Applying control banding in the
   determination of control
measures in laboratories using
        nanoparticles
    Scott...
This presentation:
•  Overview of basics of Control Banding
•  How Control Banding has been applied
   to Operations at th...
Control Banding
Control Banding - increased national and international
  attention
   –  as a practical approach to contro...
“Control Banding 101”, NIOSH
          http://www.cdc.gov/niosh/topics/ctrlbanding/

•  Control banding - a process in whi...
“Control Banding 101”, NIOSH cont.
•  The most developed CB model for control banding has been
   established by the Healt...
CB can be applied to categories of chemicals or
their mechanism of toxicity (Table 1 =Inhalation)
Application can be prosp...
Does control banding work?
             YES
•  The German authority (Bundesanstalt für
   Arbeitsschutz und Arbeitsmedizin...
Design and Application of Controls Center for
   Nanophase Materials Sciences (CNMS)

•  CNMS Laboratories, designed to pr...
CNMS method for CB in
         prospect
•  Research Safety Summary (RSS)
   process, flag priority chems.
•  At project pl...
A Conceptual Idea for Conducting Exposure Assessment as
  Part of the CNMS Work Control Process Using Control
       Bandi...
A Control Band (CB) designation reflects a belief about the level of
control for a particular process. Validation of the p...
The initial CB designation may be assigned on the basis of process
knowledge, exposure data from a similar exposure group/...
Once a control band is validated it
               Initial          represents the control status of the
            Contr...
Developing belief about a process/activity based on:



       Sampling data                Cutting and Cold Forming Cadmi...
Developing belief about a process/activity based on:



     Process            Cutting and Cold Forming Cadmium Sheet Met...
Selection of initial control band (process knowledge and prior
monitoring)


        Bayesian analysis of the
        samp...
EXAMPLE


                                  Decision Probability
                                                         ...
Process control band validation feeds back into data
bases ensuring initial designations reflect actual work
places and pr...
For future use from the book of control bands:


                                                                    Manua...
Two CB examples, from the
           CNMS
•  First example is a polymer processing
   system and determining if CB/Control...
Similar Exposure        Polymer Collection using solvent systems in fully
        Group or Task          enclosed process ...
Monitoring to validate control band designation and associated controls.




                           Table 1. Results o...
Monitoring to validate control band designation
                              combined with belief about process control i...
Carbon Laser Ablation Process
                    Ambient background outside
                    clean room (11,000 p/cc)
...
Industrial Hygiene Controls
         HEPA vacuum used to move all nano
         material from quartz tube into collection
...
Industrial Hygiene Controls

                           Harvesting nano materials by enclosing
                           ...
Hazard Assessment
                                  Nano material
                                  created is larger
    ...
Ensuring Exposure Control for a New Process

 nitial hazard assessment initiated in research safety summary –
  I
a docum...
Similar                        Laser ablation nano particle generation
                              Exposure
            ...
Summary for laser ablation

•  rocess is controlled using existing methods (clean room, HEPA
 P
vacuum, enclosure, local e...
Conclusions
•  Efficient and effective method for hazard
   analysis in the R&D environment
•  Provides a formal process f...
Upcoming SlideShare
Loading in...5
×

Banding Nano

354

Published on

Published in: Business, Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
354
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
12
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Banding Nano

  1. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 18. Process control band validation feeds back into data bases ensuring initial designations reflect actual work places and practices.
  19. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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
  1. A particular slide catching your eye?

    Clipping is a handy way to collect important slides you want to go back to later.

×