Monitoring of Airborne Nanoparticles in Research Laboratories at the Center for High-Rate Nanomanufacturing (CHN)

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1 Monitoring of Airborne Nanoparticles in Research Laboratories at the Center for High-Rate Nanomanufacturing (CHN) Candace Sujung Tsai, doctoral candidate Dept. of Work Environment University of Massachusetts Lowell 1

2 Group of Authors Sujung (Candace) Tsai Doctoral Student Kwangseog Ahn Postdoctoral Research Earl Ada - Microscopy Michael J. Ellenbecker Doctoral Advisor University of Massachusetts -Lowell Jacqueline Isaacs Leader, Societal Impacts Team, NSEC Northeastern University 2

3 OUTLINE 1. Research Background 2. Materials and Method 3. Monitoring and Analysis 4. Conclusion and Discussion 3

4 Exposure and Effect Exposure route: inhalation, dermal contact, ingestion Health effects based on animal experiments: 1.Greater adverse inflammatory response 2.Carbon nanotube - does-dependent dependent lung inflammation - inflammation (acute response) and fibrosis (chronic response) 3.Can translocate to other organs (brain, kidney, CNS) through circulatory system [Oberdorster et al. 2006] 4

5 Research Centers NSF NSEC 5

6 Research Objectives 1. Investigate exposure of airborne nanoparticles 2. Particle sampling method & analysis 3. Engineering and administrative controls 4. Recommended work practices 6

7 OUTLINE 1. Research Background 2. Materials and Method 3. Monitoring and Analysis 4. Conclusion and Discussion

8 Materials and Processes Measured 5 particles: Nanoclay, nanoalumina,, carbon black, fullerenes and carbon nanotubes Measured 7 processes: Electrospinning,, compounding, synthesis of carbon nanotube,, shaking-reaction of fullerene, compounding of twin screw extruding, silica handling and carbon black handling 8

9 Particle Sizer TSI Fast Mobility Particle Spectrometer (FMPS) 5.6 to 560 nm, 32 channels, 1 second cycle time, 10L/min flow rate 9

10 Particle Sizer Mobility particle size is measured by electrical mobility Comparative diameter to a spherical particle Can not distinguish the shape of particle Can be same mobility diameter (Dp) 10

11 Particle Loss in Tubing 3 m Tygon tubing Total concentration: 8-10% Avg. of all channels: 15-19% 11

12 Methods Measured concentrations: Particle number, surface area, and total concentration Measured locations: Background, source, and researcher s s breathing zone. Particle sampling: filter, filmed grid Particle analysis: SEM, TEM, EDS 12

13 OUTLINE 1. Research Background 2. Materials and Method 3. Monitoring and Analysis 4. Conclusion and Discussion 13

14 PROCESS 1. Nanocomposite Compounding 2. Synthesis of CNTs 3. Shaking-Reaction of Fullerene 4. Handling Nanoparticles 14

15 Nanocomposite Compounding Machine: Twin Screw Extruder (TSE) Materials: Polymer (5lb) + Nanoalumina ( lb) 0.25lb) Temperature: > 200 degree C Ventilation used: Local hood (poorly designed) 15

16 Nanoalumina Particles nm Avg. size 45nm Percent of concentration [%] Diameter [Dp/nm] 200nm Size distribution: Measured in hood Measured in aerosol loop 16

17 Measuring Location of TSE 17

18 Concentration and Median Diameter Total concentration [#/cm 3 ] 2.0E E E E E E E E E E E E+04 Twin Screw Warmup Calibration PMMA 2%Al2O3 5%Al2O Time (minute) Median diameter [nm] f

19 Introduced Nanoparticles At source 200nm 19

20 SEM of Particles at Source 200nm Figure: Polycarbonate filter at source (x33,000) 20

21 STEM of Particles at Source 100nm 21

22 Administrative Control Total Concentration [particle/cm 3 ] 7.0E E E E E E E+04 Background concentration after cleaning 0.0E+00 April 13, 06' (I) April 20, 07' (I) Sept. 06, 06' Sept. 27, 06' Oct. 19, 06' Nov. 01, 06' (II) Feb., 07' (III) March, 07' (III) April, 07' (IV) Time Frame 22

23 PROCESS 1. Nanocomposite Compounding 2. Synthesis of CNTs 3. Shaking-Reaction of Fullerene 4. Handling Nanoparticles 23

24 Synthesis of CNTs Process: chemical vapor deposit (CVD) Temperature: > 900 degree C Production: micro gram/batch Ventilation used: fume hood 24

25 Particle Generation 25

26 SEM of Nanoparticles 100nm 26

27 PROCESS 1. Nanocomposite Compounding 2. Synthesis of CNTs 3. Shaking-Reaction of Fullerene 4. Handling Nanoparticles 27

28 Shaking-Reaction Machine: Shaking-reaction device Materials: Fullerene 100mg, Nanoalumina 100mg Ventilation used: Fume hood No thread or gasket Shaking direction Reaction chambers 28

29 Shaking C60 - Source 29

30 SEM of Shaking Particles 100µm 30

31 PROCESS 1. Nanocomposite Compounding 2. Synthesis of CNTs 3. Shaking-Reaction of Fullerene 4. Handling Nanoparticles 31

Two different hoods/labs Variables: face velocity (sash location)

32 Handling Nanoparticles Material: nanoalumina 100g, avg. size-45nm Method: transferring and pouring Ventilation used: fume hood Two different hoods/labs Variables: face velocity (sash location) worker s s height Measurement: Source- upstream, downstream, Breathing zone, Lab background 32

33 Result at Hood A- Breathing Zone Number concentration [ particle/cm 3 ] 1.4E E E E E E E E+00 Pouring 100g nanoalumina vf= 1.0 m/s 190 ft/min, low sash vf= 0.6 m/s 114 ft/min, middle sash vf= 0.4 m/s 79 ft/min, high sash BZ 4 min after release stop, middle sash Diameter, Dp[nm] 200nm Note: Background concentration was subtracted. 33

34 Background concentration at breathing zone Airflow structure Number concentration [ particle/cm 3 ] 1.4E E E E E E E E+00 BZ before expt 200nm Diameter, Dp[nm] Reference: Kim, AM. IND. HYG. ASSOC. J. 52(7): (1991) 34

35 OUTLINE 1. Research Background 2. Materials and Method 3. Monitoring and Analysis 4. Conclusion and Discussion 35

36 Conclusion Elevated nanoparticle number concentration compared to background concentration was found for most processes Elimination of particle release at source is the primary solution Working safely requires both engineering control system and good work practices 36

37 Discussion and Further Work What is the significance of exposures such as these for human health? How can we characterize nanoparticle aerosols that are always complex mixtures of multiple origins? Nanoparticles sampling and analytical methods need to be improved. Practical controls need to be applied to reduce nanoparticle release 37

38 Acknowledgement Authors would like to acknowledge the financial support from the Nanoscale Science and Engineering Centers Program of the National Science Foundation (Award no. NSF ) THANK YOU! 38

11/7/2011. How are we exposed? How serious the exposure can be? Working with nanomaterials!? Dr. Candace SJ Tsai. November 9, 2011 TURI CE Workshop

11/7/2011. How are we exposed? How serious the exposure can be? Working with nanomaterials!? Dr. Candace SJ Tsai. November 9, 2011 TURI CE Workshop Dr. Candace SJ Tsai November 9, 2011 TURI CE Workshop How are we exposed? How serious the exposure can be? Working with nanomaterials!? How do we be exposed? Airborne or Liquid? 2 3 1 TSI Aerodynamic Particle