–4579, http://dx.doi.org/10.1021/es0703170.

Allen JG, Stapleton HM, Vallarino J, McNeely E, McClean MD, Harrad SJ, Rauert CB, 

Spengler JD [2013]. Exposure to flame retardant chemicals on commercial airplanes. Env 

Health 12:17, http://dx.doi.org/10.1186/1476-069X-12-17.

ANSI/ASHRAE [2016]. Ventilation for acceptable indoor quality. American National 

Standards Institute/ASHRAE standard 62.1-2016. Atlanta, GA: ASHRAE.

Arizona Instrument LLC [2014]. Jerome® J505 mercury vapor analyzer operation manual. 

Chandler, AZ: Arizona Instrument LLC.

ATSDR [2007]. Toxicological profile for lead. Atlanta, GA: U.S. Department of Health and 

Human Services, Agency for Toxic Substances and Disease Registry.
Health Hazard Evaluation Report 2015-0050-3308 Page 63

ATSDR [2013]. Toxicological profile for polybrominated biphenyls and polybrominated 

diphenyl ethers. Atlanta, GA: U.S. Department of Health and Human Services, Agency for 

Toxic Substances and Disease Registry, http://www.atsdr.cdc.gov/toxprofiles/tp68.pdf.

Bergman A, Rydén A, Law RJ, de Boer J, Covaci A, Alaee M, Birnbaum L, Petreas M, 

Rose M, Sakai S, Van den Eede N, van der Veen I [2012]. A novel abbreviation standard for 

organobromine, organochlorine and organophosphorus flame retardants and some characteristics 

of the chemicals. Environ Int 49C:57–82, http://dx.doi.org/10.1016/j.envint.2012.08.003.

Billingsley KJ [2013]. Letter of September 30, 2013, from K. J. Billingsley, California 

Department of Public Health, to Juliann Sum, Division of Occupational Safety and Health 

(Cal/OSHA), California Department of Industrial Relations. 

Brown-Williams H, Lichterman J, Kosnett M [2009]. Indecent exposure: lead puts workers 

and families at risk. Health Research in Action, University of California, Berkeley. 

Perspectives 4(1):1–9.

Carignan CC, Heiger-Bernays W, McClean MD, Roberts SC, Stapleton HM, Sjödin A, 

Webster TF [2013]. Flame retardant exposure among collegiate United States gymnasts. 

Environ Sci Technol 47(23):13848–13856, http://dx.doi.org/10.1021/es4037868.

Carignan CC, Fang M, Stapleton HM, Heiger-Bernays W, McClean MD, Webster TF [2016]. 

Urinary biomarkers of flame retardant exposure among collegiate U.S. gymnasts. Environ Int 

94:362–368, http://dx.doi.org/10.1016/j.envint.2016.06.030.

Carlsson H, Nilsson U, Becker G, Östman C [1997]. Organophosphate ester flame retardants 

and plasticizers in the indoor environment:Analytical methodology and occurrence. Environ 

Sci Technol 31(10):2931–2936, http://dx.doi.org/10.1021/es970123s.

CDC (Centers for Disease Control and Prevention) [2009]. Childhood lead poisoning associated 

with lead dust contamination of family vehicles and child safety seats --- Maine, 2008. MMWR 

58(32):890–893, https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5832a2.htm.

CDC (Centers for Disease Control and Prevention) [2012]. Adult blood lead epidemiology 

and surveillance (ABLES), http://www.cdc.gov/niosh/topics/ABLES/description.html.

CDC (Centers for Disease Control and Prevention) [2013a]. Blood lead levels in children 

aged 1–5 years — United States, 1999–2010. MMWR 62(13):245–248, 

https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6213a3.htm.

CDC (Centers for Disease Control and Prevention) [2013b]. Very high blood lead levels 

among adults — United States, 2002–2011. MMWR 62(47):967–971, 

https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6247a6.htm.

CDC (Centers for Disease Control and Prevention) [2015a]. Adult blood lead epidemiology 

and surveillance (ABLES), http://www.cdc.gov/niosh/topics/ables/description.html. 
Page 64 Health Hazard Evaluation Report 2015-0050-3308

CDC (Centers for Disease Control and Prevention) [2015b]. Fourth national report on human 

exposure to environmental chemicals updated tables, February, 2015, 

http://www.cdc.gov/biomonitoring/pdf/FourthReport_UpdatedTables_Feb2015.pdf. 

CDC (Centers for Disease Control and Prevention) [2018]. National report on Human Exposure 

to Environmental Chemicals updated tables, March 2018, https://www.cdc.gov/exposurereport/.

CDPH [2009]. Medical guidelines for the lead‐exposed worker. Sacramento, CA: California 

Department of Public Health, Occupational Lead Poisoning Prevention Program, 

http://www.cdph.ca.gov/programs/olppp/Documents/medgdln.pdf. 

CDPH [2014]. Management guidelines for blood lead levels in adults. Sacramento, CA: 

California Department of Public Health, Occupational Lead Poisoning Prevention Program, 

http://www.cdph.ca.gov/programs/olppp/documents/adultmgtguide.pdf.

Ceballos D, Dong Z [2016]. The formal electronic recycling industry: environmental and 

occupational health research challenges and opportunities. Environ Int 95:157–166, 

http://dx.doi.org/10.1016/j.envint.2016.07.010.

Ceballos D, Beaucham C, Page E [2016]. Metal exposures at three U.S. electronic scrap 

recycling facilities. J Occup Environ Med 14(6):401–408, 

http://dx.doi.org/10.1080/15459624.2016.1269179.

CFR. Code of Federal Regulations. Washington, DC: U.S. Government Printing Office, 

Office of the Federal Register.

Cooper EM, Covaci A, vanNuijs AL, Webster TF, Stapleton HM [2011]. Analysis of the 

flame retardant metabolites bis(1,3-dichloro-2-propyl) phosphate (BDCPP) and diphenyl 

phosphate (DPP) in urine using liquid chromatography-tandem mass spectrometry. Anal 

Bioanal Chem 401(7):2123–2132, http://dx.doi.org/10.1007/s00216-011-5294-7.

CSTE [2009]. Proposal to adopt new or amended surveillance definitions for four environmental 

conditions. CSTE position statement 09-OH-02. Atlanta, GA: Council of State and Territorial 

Epidemiologists, http://c.ymcdn.com/sites/www.cste.org/resource/resmgr/PS/09-OH-02.pdf.

CSTE [2015]. Public health reporting and national notification for elevated blood lead levels. 

CSTE position statement 15-eH-01. Atlanta, GA: Council of State and Territorial Epidemiologists, 

http://c.ymcdn.com/sites/www.cste.org/resource/resmgr/2015PS/2015PSFinal/15-EH-01.pdf.

Czerska M, Zieliński M, Kamińska J, Ligocka D [2013]. Effects of polybrominated diphenyl 

ethers on thyroid hormone, neurodevelopment and fertility in rodents and humans. Int J 

Occup Med Environ Health 26(4):498–510, http://dx.doi.org/10.2478/s13382-013-0138-7.

Dallaire R, Dewailly É, Pereg D, Dery S, Ayotte P [2009]. Thyroid function and plasma 

concentrations of polyhalogenated compounds in Inuit adults. Environ Health Perspect 

117:1380–1386, https://dx.doi.org/10.1289/ehp.0900633.
Health Hazard Evaluation Report 2015-0050-3308 Page 65

Dishaw LV, Macaulay LJ, Roberts SC, Stapleton HM [2014]. Exposures, mechanisms, and 

impacts of endocrine-active flame retardants. Curr Opin Pharmacol 19:125–133, 

http://dx.doi.org/10.1016/j.coph.2014.09.018.

Dodson RE, Van den Eede, Covaci A, Petrovich LJ, Brody JG, Rudel RA [2014]. Urinary 

biomarkers of phosphate flame retardants: levels in California adults and recommendations for 

future studies. Environ Sci Technol 48(23):13625–13633, http://dx.doi.org/10.1021/es503445c.

EPA [1998]. Risk analysis to support standards for lead in paint, dust, and soil. EPA 

Publication EPA-747-R097-006. Washington, D.C.: U.S. Environmental Protection Agency

http://www2.epa.gov/lead/risk-analysis-support-standards-lead-paint-dust-and-soil-volume-ichapters-1-7-and-appendix-epa. 

Esswein EJ, Boeniger MF, Ashley K [2011]. Handwipe method for removing lead from skin. 

J ASTM International 8(5):1–10, https://doi.org/10.1520/JAI103527.

Filon FL, Boeniger M, Maina G, Adami G, Spinelli P, Damian A [2006]. Skin absorption of 

inorganic lead (PbO) and the effect of skin cleansers. J Occup Environ Med 48(7):692–699, 

http://dx.doi.org/10.1097/01.jom.0000214474.61563.1c.

Grant K, Goldizen FC, Sly PD, Brune MN, Neira M, van den Berg M, Norman RE [2013]. 

Health consequences of exposure to e-scrap: a systematic review. The Lancet Global Health 

1(6):e350–e361, http://dx.doi.org/10.1016/S2214-109X(13)70101-3.

Hammel SC, Hoffman K, Webster TF, Anderson KA, Stapleton HM [2016]. Measuring 

personal exposure to organophosphate flame retardants using silicone wristbands and hand 

wipes. Environ Sci Technol 50(8):4483–4491, http://dx.doi.org/10.1021/acs.est.6b00030.

Hasegawa G, Shimonaka M, Ishihara Y [2012]. Differential genotoxicity of chemical 

properties and particle size of rare metal and metal oxide nanoparticles. J Appl Toxicol 

32(1):72–80, http://dx.doi.org/10.1002/jat.1719.

Hoffman K, Fang M, Horman B, Patisaul HB, Garantziotis S, Birnbaum LS, Stapleton HM 

[2014]. Urinary tetrabromobenzoic acid (TBBA) as a biomarker of exposure to the flame 

retardant mixture Firemaster® 550. Environ Health Perspect 122(9):963–969, 

http://dx.doi.org/10.1289/ehp.1308028.

Hoffman K, Garantziotis S, Birnbaum LS, Stapleton HM [2015]. Monitoring indoor exposure 

to organophosphate flame retardants: hand wipes and house dust. Environ Health Perspect 

123(2):160–165, http://dx.doi.org/10.1289/ehp.1408669.

Holland MG, Cawthorn D [2016]. ACOEM position statement: workplace lead exposure. 

JOEM 58(12):371–373, https://dx.doi.org/10.1097/JOM.0000000000000928.

Hornung RW, Reed LD [1990]. Estimation of average concentration in the presence of 

nondetectable values. Appl Occup Environ Hyg 5(1):46–51, 

http://dx.doi.org/10.1080/1047322x.1990.10389587.
Page 66 Health Hazard Evaluation Report 2015-0050-3308

HUD [2012]. Guidelines for the evaluation and control of lead-based paint hazards in housing, 

http://portal.hud.gov/hudportal/HUD?src=/program_offices/healthy_homes/lbp/hudguidelines. 

IARC [2006a]. IARC monographs on the evaluation of carcinogenic risks to humans: 

inorganic and organic lead compounds. Volume 87. Lyon, France: World Health 

Organization, International Agency for Research on Cancer.

IARC [2006b]. IARC monographs on the evaluation of carcinogenic risks to humans: 

cobalt in hard metals and cobalt sulfate, gallium arsenide, indium phosphide and vanadium 

pentoxide. Volume 86. Lyon, France: World Health Organization, International Agency for 

Research on Cancer.

IARC [2012]. IARC monographs on the evaluation of carcinogenic risks to humans: 

arsenic, metals, fibres and dusts. Volume 100C. Lyon, France: World Health Organization, 

International Agency for Research on Cancer.

Institute of Medicine [2012]. Potential health risks from recurrent lead exposure of DOD 

firing range personnel. Washington, D.C.: National Academies Press. 

Jakobsson K, Thuresson K, Rylander L, Sjödin A, Hagmar L, Bergman A [2002]. Exposure 

to polybrominated diphenyl ethers and tetrabromobisphenol A among computer technicians. 

Chemosphere 46(5):709–716, https://doi.org/10.1016/S0045-6535(01)00235-1.

Jayatilaka NK, Restrepo P, Williams L, Ospina M, Valentin-Blasini L, Calafat AM 

[2017]. Quantification of three chlorinated dialkyl phosphates, diphenyl phosphate, 

2,3,4,5-tetrabromobenzoic acid, and four other organophosphates in human urine by solid 

phase extraction-high performance liquid chromatography-tandem mass spectrometry. Anal 

Bioanal Chem 409(5):1323–1332, http://dx.doi.org/10.1007/s00216-016-0061-4.

Johnson PI, Stapleton HM, Mukherjee B, Hauser R, Meeker JD [2013]. Associations between 

brominated flame retardants in house dust and hormone levels in men. Sci Total Environ 

445–446:177–184, http://dx.doi.org/10.1016/j.scitotenv.2012.12.017.

Kosarac I, Kubwabo C, Foster W [2016]. Quantitative determination of nine urinary 

metabolites of organophosphate flame retardants using solid phase extraction and ultra 

performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS). 

J Chromatogr B 1014:24–30, http://dx.doi.org/10.1016/j.jchromb.2016.01.035.

Kosnett MJ, Wedeen RP, Rothenberg SJ, Hipkins KL, Materna BL, Schwartz BS, Hu H, 

Woolf A [2007]. Recommendations for medical management of adult blood lead exposure. 

Environ Health Perspect 115(3):463–471, http://dx.doi.org/10.1289/ehp.9784.

Kurebayashi H, Tanaka A, Yamaha T [1985]. Metabolism and disposition of the flame-retardant 

plasticizer, tri-para-cresyl phosphate, in the rat. Toxicol Appl Pharmacol 77(3):395–404.

La Guardia MJ, Hale RC, Harvey E [2006]. Detailed polybrominated diphenyl ether (PBDE) 

congener composition of the widely used Penta-, Octa-, and Deca-PBDE technical flame-retardant 

mixtures. Environ Sci Technol 40(2):6247–6254, http://dx.doi.org/ 10.1021/es060630m.
Health Hazard Evaluation Report 2015-0050-3308 Page 67

La Guardia MJ, Hale RC [2015]. Halogenated flame-retardant concentrations in settled dust, 

respirable and inhalable particulates and polyurethane foam at gymnastic training facilities 

and residences. Environ Int 79:106–114, http://dx.doi.org/10.1016/j.envint.2015.02.014.

Lauwerys RR, Hoet P [2001]. Industrial chemical exposure: guidelines for biological 

monitoring. 3rd ed. Boca Raton, FL: CRC Press, LLC, pp. 21–180.

Lim CH, Han JH, Cho HW, Kang M [2014]. Studies on the toxicity and distribution of 

indium compounds according to particle size in Sprague-Dawley rats. Toxicological 

Research 30(1):55–63, http://dx.doi.org/10.5487/TR.2014.30.1.055.

Lorber M [2008]. Exposure of Americans to polybrominated diphenyl ethers. J Expo Sci 

Environ Epidemiol 18(1):2–19, http://dx.doi.org/10.1038/sj.jes.7500572. 

Mäkinen MS, Mäkinen MR, Koistinen JT, Pasanen AL, Pasanen PO, Kalliokoski PJ, Korpi 

AM [2009]. Respiratory and dermal exposure to organophosphorus flame retardants and 

tetrabromobisphenol A at five work environments. Environ Sci Technol 43(3):941–947, 

http://dx.doi.org/10.1021/es802593t.

Mannino DM, Homa DM, Matte T, Hernandez-Avila M [2005]. Active and passive smoking and

blood lead levels in U.S. adults: data from the Third National Health and Nutrition Examination

Survey. Nicotine Tob Res 7(4):557–564, http://dx.doi.org/10.1080/14622200500185264.

McDonald TA [2002]. A perspective on the potential health risks of PBDEs. Chemosphere 

46(5):745–755, http://dx.doi.org/10.1016/S0045-6535(01)00239-9.

Meeker JD, Stapleton HM [2010]. House dust concentrations of organophosphate flame 

retardants in relation to hormone levels and semen quality parameters. Environ Health 

Perspect 118(3):318–323, http://dx.doi.org/10.1289/ehp.0901332. 

Meeker JD, Cooper EM, Stapleton HM, Hauser R [2013a]. Exploratory analysis of urinary 

metabolites of phosphorus-containing flame retardants in relation to markers of male 

reproductive health. Endocr Disruptors (Austin) 1(1):e26306, 

http://dx.doi.org/10.4161/endo.26306.

Meeker JD, Cooper EM, Stapleton HM, Hauser R [2013b]. Urinary metabolites of

organophosphate flame retardants: temporal variability and correlations with house dust

concentrations. Environ health perspect 121(5):580–585, http://dx.doi.org/10.1289/ehp.1205907.

Moline JM, Landrigan PJ [2005]. Lead. In: Rosenstock L, Cullen MR, Brodkin CA, 

Redlich CA, eds. Textbook of clinical occupational and environmental medicine. 2nd ed. 

Philadelphia, PA: Elsevier Saunders, pp. 967–979.

Newman N, Jones C, Page E, Ceballos D, Oza A [2015]. Investigation of childhood lead 

poisoning from parental take-home exposure from an electronic scrap recycling facility – 

Ohio, 2012. MMWR 64(27):743–745, 

https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6427a3.htm.
Page 68 Health Hazard Evaluation Report 2015-0050-3308

NIOSH [1995]. Report to Congress on the workers’ home contamination study conducted 

under the Workers’ Family Protection Act 29 U.S.C. 671a. Cincinnati, OH: U.S. 

Departmentof Health and Human Services, Centers for Disease Control and Prevention, 

National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 

95-123, http://www.cdc.gov/niosh/docs/95-123/. 

NIOSH [2009a]. Exposure to hazardous metals during electronics recycling at four UNICOR 

facilities. By Page E, Sylvain D. Cincinnati, OH: U.S. Department of Health and Human 

Services, Centers for Disease Control and Prevention, National Institute for Occupational 

Safety and Health, Health Hazard Evaluation Report 2008-0055-3098, 

https://www.cdc.gov/niosh/hhe/reports/pdfs/2008-0055-3098.pdf.

NIOSH [2009b]. Approaches to safe nanotechnology: managing the health and safety 

concerns associated with engineered nanomaterials. 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. 2009-125, 

http://www.cdc.gov/niosh/docs/2009-125/pdfs/2009-125.pdf.

NIOSH [2010]. 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. 2010-168c, 

http://www.cdc.gov/niosh/npg/.

NIOSH [2014a]. Evaluation of occupational exposures at an electronic scrap recycling 

facility. By Ceballos D, Chen L, Page E, Echt A, Oza A, Ramsey J. Cincinnati, OH: U.S. 

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

Health Hazard Evaluation Report 2012-0100-3217, 

https://www.cdc.gov/niosh/hhe/reports/pdfs/2012-0100-3217.pdf.

NIOSH [2014b]. Current strategies for engineering controls in nanomaterial production and 

downstream handling processes. 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. 2014-102, 

http://www.cdc.gov/niosh/docs/2014-102/pdfs/2014-102.pdf.

NIOSH [2014c]. Indoor firing ranges, Cincinnati, OH: U.S. Department of Health and 

Human Services, Centers for Disease Control and Prevention, National Institute for 

Occupational Safety and Health, http://www.cdc.gov/niosh/topics/ranges/. 

NIOSH [2016]. NIOSH manual of analytical methods. Consideration of sampler wall 

deposits, Inclusion of material adhering to internal cassette surfaces during sampling and 

analysis of airborne particles. Cincinnati, OH: U.S. Department of Health and Human 

Services, Centers for Disease Control and Prevention, National Institute for Occupational 

Safety and Health, https://www.cdc.gov/niosh/docs/2003-154/cassetteguidance.html.

NIOSH [2018]. NIOSH manual of analytical methods (NMAM). 5th ed. O’Connor PF, 

Ashley K, eds. 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. 2014-151, http://www.cdc.gov/niosh/nmam.
Health Hazard Evaluation Report 2015-0050-3308 Page 69

National Toxicology Program (NTP) [2009]. Chemical information profile for indium 

tin oxide. Research Triangle Park, NC: U.S. Department of Health and Human Services, 

National Institutes of Health, National Institute of Environmental Health Sciences, National 

Toxicology Program, https://ntp.niehs.nih.gov/ntp/noms/support_docs/ito060309_508.pdf.

National Toxicology Program (NTP) [2011]. Report on carcinogens, 12th ed. Research 

Triangle Park, NC: U.S. Department of Health and Human Services, National Institutes of 

Health, National Institute of Environmental Health Sciences, National Toxicology Program, 

http://ntp.niehs.nih.gov/ntp/roc/twelfth/profiles/Lead.pdf. 

National Toxicology Program (NTP) [2012]. Monograph on the health effects of lowlevel lead. Research Triangle Park, NC: U.S. Department of Health and Human Services, 

National Institutes of Health, National Institute of Environmental Health Sciences, National 

Toxicology Program, 

https://ntp.niehs.nih.gov/ntp/ohat/lead/final/monographhealtheffectslowlevellead_

newissn_508.pdf.

Nomeir AA, Kato S, Matthews HB [1981]. The metabolism and disposition of 

tris(1,3-dichloro-2-propyl)phosphate (Fyrol FR-2) in the rat. Toxicol Appl Pharmacol 

57(3):401–413, https://doi.org/10.1016/0041-008X(81)90238-6.

OSHA [2003]. Standard interpretation letter–lead standard 29 CFR 1926.62 (i)(2)(ii),

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_

id=25617.

Ospina M, Jayatilaka N, Wong L, Restrepo P, Calafat A [2018]. Exposure to organophosphate 

flame retardant chemicals in the U.S. general population: data from the 2013–2014 National 

Health and Nutrition Examination Survey. Environ Int 110(2018):32–41, 

http://dx.doi.org/10.1016/j.envint.2017.10.001.

Petropoulou SS, Petreas M, Park JS [2016]. Analytical methodology using ion-pair liquid 

chromatography-tandem mass spectrometry for the determination of four di-ester metabolites 

of organophosphate flame retardants in California human urine. J Chromatogr A 1434:70–80, 

http://dx.doi.org/10.1016/j.chroma.2016.01.020.

Pettersson-Julander A, van Bavel B, Engwall M, Westberg H [2004]. Personal air sampling 

and analysis of polybrominated diphenyl ethers and other bromine containing compounds at 

an electronic recycling facility in Sweden. J Environ Monit 6(11):874–880, 

http://dx.doi.org/10.1039/B408381D.

Preston EV, McClean MD, Claus Henn B, Stapleton HM, Braverman LE, Pearce EN, Makey 

CM, Webster TF [2017]. Associations between urinary diphenyl phosphate and thyroid 

function. Environ Int 101:158–164, http://dx.doi.ord/10.1016/j.envint.2017.01.020.

Proctor NH, Hughes JP, Fischmann ML [1991]. Chemical hazards of the worplace, 3rd ed. 

New York: Van Nostrand Reinhold.
Page 70 Health Hazard Evaluation Report 2015-0050-3308

Rosenberg C, Hämeilä M, Tornaeus J, Säkkinen K, Puttonen K, Korpi A, Kiilunen M, 

Linnainmaa M, Hesso A [2011]. Exposure to flame retardants in electronics recycling sites. 

Ann Occup Hyg 55(6):658–665, http://dx.doi.org/10.1093/annhyg/mer033.

Schreder ED, Uding N, La Guardia MJ [2016]. Inhalation a significant exposure route for 

chlorinated organophosphate flame retardants. Chemosphere 150:499–504, 

http://dx.doi.org/10.1016/j.chemosphere.2015.11.084.

Schubauer-Berigan MK, Deddens JA, Couch JR, Petersen MR [2010]. Risk of lung cancer 

associated with quantitative beryllium exposure metrics within an occupational cohort. 

Occup Environ Med 68(5):354–360, http://dx.doi.org/10.1136/oem.2010.056515.

Schwartz BS, Hu H [2007]. Adult lead exposure: time for change. Environ Health Perspect 

115(3):451–454, http://dx.doi.org/10.1289/ehp.9782. 

Schwartz BS, Stewart WF [2007]. Lead and cognitive function in adults: a question and 

answers approach to a review of the evidence for cause, treatment, and prevention. Int Rev 

Psychiatry 19(6):671–692, http://dx.doi.org/10.1080/09540260701797936.

Siegel JD, Rhinehart E, Jackson M, Chiarello L, Healthcare Infection Control Practices Advisory 

Committee [2007]. Guideline for isolation precautions: preventing transmission of infectious 

agents in healthcare settings, http://www.cdc.gov/hicpac/pdf/isolation/Isolation2007.pdf. 

Sjodin A, Hagmar L, Klasson-Wehler E, Kronholm-Diab K, Jakobsson E, Bergman A [1999]. 

Flame retardant exposure: polybrominated diphenyl ethers in blood from Swedish workers. 

Environ Health Perspect 107(8):643–648, http://dx.doi.org/10.1289/ehp.99107643.

Sjodin A, Carlsson H, Thuresson K, Sjolin S, Bergman A, Ostman C [2001]. Flame retardants 

in indoor air at an electronics recycling plant and at other work environments. Environ Sci 

Technol 35(3):448–454, http://dx.doi.org/10.1021/es000077n.

Sjodin A, Wong LY, Jones RS, Park A, Zhang Y, Hodge C, Dipietro E, McClure C, Turner 

W, Needham LL, Patterson Jr DG [2008]. Serum concentrations of polybrominated diphenyl 

ethers (PBDEs) and polybrominated biphenyl (PBB) in the United States population: 2003–

2004. Environ Sci Technol 42(4):1377–1384, http://dx.doi.org/10.1021/es702451p.

Stapleton HM, Dodder NG [2008]. Photodegradation of decabromodiphenyl ether in house dust 

by natural sunlight. Environ Toxicol Chem 27(2):306–312, http://dx.doi.org/10.1897/07-301R.1.

Stapleton HM, Klosterhaus S, Keller A, Ferguson PL, van Bergen S, Cooper E, Webster T, 

Blum A [2011]. Identification of flame retardants in polyurethane foam collected from baby 

products. Environ Sci Technol 45(12):5323–5331, http://dx.doi.org/10.1021/es2007462.

Stapleton HM, Misenheimer J, Hoffman K, Webster TF [2014]. Flame retardant associations 

between children’s handwipes and house dust. Chemosphere 116:54–60, 

http://dx.doi.org/10.1016/j.chemosphere.2013.12.100.

Stauber JL, Florence TM, Gulson B, Dale L [1994]. Percutaneous absorption of inorganic lead 

compounds. Sci Total Environ 145(1–2):55–70, https://doi.org/10.1016/0048-9697(94)90297-6.
Health Hazard Evaluation Report 2015-0050-3308 Page 71

Sun CC, Wong TT, Hwang YH, Chao KY, Jee SH, Wang JD [2002]. Percutaneous absorption 

of inorganic lead compounds. Am Ind Hyg Assoc J 63(5):641–646, 

https://doi.org/10.1080/15428110208984751.

Thuresson K, Bergman K, Rothenbacher K, Herrmann T, Sjölin S, Hagmar L, Päpke O, Jakobsson 

K [2006a]. Polybrominated diphenyl ether exposure to electronics recycling workers--a follow up 

study. Chemosphere 64(11):1855–1861, https://doi.org/10.1016/j.chemosphere.2006.01.055.

Thuresson K, Hoglund P, Hagmar L, Sjodin A, Bergman A, Jakobsson K [2006b]. Apparent 

half-lives of hepta- to decabrominated diphenyl ethers in human serum as determined in 

occupationally exposed workers. Environ Health Perspect 114(2):176–181, 

https://dx.doi.org/10.1289/ehp.8350.

TSI Incorporated [2012]. Hand-held condensation particle counter model 3007. Shoreview, 

MN: TSI Incorporated.

TSI Incorporated [2014]. DustTrakTM DRX aerosol monitor model 8533/8534/8533EP 

operation and service manual. Shoreview, MN: TSI Incorporated.

van der Veen I, de Boer J [2012]. Phosphorus flame retardants: properties, production, 

environmental occurrence, toxicity and analysis. Chemosphere 88(10):1119–1153, 

http://dx.doi.org/10.1016/j.chemosphere.2012.03.067.

Vincoli JW [1997]. Risk management for hazardous chemicals. Boca Raton, FL: CRC Press.

Watkins DJ, McClean MD, Fraser AJ, Weinberg J, Stapleton HM, Sjödin A, Webster TF 

[2011]. Exposure to PBDEs in the office environment: evaluating the relationships between 

dust, handwipes, and serum. Environ Health Perspect 19(9):1247–1252, 

http://dx.doi.org/10.1289/ehp.1003271.

Watkins DJ, McClean MD, Fraser AJ, Weinberg J, Stapleton HM, Webster TF [2013]. 

Associations between PBDEs in office air, dust, and surface wipes. Environ Int 59:124–132, 

http://dx.doi.org/10.1016/j.envint.2013.06.001. 

WHO [1992]. Environmental health criteria 134. Cadmium. Geneva, Switzerland: World 

Health Organization, http://www.inchem.org/documents/ehc/ehc/ehc134.htm.
Page 72 Health Hazard Evaluation Report 2015-0050-3308

Keywords: North American Industry Classification System (NAICS) 423930 (Recyclable 

Material Merchant Wholesalers), Ohio, Electronics Recycling, E-Scrap, E-Waste Flame 

Retardants, Lead, Cadmium, Indium, Nanoparticles
Health Hazard Evaluation Report 2015-0050-3308 Page 73

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

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

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

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

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

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

Disclaimer

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

evaluated and may not be applicable to other workplaces.

Mention of any company or product in this report does not constitute endorsement by NIOSH.

Citations to Web sites external to NIOSH do not constitute NIOSH endorsement of the 

sponsoring organizations or their programs or products. NIOSH is not responsible for the 

content of these Web sites. All Web addresses referenced in this document were accessible as of 

the publication date.

Acknowledgments

Analytical Support: Maxxam Analytics

Desktop Publisher: Shawna Watts 

Editor: Ellen Galloway 

Industrial Hygiene Field Assistance: Kevin Dunn, Jonathan Slone 

Logistics: Donnie Booher, Kevin Moore

Medical Field Assistance: Deborah Sammons, Barbara MacKenzie, Christine Toennis

Biomonitoring Data: Nayana Jayatilaka, Richard Jones

We received support for this study from NIOSH as part of its National Occupational 

Research Agenda activities.

Availability of Report

Copies of this report have been sent to the employer and employees at the facility. 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 for this report:

NIOSH [2018]. Evaluation of exposure to metals, flame retardants, and nanomaterials 

at an electronics recycling company. By Beaucham CC, Ceballos D, Page EH, Mueller 

C, Calafat A, Sjodin A, Ospina M, La Guardia M, Glassford E. Cincinnati, OH: U.S. 

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

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

2015-0050-3308, https://www.cdc.gov/niosh/hhe/reports/pdfs/2015-0050-3308.pdf.
To receive NIOSH documents or more information about 

occupational safety and health topics, please contact NIOSH:

Telephone: 1–800–CDC–INFO (1–800–232–4636)

TTY: 1–888–232–6348

CDC INFO: www.cdc.gov/info

or visit the NIOSH Web site at www.cdc.gov/niosh

For a monthly update on news at NIOSH, subscribe to 

NIOSH eNews by visiting www.cdc.gov/niosh/eNews.

Delivering on the Nation’s promise:

Promoting productive workplaces through safety and health research