This presentation provides an overview of control banding (CB), a method for determining control measures for nanoparticles in laboratories. CB involves assigning hazards to exposure "bands" and recommending controls. The authors discuss how CB has been applied at Oak Ridge National Laboratory's Center for Nanophase Materials Sciences, including developing a risk assessment process using CB. Research studies show CB can effectively control exposures, though some hazard bands may require narrower safety margins. The authors propose using initial CB assignments and exposure validation to determine a process's control status, allowing continued operation if sufficiently controlled.

1. Applying control banding in the
determination of control
measures in laboratories using
nanoparticles
Scott Hollenbeck, John Jankovic, Randy Ogle
Center for Nanophase Materials Sciences,
Oak Ridge National Laboratory
The 234th ACS National Meeting,
Boston, MA, August 21, 2007

2. This presentation:
• Overview of basics of Control Banding
• How Control Banding has been applied
to Operations at the Center for
Nanophase Materials Sciences
• Examples of other uses of Control
Banding in the R&D Environment.

3. Control Banding
Control Banding - increased national and international
attention
– as a practical approach to controlling hazardous agents in a
changing world;
– an approach complementary to the traditional methods of air
sampling and analysis.
– Provides a formal process for incorporating professional
judgment and monitoring.
• The concept - initially developed by the pharmaceutical
industry and later adapted for use by small businesses
and developing countries, an approach that was
appealing to many large industries involving chemical
manufacture.
• NIOSH leads U.S. efforts

4. “Control Banding 101”, NIOSH
http://www.cdc.gov/niosh/topics/ctrlbanding/
• Control banding - a process in which a single
control technology is applied to one range or
band of exposures to a chemical (such as
1−10 mg/m3) that falls within a given hazard
group (such as skin and eye irritants or
severely irritating and corrosive).
• Four main control bands have
been developed for exposure
to chemicals by inhalation

5. “Control Banding 101”, NIOSH cont.
• The most developed CB model for control banding has been
established by the Health and Safety Executive (HSE) of the
United Kingdom.
– http://www.coshh-essentials.org.uk/
• “Easy & qualitative”, First applied to dangerous
chemicals, chemical mixtures, and fumes.
• Emphasizes the controls needed to prevent
hazardous substances from causing harm to people
at work.
• The greater the potential for harm, the greater the
degree of control needed to manage the situation and
make the risk “acceptable.”

6. CB can be applied to categories of chemicals or
their mechanism of toxicity (Table 1 =Inhalation)
Application can be prospective, based on
anticipated exposures; or retrospective based on
measured exposures; and should be periodically
be re-evaluated
From NIOSH

7. Does control banding work?
YES
• The German authority (Bundesanstalt für
Arbeitsschutz und Arbeitsmedizin - BAuA) evaluated
the system based on about 1,000 personal
measurements from field studies in 18 industrial
applications. They found that for solids (dusts and
powders) and medium-scale use (liter quantities) of
liquids, exposures were within the range predicted by
the CB process.
• A study of another control banding tool, the
International Labor Organization (ILO) Toolkit, was
conducted in the United States. The study found
small safety margins for the hazard bands that
included high-potency chemicals.

8. Design and Application of Controls Center for
Nanophase Materials Sciences (CNMS)
• CNMS Laboratories, designed to provide high level of control
• Designed for nanotechnology R&D hazards
• For normal R&D operations the goal is to achieve a control status
of 2 or less

9. CNMS method for CB in
prospect
• Research Safety Summary (RSS)
process, flag priority chems.
• At project planning, do CB (or other
hazard analysis) and determine need
for IH monitoring.
• Document in RSS, IH handles informing
employees

10. A Conceptual Idea for Conducting Exposure Assessment as
Part of the CNMS Work Control Process Using Control
Banding to Achieve a Desired Control Status
WORK CONTROL
CONTROL
BANDS
EXPOSURE
EXPOSURE
ANALYSIS
CONTROL

11. A Control Band (CB) designation reflects a belief about the level of
control for a particular process. Validation of the process’s CB
designation determines the actual control status (CS).
CS (0)
No Exposure Potential CB(0)
CS (1) Remote (<< 10% OEL) CB (1)
CS (2) Highly unlikely (< 10% OEL) CB (2)
CS (3) Unlikely (10% < 50% OEL) CB (3)
CS (4) Possible (50% < 100% OEL) CB (4)
Likely (100% + OEL or Unk) CB (5)
CS (5)
Assignment of a CB of 3 or less
Validation as a CS of 3 or less permits start-up and interim
permits continued operation of a operation of a process under
process.
surveillance.

12. The initial CB designation may be assigned on the basis of process
knowledge, exposure data from a similar exposure group/task, modeling,
or a combination thereof.
Belief (exp
potential +
toxicity)
Belief (process
knowledge,
exposure data,
modeling)
Add to specified controls to
achieve a CB designation of 3 or
lower.
Specified Set
of Controls
Control Band
Assignment

13. Once a control band is validated it
Initial represents the control status of the
Control Band operation. Only a CS of 3 or lower is
Assignment acceptable for routine process
(0 – 3) operation. The control status is
reevaluated on a periodic basis
commensurate with the CS level.
Feedback
Validate
Control
Band
CB becomes
Selection Control Status.
Document and
Determine
Reevaluation
Schedule

14. Developing belief about a process/activity based on:
Sampling data Cutting and Cold Forming Cadmium Sheet Metal
ORNL bldg. 7012 sheet metal working (1991-1995)
Date Sample Time Cadmium TWA Cnct’n. Sheets of cadmium were sheared,
(min) (µ g) (µ g/M3)
bent, and rolled to specified sizes
7/26/91 176 ND <1.1
and shapes for use as shielding in
7/26/91 165 ND <1.1 HFIR fuel storage containers. Six
8/21/91 440 ND <1.1 (approx 2' x 4') sheets of cadmium
8/21/91 400 ND <1.1 metal were cut and formed using a
1/11/95 400 ND <1.1 sheet metal shear and a hand
1/11/95 400 ND <1.1
operated break. Breathing zone
exposure monitoring was conducted
Detection limit for Cd was approximately 1 µ g
during this activity.
Assign a CB of 1

15. Developing belief about a process/activity based on:
Process Cutting and Cold Forming Cadmium Sheet Metal
Knowledge is not a likely mechanism to produce cadmium
fume or aerosolize respirable particulates
Assigned CB activity exposure
1 cutting 5% of the exposure limit
1 Bending/shaping <1% of the exposure limit
1 installing <1% of the exposure limit

16. Selection of initial control band (process knowledge and prior
monitoring)
Bayesian analysis of the
sampling data combined
with professional judgment
suggests the control band.
Control Status determination drives
additional assessment
Control Status 1 calls for:
• samples per sampling cycle
2
• 4 month sampling interval
2
• -10% of SEG/SET per cycle
5
• xposures < 10% of OEL = no change
e
in control status

17. EXAMPLE
Decision Probability
Prior Initial Process knowledge
1
0.8
0.6 Control Band and monitoring from
0.6
0.4
0.2
0.14
Assignment similar ops is used to
0.04
(1)
0.02
0.2
0 assign an initial CB
0 1 2 3 4
Exposure Rating
Decision Probability
Previous monitoring of process indicates CB as 1-2 Likelihood
1 0.677
location activity time job 8 h 2d average % of 0.8
(min) concentration AL 0.6 0.315
0.4
0.006
employee # 922470 cutting 290 1.72 gCd/m3 0.51 gCd/m3 2 0.2
0.001 0.000
0
employee # 924275 installing 245 no Cd detected <0.10gCd/m3 <0.4 0 1 2 3 4
Exposure Rating
on wall inside tank installing 516 no Cd detected < 0.14 gCd/m3 <0.6
Decision Probability
Posterior
0.901
1
0.8
0.6
0.4 0.098
0.000 0.001 0
0.2
0
0 1 2 3 4
CB 1 becomes CS 1
Exposure Rating
+
Sampling combined with
process knowledge verifies
CB 1 designation

18. Process control band validation feeds back into data
bases ensuring initial designations reflect actual work
places and practices.

19. For future use from the book of control bands:
Manual Cutting and Cold Forming Cadmium
Control Band Sheet Metal is not a likely mechanism to produce
1 cadmium fume or aerosolize respirable
particulates
Decision Probability
Posterior
0.901
1
0.8
0.6
0.4 0.098
0.000 0.001 0
0.2
0
0 1 2 3 4
Exposure Rating
Controls flow both into and from control band designation
 AZCOM is required in the JHA process.
H
 nitial monitoring is not required for the planned operation.
I
 et wiping the cadmium sheets before handling is desirable but not required.
W
 espiratory protection is not required for the planned operation.
R
 ersonal hygiene and the use of gloves (cotton is acceptable)
P
 and washing before eating or smoking.
H
 rovision of company clothes or coveralls is desirable but not required.
P
Note: Conclusions are based on the assumption that the task to be preformed will involve cutting with shears and cold
forming. Any activities that might abrade or otherwise produce cadmium particles which could become airborne are
outside the scope of this assessment.

20. Two CB examples, from the
CNMS
• First example is a polymer processing
system and determining if CB/Controls
are sufficient.
• Second, is application of CB to carbon
nanotube synthesis

21. Similar Exposure Polymer Collection using solvent systems in fully
Group or Task enclosed process system. Minimal personnel
Control Band 0
(exposure belief < < OEL)
contact during fills and decanting. System and
work takes place in laboratory hood.
General Process Description: Polymers are formed in an enclosed system. Various
solvents contained in the same system are used to separate reacted polymeric
material. The system is opened for filling/recharge, final collection of polymer, and
disposal of spent solvents. Skin/eye contact with solvents is possible during
solvent transfer steps.
Other possible hazards include glass apparatus manipulations involving cutting
and heating with open flame torch.
Solvent exposures in breathing zone are expected to be << 10% of the OEL as task
concentrations without time weighting.

22. Monitoring to validate control band designation and associated controls.
Table 1. Results of air monitoring
location activity time job concentration % of AL
(min)
Researcher BZ standing at hood face- Monitoring/adjusting 5 ND (<0.1 total VOC) ND
arms occasionally inside hood opening. apparatus
Researcher BZ standing at hood face – Opening glass vessel <5 ND (<0.1 total VOC) ND
head occasionally inside plane of hood
opening.
Researcher BZ standing at hood face– Pouring off solvent <5 ND (<0.1 total VOC) ND
head occasionally inside plane of hood
Decision Probability
Decision Probability
Decision Probability
opening.
Prior Likelihood
0.945 0.988
Posterior
1 1 1
0.6
0.8 0.8 0.8
0.6 0.6 0.6
0.2 0.15
0.4 0.4 0.4
0.04 0.01 0 0 0.038 0.017 0 0 0.01 0.001
0.2 0.2 0.2
0 0 0
0 1 2 3 4 0 1 2 3 4 0 1 2 3 4
Exposure Rating Exposure Rating Exposure Rating

23. Monitoring to validate control band designation
combined with belief about process control indicates
control band 2 for this task. This change reflects the
low exposure limit (high toxicity) of benzene, and
the high detection limit of the monitoring equipment.
Similar Exposure Polymer Collection using solvent systems in fully
Group or Task enclosed process system. Minimal personnel
Control Band 2
(exposure belief < < OEL)
contact during fills and decanting. System and
work takes place in laboratory hood.
Minimum controls: Hazcom, PPE to prevent skin contact, and general
ventilation. Process enclosure is recommended but not required.
Resample within 24 months / 3 samples / acceptable control demonstrated if
results < 50% or OEL. More sensitive analytical method may allow for reduction
of control band.

24. Carbon Laser Ablation Process
Ambient background outside
clean room (11,000 p/cc)
Moving into
clean room
Clean room background (25 p/cc)

25. Industrial Hygiene Controls
HEPA vacuum used to move all nano
material from quartz tube into collection
chamber.
Collection chamber removed, ends
covered – highest potential for employee
exposure during this step.
TWA = 120 particles/cc
530 p/cc limit
(OSHA limit for graphite)
Justification described
in corresponding poster.

26. Industrial Hygiene Controls
Harvesting nano materials by enclosing
collection chamber in bag and working in
hood
Overall process TWA = 310 p/cc
Traditional industrial hygiene controls
(clean room under HEPA filtration, local
exhaust ventilation, process enclosure,
HEPA vacuum) effectively control
inhalation exposure.

27. Hazard Assessment
Nano material
created is larger
than 100 nm
Therefore, majority of material
is deposited in head airways
rather than penetrating deep
into the lungs.

28. Ensuring Exposure Control for a New Process
 nitial hazard assessment initiated in research safety summary –
I
a document created jointly with researchers and occupational
health professionals that describes process, risks, and controls
 preliminary control band is assigned based on similar task
A
group
 ontrol bands incorporate requisite controls based on
C
toxicity, exposure potential, monitoring capability, process
stability, and professional judgment
 ontrol band designation is validated by process monitoring and
C
changed as appropriate
 alidated control band incorporates air sampling at requisite
V
resample frequency to ensure continued process control

29. Similar Laser ablation nano particle generation
Exposure
& harvesting
Group or
Task Control Band 2
Decision Probability
Decision Probability
Professional judgment Process evaluation
Likelihood
Prior 1
0.8 0.52 0.48
+
1
0.6 0.6
0.8
0.4
0.6 0 0 0
0.17 0.17 0.2
0.4
0.03 0.03 0
0.2 0 1 2 3 4
0 Exposure Rating
0 1 2 3 4
Exposure Rating Decision Probability
combined
Posterior
0.765
1
0.8
0.6
0.235
0.4
0 0 0
0.2
0
0 1 2 3 4
Exposure Rating

30. Summary for laser ablation
• rocess is controlled using existing methods (clean room, HEPA
P
vacuum, enclosure, local exhaust ventilation).
• nhalation hazard is low for agglomerated particulate as size is less
I
than 100 nm; therefore, does not penetrate into lungs.
• perational exposure limit (530 p/cc) is protective and achievable.
O
• onitoring results combined with professional judgment using
M
Bayesian techniques confirm control band 2 is justified for operations
whenever controls as specified are implemented.
• esample every year or with any change in process by performing a
R
spot check (three breathing zone measurements). If median is less
than or equal to 265 p/cc process is considered to continue as well
controlled.

31. Conclusions
• Efficient and effective method for hazard
analysis in the R&D environment
• Provides a formal process for incorporating
pre- and post judgment regarding a task
• Ranks tasks based on degree of hazard
control
• Provides a method of conducting and
documenting hazard assessments