Evaluation of Metal 

and Carbon Monoxide 

Exposures During Steel 

Slab Cutting and Slitting – 

Indiana 

Gregory Burr, CIH

Judith Eisenberg, MD, MS

SeungHee Jang, MPH

Health Hazard Evaluation Report

HETA 2008-0091-3118

December 2010

DEPARTMENT OF HEALTH AND HUMAN SERVICES

Centers for Disease Control and Prevention

Workplace

Safety and Health

 National Institute for Occupational 

Safety and Health

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

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

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

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

for a period of 30 calendar days at or near 

the workplace(s) of affected employees. The 

employer shall take steps to insure that the 

posted determinations are not altered, defaced, 

or covered by other material during such 

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

amended at 45 FR 2653, January 14, 1980].
Health Hazard Evaluation Report 2008-0091-3118 Page i

Appendix

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

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

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

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

Assessment.........................................................................2

Results.................................................................................3

Discussion ...........................................................................8

Conclusions.........................................................................9

Recommendations.............................................................10

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

Contents

Occupational Exposure Limits and Health Effects.............12

Acknowledgments Acknowledgments and Availability of Report.....................15
Page ii Health Hazard Evaluation Report 2008-0091-3118

μg/m3 Micrograms per cubic meter

ACGIH® American Conference of Governmental Industrial Hygienists

CO Carbon monoxide

CFR Code of Federal Regulations

GA General area

HHE Health hazard evaluation

Lpm Liters per minute

mL Milliliter

MDC Minimum detectable concentration

MQC Minimum quantifiable concentration

NIOSH National Institute for Occupational Safety and Health

NAICS North American Industry Classification System

OEL Occupational exposure limit

OSHA Occupational Safety and Health Administration

PEL Permissible exposure limit

PBZ Personal breathing zone

PPE Personal protective equipment

ppm Parts per million

REL Recommended exposure limit

TLV® Threshold limit value

TWA Time-weighted average

WEEL Workplace environmental exposure limit

Abbreviations
Health Hazard Evaluation Report 2008-0091-3118 Page iii

What NIOSH Did

● We sampled the air for minerals, metals, and carbon 

monoxide in the caster/slitter and shipping areas from April 

3–4, 2008.

● We spoke privately with 22 employees in the No. 1 caster/

slitter area and asked them about their health concerns 

related to their work.

● We checked the ventilation in the shipping shanty, two 

employee break rooms, and the cut-off and slitter pulpits.

What NIOSH Found

● No. 1 caster/slitter employees were not exposed to minerals, 

metals, or carbon monoxide in the air above occupational 

exposure limits.

● Employees reported less dust in the slitter pulpit after 

ventilation was added.

● Sixteen of 22 employees we spoke with did not report workrelated symptoms. Six employees reported work-related 

cough, sore throat, nosebleeds, anxiety, headaches, and eye 

irritation.

● Employees with possible work-related symptoms had not 

reported them to the employer.

● Cough, sore throat, and nosebleeds are consistent with upper 

respiratory irritation due to dust exposure. These symptoms 

are also common in the general population and cannot be 

directly linked to work exposure.

● A voluntary use respirator program was in place for No. 1 

caster/slitter employees. Some employees were seen wearing 

respirators that were visibly dirty.

● The interiors of mill-side and load-side crane cabs were 

dusty even though recent changes had been made to their 

ventilation systems.

What Managers Can Do

● Seal gaps in the mill-side and load-side crane cab enclosures. 

Air intakes and exhausts should also be checked.

● Keep the pipe fitter break room in the caster/slitter area 

under positive pressure (air should flow from the break room 

to the surrounding production area).

The National Institute for 

Occupational Safety and 

Health (NIOSH) received 

a request from the United 

Steelworkers for a health 

hazard evaluation at a 

large Indiana steel mill. 

The union was concerned 

about metal dust and 

fume exposure to 

employees working at the 

No. 1 caster/slitter. Bloody 

nose and dirty nasal 

passages were listed as 

health concerns.

Highlights of the

NIOSH Health

Hazard Evaluation
Page iv Health Hazard Evaluation Report 2008-0091-3118

Highlights of the

NIOSH Health

Hazard Evalution

(continued)

● Encourage cut-off and slitter operators and shippers to do as 

much work as possible inside their pulpits or shanty.

● Enforce proper use and change outs of voluntary use 

respirators.

● Encourage employees to report any health problems that are 

potentially work related.

What Employees Can Do

● Report any health problems that are work related to the 

employer.

● Cut-off and slitter operators and shippers should do as much 

work as possible inside their enclosed pulpits and shanty to 

reduce dust exposure.

● Crane operators should make sure gaps in the cab enclosure 

are sealed and that air filters are installed and working 

properly.

● If you choose to wear an N95 filtering facepiece respirator 

voluntarily when working outside the pulpits or shanty, wear 

it properly. Make sure the respirator fits well, which includes 

your being clean-shaven, and exchange it for a clean one daily 

or sooner if it becomes difficult to breathe through.
Health Hazard Evaluation Report 2008-0091-3118 Page v

In January 2008, NIOSH received an HHE request from the 

United Steelworkers concerning metal dust and fume exposure 

from the semiautomated No. 1 caster/slitter operation at an 

Indiana steel mill. Health concerns listed on the request included 

bloody nose and dirty nasal passages. We met with employer and 

employee representatives and observed work processes, practices, 

and workplace conditions on April 2–4, 2008. We reviewed the 

results of previous environmental sampling conducted by the steel 

mill and held confidential interviews with employees to discuss 

health and workplace concerns. We collected PBZ and GA air 

samples for minerals, metals, and CO and evaluated the ventilation 

systems in the cut-off and slitter pulpits, the shipping shanty, and 

two break rooms.

The PBZ and GA air samples were analyzed for 31 minerals 

and metals. Airborne particulate in the No. 1 caster/slitter and 

shipping areas was primarily iron oxide, but other metals such as 

copper, manganese, molybdenum, and nickel were also present in 

measurable amounts. Employees’ exposures were below applicable 

OELs, although the iron oxide TWA exposures for the crane 

operators (range: 1900 to 2800 μg/m3) approached or exceeded 

one half of the OSHA PEL and NIOSH REL of 5000 μg/m3. All 

CO concentrations were below the OSHA PEL and NIOSH REL. 

The cut-off and slitter pulpits, the shipping shanty, and the iron 

worker break room were under positive pressure in relation to 

the surrounding production areas. The pulpits, shanty, and break 

rooms were provided with air ducted from outside the building.

Twenty-two of 28 employees scheduled to work on the days of our 

evaluation participated in the confidential medical interviews. 

All but two were male, and the average age was 45 years. Of 22 

employees interviewed, 17 (77%) were either current or former 

smokers. Of the 22 employees interviewed, 16 reported no workrelated symptoms, but many noted having black nasal secretions 

and phlegm. The remaining six employees reported work-related 

symptoms including eye irritation (1), cough (1), sore throat (2), 

nosebleeds (2), anxiety (1), and headache (2). Cough, sore throat, 

and nosebleeds are consistent with upper respiratory irritation 

due to dust exposure. These symptoms are also common in the 

general population and cannot be directly linked to work exposure. 

These six employees had also reported workplace dustiness to their 

supervisors but had not reported their health symptoms to either 

the employer or to the on-site occupational health clinic. However, 

no interviewed employees reported feeling pressured by the 

NIOSH was asked to 

evaluate metal dust 

and fume exposure to 

employees working at the 

No. 1 caster/slitter and 

shipping areas at a steel 

mill. We sampled the air 

and found that employees 

were not exposed to 

minerals, metals, or 

carbon monoxide. The 

symptoms reported by 

some of the employees 

(cough, sore throat, 

and nosebleeds) are 

consistent with upper 

respiratory irritation 

due to dust exposure. 

These symptoms are also 

common in the general 

population and cannot 

be directly linked to work 

exposure. 

Summary
Page vi Health Hazard Evaluation Report 2008-0091-3118

Summary (continued) employer not to report symptoms. Interviewed employees reported 

that there was less dust in the slitter pulpit after the ventilation 

system was improved and that ventilation changes to the crane cabs 

and shipping shanty were less effective than the changes to the 

slitter pulpit in reducing dust. Dust was reported as worse in the 

winter when the doors were closed.

On the basis of this evaluation we recommended sealing gaps in 

the crane cab enclosures and evaluating the fit and effectiveness 

of the air filters installed in the crane cab enclosures. We 

recommended that the cut-off and slitter operators and shippers 

perform as much of their work as possible within their ventilated 

pulpits or shanty. Employees should wear the voluntary use 

respirators properly and replace them at least daily or more often 

if the respirator becomes difficult to breathe through. We also 

recommended that employees report any work-related health 

problems to the on-site occupational health clinic. Additionally, 

because employees were allowed to smoke in the work place, the 

steel mill should implement a smoking cessation program because 

smoking can have many adverse health effects.

Keywords: NAICS 332312 (Fabricated Structural Metal 

Manufacturing), steel mill, dust, fume, metal, iron oxide, carbon 

monoxide, ventilation, bloody nose
Health Hazard Evaluation Report 2008-0091-3118 Page 1

Introduction

NIOSH received an HHE request from the United Steelworkers 

concerning metal dust and fume exposure from the No. 1 caster/

slitter operation at a steel mill in Indiana. The semiautomated 

caster/slitter began operation in 2007 and was the first of its type 

for this steel mill. NIOSH investigators conducted an evaluation 

on April 2–4, 2008. We met with employer and employee 

representatives; observed work processes, practices, and workplace 

conditions; reviewed the results of previous environmental 

sampling conducted by the steel mill; and held confidential 

interviews with affected employees to discuss health and workplace 

concerns. We collected PBZ and GA air samples for minerals, 

metals, and CO and evaluated the ventilation systems in the cutoff and slitter pulpits, the shipping shanty, and two break rooms 

used by iron workers and pipe fitters. An informational letter 

summarizing our activities during this evaluation was sent to the 

company and union in April 2008.

Process Description 

A steel slab of uniform thickness is conveyed from the continuous 

caster to the No. 1 caster/slitter area and is cut to length 

(approximately 40 feet) by an automated oxygen/fuel torch that is 

remotely controlled by the cut-off operator working inside a nearby 

enclosed pulpit. The cut-off operator occasionally leaves the pulpit 

to check the slab cutting or to communicate with nearby crane 

operators. The cut slabs roll to an adjacent table to cool.

Cut slabs are moved from the cooling table to a staging 

(inventory) area by an overhead mill-side crane operator using 

an electromagnet. After inventory, the slabs are moved (again by 

the mill-side crane operator) to one of eight elevated tables where 

they are slit lengthwise.* The slitter operator verifies that the slab 

is positioned correctly on the slitting table and adjusts the laserguided, computer-controlled oxygen/fuel slitting torch. Once 

the torch slitting begins, the slitter operator moves to the next 

slitting table, a process that is repeated throughout the shift. This 

operation is monitored from an enclosed pulpit, but the slitter 

operator may spend approximately 50% of his time outside the 

pulpit to check that the torches are slitting properly and to make 

any needed adjustments. Each slab takes approximately 45 minutes 

to slit, and a maximum of eight slabs can be slit at one time.

The mill-side crane operator moves the slit slabs with an 

electromagnet from the slitting table to a staging (shipping) area. 

* Prior to 2007 slab slitting was performed manually on the mill 

floor.
Page 2 Health Hazard Evaluation Report 2008-0091-3118

Introduction 

(continued)

Assessment

A shipper manually attaches an identification tag to each slab. 

During the shift the shippers perform their work from either inside 

a nearby enclosed shanty or outside the shanty next to the staged 

slabs. In the final step of this process, the slabs are moved from 

the staging area by the mill-side crane operator and positioned for 

shipment. Two enclosed break rooms in the No. 1 caster/slitter 

area are used by iron workers and pipe fitters.

At the time of this evaluation the steel mill had two 8-hour 

production shifts in the No. 1 caster/slitter area (day and evening), 

with 7 to 10 employees per shift. In addition to the mandatory 

requirement of hard hats, safety shoes, hearing protection, and eye 

protection for employees working in this area, the company also 

allowed the voluntary use of N95 filtering facepiece respirators. 

Employees were offered annual physicals and could report any 

health problems to the steel mill’s on-site occupational health 

clinic.

Full-shift PBZ air samples for minerals, metals, and CO were 

collected in the No. 1 caster/slitter operation and shipping area 

over the day and evening shifts on April 3–4, 2008. We sampled 

the cut-off and slitter operators, shippers, and mill-side and 

load-side crane operators. In addition to PBZ air samples, GA 

air samples were collected for minerals and metals in work areas 

adjacent to the No. 1 caster/slitter operation that were frequented 

by maintenance employees.

Air samples were collected at an airflow rate of 2.0 Lpm 

onto 37-millimeter diameter, 0.8-micrometer pore size mixed 

cellulose ester filters contained in plastic cassettes. The samples 

were analyzed using inductively coupled argon plasma-atomic 

emission spectroscopy per NIOSH Method 7303 [NIOSH 

2010]. The analytical method was modified by adding 2.5 mL of 

hydrochloric acid to each sample instead of adding 1.25 mL each 

of concentrated hydrochloric and nitric acid. After heating the 

samples on a hot block, the analytical method was further modified 

by adding 2.5 mL instead of 1.25 mL of nitric acid to each.

The CO concentrations were measured using Toxi Ultra directreading CO detectors (Biosystems, Middletown, Connecticut). 

These detectors use an electrochemical cell to detect CO levels and 

were calibrated on site prior to use. The CO levels were recorded 

in real time at 1-minute intervals; this data set was then used 

to calculate full-shift TWA exposures and peak exposures. The 

detectors are capable of measuring CO levels of 0–1000 ppm; the 

generally accepted accuracy of electrochemical sensors is ± 5% or 
Health Hazard Evaluation Report 2008-0091-3118 Page 3

Assessment (continued) ± 2 ppm, whichever is greater. The appendix titled “Occupational 

Exposure Limits and Health Effects,” contains additional OEL and 

health effect information on iron oxide (the predominant metal 

found in the air samples) and CO.

Ventilation smoke tubes were used to qualitatively evaluate air 

flow patterns in the cut-off and slitter pulpits, the shanty used by 

the shippers, and two employee break rooms. The steel mill had 

recently installed (within 2 weeks of this NIOSH evaluation) rigid 

ductwork to provide outdoor air to the air handling units in the 

cut-off and slitter pulpits, the shipping shanty, and break rooms.

All day shift No. 1 caster/slitter employees and maintenance 

employees primarily assigned to this area were invited to participate 

in confidential medical interviews.

Elements and Carbon Monoxide

The PBZ and GA air samples collected were analyzed for 

aluminum, antimony, arsenic, barium, beryllium, cadmium, 

calcium, chromium, cobalt, copper, iron, lanthanum, lead, lithium, 

magnesium, manganese, molybdenum, nickel, phosphorus, 

potassium, selenium, silver, strontium, tellurium, thallium, tin, 

titanium, vanadium, yttrium, zinc, and zirconium [NIOSH 2010]. 

As shown in Tables 1 and 2, airborne particulate in the caster 

slitter and shipping areas was primarily iron oxide. Although all 

iron oxide exposures were below their OELs, the PBZ exposures 

for the mill-side and load-side crane operators (range: 1900 to 2800 

μg/m3) approached or exceeded one half of the OSHA PEL and 

NIOSH REL of 5000 μg/m3 as an 8-hour TWA.

Results
Page 4 Health Hazard Evaluation Report 2008-0091-3118

Results (continued)

Table 1. Element concentrations in the caster/slitter and shipping areas, day shift, April 3, 2008

Job

Sample 

Time 

(min)

Sample 

Volume 

(L)

Concentration, μg/m3

Cu* Fe* Pb* Mn* Mo* Ni*

PBZ air samples

Slitter Trainee 357 733 1.6 340 ND† 2.7 ND (0.34)‡

Slitter Operator 460 945 1.3 300 ND 2.6 ND ND

Crane Operator, load side 499 1025 15 1900 (0.38) 11 0.78 0.15

Crane Operator, mill side 487 1004 19 2300 (0.50) 11 0.13 0.18

Cut-Off Operator 473 963 (0.30) 42 ND 0.37 ND ND

Shipper, mill side 388 797 1.9 440 6.3 6.4 ND ND

Shipper, load side 406 832 2.8 580 8.8 7.2 ND (0.19)

 GA air samples

Slitter #4, south side 449 875 29 6100 (0.68) 31 3.0 5.0

Slitter #5, south side 511 895 39 9300 (0.82) 46 2.9 5.6

Maintenance, mill side 454 940 6.5 1600 ND 10 0.69 0.90

Maintenance, load side 453 930 3.7 1000 ND 9.2 (0.32) 0.51

MDC 800 0.09 3 0.4 0.06 0.1 0.1

MQC 800 0.30 14 1.3 0.19 0.41 0.34

NIOSH REL 1000 5000 50 1000 10000 15

OSHA PEL 1000 5000 50 5000 15000 1000

*Cu = copper, Fe = iron, Pb = lead, Mn = manganese, Mo = molybdenum, Ni = nickel

†ND = not detected, the concentration was below the MDC

‡ Concentrations between the MDC and MQC are shown in parentheses to acknowledge that there is more uncertainty 

surrounding concentrations below the MQC.

Elements that are not reported above but were measured between the MDC and MQC and below the MDC:

aluminum, ranging from ND (<0.5 μg/m3) to 7.7 μg/m3); antimony, ranging from ND (<0.8 μg/m3) to between the MDC 

and MQC (1.9 μg/m3); arsenic, ranging from (ND (<1 μg/m3 ) to between the MDC and MQC (6.0 μg/m3); barium, 

ranging from ND (<0.04 μg/m3) to 5.2 μg/m3; cadmium, ranging from ND (<0.04 μg/m3) to 0.40 μg/m3; calcium, ranging 

from 12 to 103 μg/m3; chromium, ranging from ND (<0.3 μg/m3) to 3.9 μg/m3; cobalt, ranging from ND (<0.04 μg/m3) to 

1.0 μg/m3; magnesium, ranging from 3.7 to 17 μg/m3; phosphorus, ranging from ND (<3 μg/m3) to between the MDC 

and MQC (13 μg/m3); potassium, ranging from ND (<1 μg/m3) to between the MDC and MQC (4.6 μg/m3); strontium, 

ranging from ND (<0.03 μg/m3) to between the MDC and MQC (0.075 μg/m3); tin, ranging from ND (<0.9 μg/m3) to 9.0 

μg/m3; vanadium, ranging from ND (<0.04 μg/m3) to 0.23 μg/m3; and zinc, ranging from ND (<0.5 μg/m3) to 3.0 μg/m3

Elements that are not reported above and were not detected (below the MDC):

beryllium (<0.03 μg/m3); lanthanum (<0.03 μg/m3); lithium (<0.04 μg/m3); selenium (<3 μg/m3); silver (<0.03 μg/m3); 

thallium (<1 μg/m3); titanium (<3 μg/m3); yttrium (<0.03 μg/m3), and zirconium (<0.1 μg/m3)
Health Hazard Evaluation Report 2008-0091-3118 Page 5

Results (continued)

Table 2. Element concentrations in the caster/slitter and shipping areas, night shift, April 3–4, 2008

Job

Sample 

Time 

(min)

Sample 

Volume 

(L)

Concentration, μg/m3

Cu* Fe* Pb* Mn* Mo* Ni*

PBZ air samples

Slitter Operator 424 869 1.8 840 ND† 7.2 (0.18)‡ (0.18)

Crane Operator, load side Pump failure No sample results

Crane Operator, mill side 467 952 1.8 2800 (0.45) 15 1.2 1.8

Cut-Off Operator 382 776 ND 50 ND 0.42 ND ND

Shipper, load side 429 877 2.1 560 5.2 5.0 (0.22) (0.18)

Shipper, mill side 325 665 1.7 450 1.7 5.2 ND (0.17)

GA air samples

Slitter #4, south side 438 895 17 4800 ND 19 1.6 1.5

Slitter #5, south side 435 875 78 6100 ND 27 1.1 2.4

Maintenance, mill side 427 886 5.4 1800 ND 11 (0.41) 0.41

Maintenance, load side 437 899 2.9 1045 ND 9.4 (0.26) 0.44

MDC 800 0.09 4 0.4 0.06 0.1 0.1

MQC 800 0.15 14 1.3 0.19 0.41 0.33

NIOSH REL

OSHA REL

1000

1000

5000

5000

50

50

1000

5000

10000

15000

15

1000

*Cu = copper, Fe = iron, Pb = lead, Mn = manganese, Mo = molybdenum, Ni = nickel

†ND = not detected, the concentration is below the MDC

‡ Concentrations between the MDC and MQC are shown in parentheses to acknowledge that there is more uncertainty 

surrounding concentrations below the MQC.

Elements that are not reported above but were measured between the MDC and MQC and below the MDC: 

aluminum, ranging from ND (<0.5 μg/m3) to 7.7 μg/m3); antimony, ranging from ND (<0.8 μg/m3) to between the MDC 

and MQC (1.9 μg/m3); arsenic, ranging from (ND (<1 μg/m3 ) to between the MDC and MQC (6.0 μg/m3); barium, 

ranging from ND (<0.04 μg/m3) to 5.2 μg/m3; cadmium, ranging from ND (<0.04 μg/m3) to 0.40 μg/m3; calcium, ranging 

from 12 to 103 μg/m3; chromium, ranging from ND (<0.3 μg/m3) to 3.9 μg/m3; cobalt, ranging from ND (<0.04 μg/m3) to 

1.0 μg/m3; magnesium, ranging from 3.7 to 17 μg/m3; phosphorus, ranging from ND (<3 μg/m3) to between the MDC and 

MQC (13 μg/m3); potassium, ranging from ND (<1 μg/m3) to between the MDC and MQC (4.6 μg/m3); strontium, ranging 

from ND (<0.03 μg/m3) to between the MDC and MQC (0.075 μg/m3); tin, ranging from ND (<0.9 μg/m3) to 9.0 μg/m3; 

vanadium, ranging from ND (<0.04 μg/m3) to 0.23 μg/m3; and zinc, ranging from ND (<0.5 μg/m3) to 3.0 μg/m3

Elements that are not reported above and were not detected (below the MDC): 

beryllium (<0.03 μg/m3); lanthanum (<0.03 μg/m3); lithium (<0.04 μg/m3); selenium (<3 μg/m3); silver (<0.03 μg/m3); 

thallium (<1 μg/m3); titanium (<3 μg/m3); yttrium (<0.03 μg/m3), and zirconium (<0.1 μg/m3)
Page 6 Health Hazard Evaluation Report 2008-0091-3118

Results (continued)

Ventilation 

Ventilation smoke tubes were used to visually evaluate the airflow 

patterns at the employee door(s) leading to the pulpits, shipping 

shanty, and two break rooms in the No. 1 caster/slitter area (Table 4).

The results of the CO sampling are shown in Table 3. All TWA 

concentrations were below the OSHA PEL and NIOSH REL.

Table 3. Carbon monoxide concentrations in the caster/slitter and shipping areas, April 3–4, 2008

Job Sample Time 

(min)

Concentration, ppm

TWA Ceiling

Day Shift

Slitter Trainee 458 3 14

Slitter Operator 464 3 13

Crane Operator, mill side 474 4 9

Crane Operator, load side 532 5 30

Evening Shift 

Slitter Operator 424 4 16

Cut-Off Operator 381 3 13

Crane Operator, mill side 472 5 12

Crane Operator, load side 469 5 24

Shipper, load side 325 7 124

NIOSH REL 35 200

OSHA REL 50 N/A

Table 4. Ventilation assessments in the caster/slitter area, April 3, 2008

Location Comments

Cut-off and

Slight positive pressure* at the door in relation to the surrounding area. slitter pulpits

Shipping shanty

Positive pressure at the top of both pulpit doors and negative pressure† at the 

bottom of each door. The airflow varied when both doors were opened at the 

same time. 

Iron worker break room Positive pressure at the door in relation to the surrounding area.

Pipe fitter break room Negative pressure at the door in relation to the surrounding area.

* Positive pressure means that air flowed from the pulpit, shanty, or break room into the surrounding work area.

† Negative pressure means that air flowed into the shanty or break room from the surrounding work area.
Health Hazard Evaluation Report 2008-0091-3118 Page 7

Results (continued) Medical

Of 28 employees scheduled to work, 22 participated in the 

confidential medical interviews. All but two were male, their average 

age was 45 years, and 17 of 22 (77%) were either current or former 

smokers. Job titles included crane operator, slitter operator, cutoff operator, shipper, and maintenance. The average duration of 

employment in their current job title was 3.3 years, with an average 

duration of employment at this steel mill of 19.5 years.

Of the 22 employees interviewed, 16 (73%) reported no workrelated symptoms. Six reported work-related symptoms including 

eye irritation (1), cough (1), sore throat (2), nosebleeds (2), anxiety 

(1), and headache (2). These six employees had reported workplace 

dustiness to their supervisors but had reported their health symptoms 

to neither the employer nor to the on-site occupational health clinic. 

The six employees did not characterize the black nasal secretions 

and phlegm as “health problems” but considered them more a 

consequence of poor equipment maintenance. This belief was 

shared by many of the remaining 16 employees who denied having 

any work-related health symptoms but noted having black nasal 

secretions and phlegm. No employee reported feeling pressured by 

the employer not to report symptoms to the occupational health 

clinic. The occupational health clinic staff confirmed no clinic visits 

by employees for dust-related health issues.

Interviewed employees described a decrease in dustiness in the slitter 

pulpit after installation of ventilation ductwork to bring outdoor 

air to the pulpit. However, ventilation changes to the mill-side and 

load-side crane cabs and at the shipping shanty were described by 

interviewed employees as ineffective in reducing dustiness. For 

example, mill-side and load-side crane operators reported the air 

quality in their cabs worsened when the new air-conditioning units 

were operating. Employees reported not seeing any improvement 

in the dustiness after the shipper pulpit was placed under positive 

pressure in relation to the surrounding mill. Several shippers noted 

1-inch gaps at the north wall of the shipper shanty.

In general, employees believed that the dustiness in the No. 1 caster/

slitter area was worse in the winter when the doors were closed. 

Several reported increased dustiness because the semiautomated 

slitter operation was on a raised slitting platform to accommodate the 

automated “spiders” that removed accumulated slag under the freshly 

slit slabs.

Because of the dust generated by the No. 1 caster/slitter operation, 

the steel mill allowed employees to use N95 filtering facepiece 

respirators on a voluntary basis. Although all employees were aware of 
Page 8 Health Hazard Evaluation Report 2008-0091-3118

Results (continued) the voluntary use respirator program, only two interviewed employees 

reported using a respirator. One of these employees brought the 

respirator he was currently using to the interview, and the filter was 

visibly dirty.

The production rate in the No. 1 cutter/slitter area during this 

evaluation was slightly above average. Twenty eight steel slabs were 

processed (slit) during the day shift on April 3, 2008, compared to 

an average of 23 for the 5 prior days. Although this evaluation was 

conducted on a cool day, many of the exterior doors were open for 

most of the day shift. Both north end doors were open from the 

beginning of the day shift, while the east and west doors were closed 

at the beginning of the day shift then opened at 9:30 a.m. for the 

remainder of the shift.

Iron oxide was the primary airborne exposure to the cut-off, slitter, 

and crane operators and to the shippers in the No. 1 cutter/slitter 

area. However, no employees were overexposed on the basis the PBZ 

air sample results obtained from this evaluation. Although other 

researchers have found that employees exposed to iron oxide may also 

be exposed to chromium, nickel, and vanadium [Nemery 1990], we 

did not find overexposures to these other metals.

Our air sampling results suggest that the pulpit used by the slitter 

operators (and to a lesser extent the pulpit used by the cut-off 

operator and the shanty used by the shippers) contributed to 

reducing PBZ exposures to iron oxide and other metals. For example, 

three of the four GA air samples collected on the slitter platform 

during slab slitting exceeded the OEL for iron oxide of 5000 μg/

m3, and iron oxide concentrations from GA air samples collected 

in the maintenance areas ranged from 1000 to 1800 μg/m3. In 

comparison, the PBZ exposures for the cut-off and slitter operators 

and the shippers ranged from 42 to 840 μg/m3. The addition of air 

ducted from outside the building to the cut-off and slitter pulpits, the 

shipping shanty, and the iron worker break room likely improved the 

effectiveness of these enclosures in reducing employee exposures by 

maintaining these areas under a positive pressure in relation to the 

surrounding production areas. The one exception that we noted in 

our evaluation was the pipe fitter break room. This room remained 

under negative pressure in relation to the surrounding production 

area despite the addition of air ducted from outside the building.

The mill-side and load-side crane operators had the highest iron oxide 

exposures, with PBZ TWA exposures that ranged from 1900 to 2800 

μg/m3. This was not unexpected considering that (1) these employees 

are situated above the No. 1 caster/slitter operation, (2) the hot metal 

Discussion
Health Hazard Evaluation Report 2008-0091-3118 Page 9

Discussion (continued) dust and fume generated during slab cutting and slitting thermally 

rise to the top of the building, and (3) the crane operators typically 

remain in their cabs for most of their work shift (because of the 

time required to climb from the production floor to the crane). 

Although the mill-side and load-side crane cabs were enclosed and 

air-conditioned, both cabs had visible gaps in their enclosures, 

and crane operators commented in our interviews that they were 

dissatisfied with the effectiveness of the air filtration for their crane 

cabs. Additionally, two of eight crane operators interviewed reported 

work-related symptoms.

Our sampling found no overexposures to iron oxide that would 

require a mandatory respiratory protection program. However, 

employees voluntarily wearing respirators should be aware that they 

may not be receiving the full protection from the respirator if the 

filter is clogged or if the employee has facial hair preventing a good 

seal. We observed both of these situations during this evaluation. If 

employees are concerned by nasal secretions and/or phlegm darkened 

by inhaling particulate, they may choose to wear a respirator when 

they work outside of their shanty, pulpit, or break room.

Most interviewed employees did not report work-related symptoms. 

Six employees had cough, sore throat, and nosebleeds, symptoms 

consistent with upper respiratory irritation due to dust exposure. 

However, these symptoms may also occur in the general population 

and cannot be directly linked to work exposures. The steel mill 

employees did not consider the black nasal secretions and phlegm 

a health problem, and air sampling revealed no iron oxide 

overexposures. Although interviewed employees chose not to report 

work-related symptoms to the occupational health clinic or to 

managers, by following up with the on-site occupational health clinic 

the employees may determine over time whether the symptoms are 

work-related and associated with particulate exposure from the No. 1 

caster/slitter.

Employees working at the No. 1 caster/slitter at this steel mill were 

not exposed to minerals, metals, or carbon monoxide above OELs 

on the days of this HHE. Cough, sore throat, and nosebleeds are 

consistent with upper respiratory irritation due to dust exposure. 

These symptoms are also common in the general population and 

cannot be directly linked to work exposure. However, the black 

nasal secretions and phlegm reported by employees are likely due to 

nonrespirable iron oxide particulate trapped in the nose and upper 

airways. Engineering and administrative controls and the voluntary 

use of respirators may further reduce particulate exposures to No. 1 

caster/slitter employees.

Conclusions
Page 10 Health Hazard Evaluation Report 2008-0091-3118

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

to create a more healthful workplace. We encourage the steel mill to 

use a labor-employer health and safety committee or working group 

to discuss the recommendations in this report and develop an action 

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

the feasibility of our recommendations for the specific situation at 

the steel mill. Our recommendations are based on the hierarchy of 

controls approach that 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/or personal protective equipment may 

be needed.

Engineering Controls 

Engineering controls reduce exposures to employees by removing the 

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

the employee. Engineering controls are very effective at protecting 

employees without placing primary responsibility of implementation 

on the employee.

1. Seal gaps in the mill-side and load-side crane cab enclosures.

2. Evaluate the air intake and exhaust for the crane cab 

enclosures to determine if they are correctly installed and 

functioning properly.

3. Evaluate the fit and effectiveness of the air filter installed in 

both the load-side and mill-side crane cab enclosures.

4. Evaluate the ventilation system for the pipe fitter break room 

in the No. 1 caster/slitter area. This room remained under 

negative pressure in relation to the surrounding production 

area despite the addition of air ducted from outside the 

building.

Administrative Controls 

Administrative controls are employer-dictated work practices and 

policies to reduce or prevent exposures to workplace hazards. 

The effectiveness of administrative changes in work practices for 

controlling workplace hazards is dependent on employer commitment 

and employee acceptance. Regular monitoring and reinforcement 

are necessary to ensure that control policies and procedures are not 

circumvented in the name of convenience or production.

1. Encourage the cut-off and slitter operators to perform as much 

of their work as possible within their respective pulpits.

Recommendations
Health Hazard Evaluation Report 2008-0091-3118 Page 11

Recommendations

(continued) 2. Encourage shippers to conduct as much of their work as 

possible inside their shanty.

3. Encourage employees to report work-related health problems 

to the steel mill’s occupational health clinic. Reporting 

maintenance issues to the employer should not occur in place of 

appropriate medical assessments.

4. Implement a smoking cessation program because smoking can 

have many adverse health effects. Additional information on 

smoking cessation programs can be obtained by calling 1-800-

QUIT NOW (1-800-784-8669) or from the NIOSH Current 

Intelligence Bulletin 54, Environmental Tobacco Smoke in the 

Workplace available at http://www.cdc.gov/niosh/91108_54.

html.

Personal Protective Equipment

PPE is the least effective means for controlling employee exposures. 

Proper use of PPE requires a comprehensive program and calls for a 

high level of employee involvement and commitment to be effective. 

The use of PPE requires the choice of the appropriate equipment to 

reduce the hazard and the development of supporting programs such 

as training, change-out schedules, and medical assessment if needed. 

PPE should not be relied upon as the sole method for limiting 

employee exposures. Rather, PPE should be used until engineering 

and administrative controls can be demonstrated to be effective in 

limiting exposures to acceptable levels.

1. Encourage the proper wearing of voluntary use respirators.

2. Require employees who wear respirators voluntarily to be 

clean shaven in the area of the face seal and to replace their 

respirator when it is visibly clogged or becomes difficult to 

breathe through.

NIOSH [2010]. NIOSH manual of analytical methods (NMAM®). 4th 

ed. Schlecht PC, O’Connor PF, 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 94–113 (August, 1994); 1st Supplement 

Publication 96135, 2nd Supplement Publication 98–119; 3rd 

Supplement 2003–154. [http://www.cdc.gov/niosh/nmam/].

Nemery B [1990]. Metal toxicity and the respiratory tract. Eur Respir 

J 3(2):202–219.

References
Page 12 Health Hazard Evaluation Report 2008-0091-3118

In evaluating the hazards posed by workplace exposures, NIOSH investigators use both mandatory (legally 

enforceable) and recommended OELs for chemical, physical, and biological agents as a guide for making 

recommendations. OELs have been developed by Federal agencies and safety and health organizations to 

prevent the occurrence of adverse health effects from workplace exposures. Generally, OELs suggest levels 

of exposure that most employees may be exposed 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 from 

adverse health effects even if their exposures are maintained below these levels. A small percentage may 

experience adverse health effects because of individual susceptibility, a preexisting medical condition, and/

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

workplace exposures, the general environment, or with medications or personal habits of the employee 

to produce health effects even if the occupational exposures are controlled at the level set by the exposure 

limit. Also, some substances can be absorbed by direct contact with the skin and mucous membranes in 

addition to being inhaled, which contributes to the individual’s overall exposure.

Most OELs are expressed as a 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 STEL or ceiling 

values where health effects are caused by exposures over a short period. Unless otherwise noted, the STEL 

is a 15-minute TWA exposure that should not be exceeded at any time during a workday, and the ceiling 

limit is an exposure that 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, while others are 

recommendations. The U.S. Department of Labor OSHA PELs (29 CFR 1910 [general industry]; 29 

CFR 1926 [construction industry]; and 29 CFR 1917 [maritime industry]) are legal limits enforceable in 

workplaces covered under the Occupational Safety and Health Act. NIOSH RELs are recommendations 

based on a critical review of the scientific and technical information available on a given hazard and the 

adequacy of methods to identify and control the hazard. NIOSH RELs can be found in the NIOSH Pocket 

Guide to Chemical Hazards [NIOSH 2005]. NIOSH also recommends different types of risk management 

practices (e.g., engineering controls, safe work practices, employee education/training, personal protective 

equipment, and exposure and medical monitoring) to minimize the risk of exposure and adverse health 

effects from these hazards. Other OELs that are commonly used and cited in the United States include 

the TLVs recommended by ACGIH, a professional organization, and the WEELs recommended by the 

American Industrial Hygiene Association, another professional organization. The TLVs and WEELs are 

developed by committee members of these associations from a review of the published, peer-reviewed 

literature. They are not consensus standards. ACGIH TLVs 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 2010]. WEELs have been established for some chemicals “when no other legal or 

authoritative limits exist” [AIHA 2010].

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

both legal and recommended limits. Since 2006, the Berufsgenossenschaftliches Institut für Arbeitsschutz 

(German Institute for Occupational Safety and Health) has maintained a database of international 

OELs from European Union member states, Canada (Québec), Japan, Switzerland, and the United 

States available at http://www.dguv.de/bgia/en/gestis/limit_values/index.jsp. The database contains 

international limits for over 1250 hazardous substances and is updated annually.

Appendix: Occupational Exposure Limits and Health Effects
Health Hazard Evaluation Report 2008-0091-3118 Page 13

Appendix: Occupational Exposure Limits and Health Effects (continued)

Employers should understand that not all hazardous chemicals have specific OSHA PELs, and for some 

agents the legally enforceable and recommended limits may not reflect current health-based information. 

However, an employer is still required by OSHA to protect its employees from hazards even in the absence 

of a specific OSHA PEL. 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))]. Thus, NIOSH investigators encourage 

employers to make use of other OELs when making risk assessment and risk management decisions to 

best protect the health of their employees. NIOSH investigators also encourage the use of the traditional 

hierarchy of controls approach to eliminate or minimize identified 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) 

personal protective equipment (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 that focuses resources on exposure controls by describing how a risk 

needs to 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 the OELs, when available.

Iron Oxide 

The predominant metal measured in the dust and fume generated by the No. 1 caster/slitter area was iron 

oxide, although all exposures were below OELs. Acute (short-term) health effects may occur immediately 

or shortly after exposure to iron oxide and include a flu-like illness with symptoms of metallic taste, fever 

and chills, aches, chest tightness, and cough. Over longer exposure periods, iron oxide fume or dust can 

cause a benign pneumoconiosis called siderosis. With this condition, dust deposition casts a shadow in 

an x-ray of the lung but does not damage the lung. This is usually not seen by x-ray before 6 to 10 years 

of exposure [Hathaway et al. 2004]. In a study of 25 welders exposed to iron oxide fume concentrations 

ranging from 650 to 47,000 μg/m3, approximately one third developed symptoms consistent with siderosis 

[Kleinfeld et al. 1969].

Carbon Monoxide 

A colorless, odorless, tasteless gas, CO can be a product of the incomplete combustion of organic 

compounds. It combines with hemoglobin and interferes with the oxygen-carrying capacity of blood. 

Symptoms of overexposure include headache, drowsiness, and dizziness. Symptoms following much 

higher CO exposures than were measured at this steel mill include nausea, vomiting, collapse, myocardial 

ischemia, and death [Hathaway et al. 2004]. The NIOSH REL for CO is 35 ppm for up to an 8-hour 

TWA. NIOSH also recommends a ceiling limit of 200 ppm that should not be exceeded at any time 

during the workday [NIOSH 2005]. The OSHA PEL for CO is 50 ppm for an 8-hour TWA, and the 

ACGIH TLV for CO is 25 ppm as an 8-hour TWA [29 CFR 1910.1000; ACGIH 2010].
Page 14 Health Hazard Evaluation Report 2008-0091-3118

Appendix: Occupational Exposure Limits and Health Effects (continued)

References

ACGIH [2010]. 2010 TLVs® and BEIs®: threshold limit values for chemical substances and physical 

agents and biological exposure indices. Cincinnati, OH: American Conference of Governmental 

Industrial Hygienists.

AIHA [2010]. AIHA 2010 Emergency response planning guidelines (ERPG) & workplace environmental 

exposure levels (WEEL) handbook. Fairfax, VA: American Industrial Hygiene Association.

CFR. Code of Federal Regulations. Washington, DC: U.S. Government Printing Office, Office of the 

Federal Register.

Hathaway GJ, Proctor NH [2004]. Chemical hazards of the workplace, 5th ed. New York: Van Nostrand 

Reinhold.

Kleinfeld M, Messite J, Kooyman O, Shapiro J [1969]. Welders’ siderosis. Arch Environ Health 19(1):70–

73.

NIOSH [2005]. NIOSH pocket guide to chemical hazards. Cincinnati, OH: U.S. Department of Health 

and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational 

Safety and Health, DHHS (NIOSH) Publication No. 2005-149. [http://www.cdc.gov/niosh/npg/]. Date 

accessed: September 2010.
Health Hazard Evaluation Report 2008-0091-3118 Page 15

Acknowledgments and

Availability of Report

The Hazard Evaluations and Technical Assistance Branch 

(HETAB) of the National Institute for Occupational Safety and 

Health (NIOSH) conducts field investigations of possible health 

hazards in the workplace. These investigations are conducted under 

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

Health Administration (OSHA) Act of 1970, 29 U.S.C. 669(a)

(6) which authorizes the Secretary of Health and Human Services, 

following a written request from any employer or authorized 

representative of employees, to determine whether any substance 

normally found in the place of employment has potentially toxic 

effects in such concentrations as used or found. HETAB also 

provides, upon request, technical and consultative assistance to 

federal, state, and local agencies; labor; industry; and other groups 

or individuals to control occupational health hazards and to 

prevent related trauma and disease.

The findings and conclusions in this report are those of the 

authors and do not necessarily represent the views of NIOSH. 

Mention of any company or product does not constitute 

endorsement by NIOSH. In addition, citations to websites 

external to NIOSH do not constitute NIOSH endorsement of 

the sponsoring organizations or their programs or products. 

Furthermore, NIOSH is not responsible for the content of these 

websites. All Web addresses referenced in this document were 

accessible as of the publication date.

This report was prepared by Gregory Burr and Judith Eisenberg 

of HETAB, Division of Surveillance, Hazard Evaluations and 

Field Studies, and SeungHee Jang, a guest researcher. Industrial 

hygiene field assistance was provided by Donald Booher and Karl 

Feldmann. Analytical support was provided by Bureau Veritas 

North America. Health communication assistance was provided 

by Stefanie Evans. Editorial assistance was provided by Ellen 

Galloway. Desktop publishing was performed by Robin Smith.

Copies of this report have been sent to employee and employer 

representatives at the steel mill, the state health department, and 

the OSHA Regional Office. This report is not copyrighted and 

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

at http://www.cdc.gov/niosh/hhe. Copies may be purchased from 

the National Technical Information Service at 5825 Port Royal 

Road, Springfield, Virginia 22161.
Below is a recommended citation for this report:

NIOSH [2010]. Health hazard evaluation report: exposures to metals and carbon 

monoxide during the cutting and slitting of steel slabs – Indiana. By Burr G, 

Eisenberg J, Jang S. Cincinnati, OH: Department of Health and Human Services, 

Centers for Disease Control and Prevention, National Institute for Occupational 

Safety and Health, NIOSH HETA No. 2008-0091-3118.

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