basic lab practices
TRANSCRIPT
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Overview
Lab Safety SOPs
Lab Techniques
Continuous Improvement
Resources and References
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Lab Safety
Review MSDS
Physical and Chemical Hazards Control Measures
Reactivity
First Aid Measures
Disposal
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Lab Safety6
EPA Chemical Compatibility Table
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Lab Safety
Housekeeping #1 safety problem within university labs12
Benefits of clean and orderly lab and manufacturing
environments
Decrease the likelihood of product/sample contamination
Minimize chances of long term health effects by minimizingpersonnel exposure
Decreases the probability of safety mishaps Contamination of energetic materials can result in increased sensitivity or ignition of the EM.
Accident investigations in explosives facilities frequently identify dust buildups as the initiation
source propagation path.1
Increases efficiency Unless safety has been demonstrated for the EM at hand,
cleaning agents containing basic alkali or alkaline earth metal
salts should not be used where nitrated organic explosives
may be present. More sensitive explosive compounds may
form1.
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Lab Safety
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Lab Safety
Spills Minimize the likelihood4
Maintain a neat and organized work area
Keep containers sealed when not in use
Use plastic or plastic coated containers
Secondary containment for storage and transport
Response Alert others in and around the work area
If the material is volatile, turn on nearby ventilation.
If there is possibility of an acute respiratory hazard, evacuate. You should already be familiar with the MSDSs for the chemicals you are working
with. If not, investigate the hazards before cleaning up or ask for help.
- Ensure that incompatible materials are not used to clean or contain the spill
Commercial spill kits are available, some of which are packaged in a container thatcan be used to lab pack the spill cleanup waste. They generally include absorbentmaterials to prevent the spread of and absorb the spill, as well as bags
Energetic material spills
- Notify supervisor- Take precautions to avoid initiation while cleaning avoid friction, heat, ESD,
impact and incompatible materials
Mercury spills
- Clean-up kits for mercury spills
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Lab Safety
Chemical Management All materials should be labeled
ID label must contain the Name, PN, Rev., LN, quantity and unit
Labels on items containing explosives must state the NEWt
NFPA label for hazardous materials/chemicals
Other useful information Concentration of prepared solutions
Date opened for materials that do not have an indefinite shelf life
Special storage requirements if any
Expiration Date
- Could be N/A for some items, such as silicon dioxide
- Always follow manufacturers label expiration date
Materials and supplies should have a defined and identifiedlocation, and should be kept there when not in use Organization must ensure chemicals that are incompatible are not
stored together
Inventory should be tracked so that waste quantities, materialage, and supply are known
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Lab Safety
Hazard Controls
Hazard Types Chemical Respiratory
Skin
Physical
Noise Explosion
Fire
Mechanical
Electrical
Ways to Control Hazard Exposure Eliminating hazard Engineering controls
PPE
Scale
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Lab Safety Design considerations for facilities10
Lab air No recirculation
Negative pressure relative to surrounding areas
Locate hoods away from doors, air vents, operable windows and traffic areas
- Incompatible materials should use separate extraction systems
- Exhaust stack height should be sufficient to prevent exhaust recirculation back into building - 10 ft works for most
applications
Fire safety More than one unobstructed egress
Flammables stored in appropriate cabinet
Desirable material properties for work surfaces/tools Non-sparking
Non-absorbent
Easily cleaned
Conductive
Chemically resistant
Safety showers and eyewashes 29CFR1910.151(c) states Where the eyes or body of any person may be exposed to injurious corrosive
materials, suitable facilities for quick drenching or flushing of the eyes and body shall be provided within the
work area for immediate emergency use.2
ANSI Z358.1 gives numerous requirements, including that the units should be activated weekly to ensure
correct operation and that they be located at a distance that takes no more than 10 seconds to reach.3
Portable units are good supplements but are not acceptable in lieu of stationary units 10
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Lab Safety
Intrinsically Safe Electrical Circuits
Class I (multiple groups)- for vapors existing between the lower andupper explosive limits
Class II (multiple groups)- for airborne dusts above the lower
explosive limit
Class III - for fibers usually associated with the textile industry
Class II G is often the class and group satisfying the conditions ofworking with explosives
Operational Shields Designed to protect workers from MCI detonation pressure, heat
and fragmentation whenever there is potential for an event.
Tested by simulating the MCI, taking into account workspacetooling and location
Post MCI design criteria for each shield
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Lab Safety
AE Heat Conditioning Device Requirements for
Laboratories1
Must have dual independent heat controllers
Must contain a mechanism for relieving overpressure
Must be vented
If heating elements are used, the design must be such that there is no
possibility of the AE coming into contact with the elements Fan blades must be non-sparking and the fan motor external to the oven
The inside of the oven shall be constructed so that it is easily cleaned
All metal parts not carrying electrical current shall be interconnected and
electrically grounded
Should be installed to give personnel protection from possible energetic
events.
- Quantity, location, and shielding
Separate ovens containing AE by the appropriate QD or use protective
measures to prevent propagation from one oven to the next. Do not place
AE in the same room as the oven unless it has been determined that an
event within the oven will not involve the materials outside of the oven.
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Standard Operating Procedures1
Purpose
Provide process consistency
Processing of EM should be performed remotely when possible Components
Safety Precautions1
MSDS
PPE
Emergency procedures Removal of unneeded explosives from the work area
References to other applicable documents1
Equipment, tools and supplies permitted for use1
Instructions for spill cleanup1
Instructions for scrap AE disposal1
Sample Preparation
Quality Control
Defined Limits and tolerances
Indicators for identifying abnormal conditions1
Troubleshooting
Cleaning1
Record Keeping
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Lab Techniques
Cleaning Solns for Volumetric Glassware e.g. pipettes, burets, vol flasks,
beakers, grad cylinders4
Solution Procedure
Warm 2% detergent solution Fill and use a brush if needed. Rinse with distilled/DI water
Hot dilute alkaline EDTA solution ~ 0.004M with pH =12. Soak for < 15min to avoid etching.
Rinse with weak acid followed by distilled/di water
Chromic acid cleaning solution Soak overnight at room temp or heat to 60C. Reuse until green.
Thoroughly rinse with water and then DI water to remove
chromium ions, which can interfere in EDTA titrations or
spectroscopic work
3-6M HCl or HNO35 Glass adsorbs trace chemicals, especially cations. Soak new
glassware or glassware used for critical work for >1hr. Rinse
with DI water, and then soak in DI water.
Solvent For many organics, a simple solvent rinse followed by the
detergent solution method works well
Cleaning Glassware
Many different approaches, depending on the use of the glassware and the contaminants to be removed
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Pipette Volume Ranges, mL
0
10
20
30
40
50
60
70
80
90
100
Microliter Syringe(Accuracy 1%)
Micropipette (Accuracy0.3-4.5%)
MIN
1 L
MAX
500L
MAX
1 mL
0
10
20
30
40
50
60
70
80
90
100
Vol Transfer Pipette(Accuracy 0.08-1.2%)
Bottletop Dispensers(Accuracy 0.5-1.0%)
MAX
100 mL
MAX
100 mL
MIN
500 L MIN
50 L
MIN
1 L
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Lab Techniques
Volumetric Transfer Pipettes5
Rinse the pipette with working solution before use
Use a rubber bulb to pull the liquid beyond the calibration mark
Replace the bulb with your index finger while gently holding the pipette
tip against the bottom of the vessel
Wipe the excess liquid from the side of the pipette
Touch the tip of the pipette to the wall of a beaker and drain the liquid
until the meniscus bottom reaches the center of the calibration mark
Drain the contents into the receiving vessel while holding the pipette tip
against the vessel wall
When the liquid stops draining hold the pipette against the wall for a few
more seconds before removing the pipette from the vessel
Do not blow out the residual liquid from the pipette
Rinse or soak the pipette after use. Removing deposits from the pipette
after the liquid has been allowed to dry can be difficult.
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Lab Technique
Micropipettes5
Set the desired volume if the pipette is adjustable
Wet the pipette tip for more reproducible volumes
Depress the plunger to the first stop, hold the pipette vertically and
place it into the liquid 3-5mm deep. The depth and angle of the tip will
affect the actual volume withdrawn.
Slowly release the plunger
Leave the tip in the liquid for a few seconds
Withdraw the tip without touching the sides of the vessel
Touch the tip to the receiver wall and press the plunger to the first stop
Wait a few seconds and then further depress the plunger to deliver theremaining liquid into the receiver
As micropipettes wear, the accuracy and precision can decrease by an
order of magnitude
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Lab Techniques
Electromagnetic Load Cell
Advantages -High accuracy -Simple structure
Disadvantages -Complex structure -Limited accuracy
Applications -Ultra-precision balances
such as analytical balances
-Small, cheap balances that
require only moderate
accuracy
-Large balances
Electronic Balances7
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Lab Techniques
Electromagnetic Type5
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Lab Techniques
Load Cell Type7
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Lab Techniques
Types and sources of error5,8,9
Air drafts T between sample and room/balance
Change of pressure due to swinging doors, ventilation, movement
Balance levelness
Object proximity to pan center
Moisture
T between the time of calibration and time of use Ex: A T=5C can cause 1mg error in measuring a 100g mass
Buoyancy Objects less dense than the standard mass appear lighter than the actual mass
Ex: 100.00 g of H2O weighed at 1bar and 25C has a true mass of 100.10g
Location (gravity) Adjust balance sensitivity
Static electricity Decrease by using ionizer or increasing humidity
Magnetism
Vibration
Using calibration weights that have been damaged or handled with bare hands
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Lab Techniques Errors in instrument response:
Balance sensitivity can be adjusted by the user - internal or external calibration Linearity error cannot be corrected by the user and should be defined by manufacturer
Weighing by difference is best practice.
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Lab Techniques
Calibration of Analytical Instrumentation
Calibration Standards High purity
Known concentration given by vendor or determined with a primary
standard Primary standards are >99.9% purity and should be stable in storage and under moderate heat so that it can
be dried
Calibration curves5
Determine the response of an analytical method to known quantities
of analyte
General Procedure for Curve Construction Prepare known samples of analyte whose concentrations bracket the expected sample concentrations. Use
at least six calibration concentrations and include a blank.
Measure the responses of the analytical procedure to the standards and record the data. Obtaining triplicatedata points for each concentration allows for more reliable rejection of outliers and a measure of method
precision.
Subtract the average blank response from each individual response, resulting in a corrected response.
Graph the corrected responses versus the known concentrations of analyte by fitting the data to a linear or
quadratic curve using a method of least squares.
When an unknown is analyzed, run a blank with the unknown and subtract its response from the unknown
response before using the calibration curve to determine the analyte concentration.
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Lab Techniques
Analyte concentration at Detection Limit for a linear fit5
3s/m s determined from response range within 5 DL
Response level that gives 99% chance that the analyte is actually
detected
Lower Limit of Quantitation The point at which the quantitative capability is
considered acceptable5:
One way is 10s/m
Another way is that replicate measurements will be within 20%
in accuracy and the CV < 20%
- CV = s/xbar * 100
Limit of Linearity
Sensitivity11 = m/s
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Lab Techniques
5DL
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Other Calibration Methods5
Standard Addition - used to account for matrix effects
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Other Calibration Methods5
Internal Standard Good for analyses where the sample quantity analyzed or the
instrument response varies with time.
Add a known amount of a substance that is not present in
the unknown into standards, samples, and blanks
Construct a calibration curve by plotting analyte signal /
internal standard signal vs. concentration of analyte.
Minimizes the impact of random errors on the determination
results, e.g. instrument fluctuations in flow rate
May reduce systematic errors, such as sample prep losses,
depending on the chemical nature of the internal standard
relative to the analyte
AX/[X] = F (AS/[S])
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Continuous improvement
First, understand the process and the history
Incremental and ongoing
Identify and improve inefficiencies
Developing skill sets Identify and correct safety concerns
Correcting/updating procedures
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Continuous improvement
Risk Assessment
Aids in determining if action should be taken to mitigate agiven risk
Risk = Consequence Severity X Probability
Insignificant Catastrophic
NearCertainty
ExtremelyImprobable
C ti i t
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Continuous improvement Process Mapping defines a process, how steps are related, communicates the problem to
others, and allows recognition of ways to eliminate waste
yes
no
yes
no
yes
no
yes
yes
no
no
yes
yes
no
no
yes no
Eliminate
yes
no
End Goal
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If the process so inefficient that it is difficult to determine where
to make improvements, start from scratch and draw up the idealstate.
Determine if the ideal state is obtainable or the state that is
closest to the ideal state and feasible.
Continuous improvement
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Continuous Improvement
Fishbone/Cause and Effect Diagram
Useful for identifying possible causes for a given defect or event
Focuses on determining the root causes before taking corrective action, increasing
the chances for the proper solutions to the problem
Defect
Machines Materials Measurements
Mother NatureManMethods
Poor PM
Antiquated
Humidity
Unknown Quality
No defined shelf life
No QC testing
Poor reproducibility
Inadequate training
No environmental control
Call for wrong materials
Spec outdated
Too open to interpretation
Experience
Absent
Training
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Several representatives closely connected to the
process should participate - perspectives
All ideas should be documented
What controls are there on the factors?
Has this problem occurred before?
Which factors interact with other factors?
Should improvement effort be spent on one factor or
distributed among several factors?
Continuous Improvement
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Lab Safety
Recurring Internal Audit Use a standard template Inspect
Lab signage
Safety equipment, e.g. hoods and safety showers
That appropriate PPE is in use
Housekeeping and organization Chemical safety and proper storage
Electrical safety
Basic fire safety
Lab waste disposal
Be thorough - ask questions Discuss discrepancies with manager
Generate report
Follow up
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Understanding and protecting against hazards Basic understanding of balances, pipettes,
calibration, and calculations
Importance of organization and cleanliness in
efficiency and quality Appreciation for the importance of adhering to
concise SOPs
Cumulative effect of continuous improvement
Important Concepts
OverallImprovement
Time
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Resource Links Safety
Emergency Response Guidebook 2012
Glove Selection Guidance Shower and Eyewash Requirements
OSHA PPE Informational Booklet
Free Chemical Reactivity Software
OSHA Lockout/Tagout
Spill Clean-Up
Non-sparking Tools Static Generated by Flowing Liquids
Metal Activity Series to Help Predict Potentially Hazardous Rxns
AE Requirements DoD Contractors Safety Manual for Ammunition and Explosives
UN Explosive Hazard Classification System and Codes
ATF Explosives Storage Requirements OSHA Explosives and Blasting Agents
Lab Technique/Procedures Organic Lab Technique
Organic Lab Technique II
http://phmsa.dot.gov/staticfiles/PHMSA/DownloadableFiles/Files/Hazmat/ERG2012.pdfhttp://phmsa.dot.gov/staticfiles/PHMSA/DownloadableFiles/Files/Hazmat/ERG2012.pdfhttp://www3.imperial.ac.uk/OCCHEALTH/guidanceandadvice/gloveinformationandguidance/gloveselectionguidancehttp://www3.imperial.ac.uk/OCCHEALTH/guidanceandadvice/gloveinformationandguidance/gloveselectionguidancehttp://www.grainger.com/Grainger/static/emergency-shower-eye-wash-station-requirements-120.htmlhttp://www.grainger.com/Grainger/static/emergency-shower-eye-wash-station-requirements-120.htmlhttp://www.osha.gov/Publications/osha3151.pdfhttp://www.osha.gov/Publications/osha3151.pdfhttp://response.restoration.noaa.gov/crwhttp://response.restoration.noaa.gov/crwhttp://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9804http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9804http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9804http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9804http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9804http://www.udel.edu/ehs/chemspillkit/chemspillguide.htmlhttp://www.udel.edu/ehs/chemspillkit/chemspillguide.htmlhttp://www-group.slac.stanford.edu/esh/eshmanual/references/toolsReqFlammable.pdfhttp://www-group.slac.stanford.edu/esh/eshmanual/references/toolsReqFlammable.pdfhttp://www-group.slac.stanford.edu/esh/eshmanual/references/toolsReqFlammable.pdfhttp://www-group.slac.stanford.edu/esh/eshmanual/references/toolsReqFlammable.pdfhttp://www.shimadzu.com/an/hplc/support/lib/lctalk/14/14lab.htmlhttp://www.shimadzu.com/an/hplc/support/lib/lctalk/14/14lab.htmlhttp://www.saskschools.ca/curr_content/chem30_05/6_redox/redox2_5.htmhttp://www.saskschools.ca/curr_content/chem30_05/6_redox/redox2_5.htmhttp://www.dtic.mil/whs/directives/corres/pdf/414526mp.pdfhttp://www.dtic.mil/whs/directives/corres/pdf/414526mp.pdfhttp://www.un.org/disarmament/convarms/Ammunition/IATG/docs/IATG01.50-UN_Explosive_Classification_System_and_Codes(V.1).pdfhttp://www.un.org/disarmament/convarms/Ammunition/IATG/docs/IATG01.50-UN_Explosive_Classification_System_and_Codes(V.1).pdfhttp://www.atf.gov/explosives/how-to/explosive-storage-requirements.htmlhttp://www.atf.gov/explosives/how-to/explosive-storage-requirements.htmlhttp://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9755http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9755http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9755http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9755http://chem.chem.rochester.edu/~nvd/http://chem.chem.rochester.edu/~nvd/http://orgchem.colorado.edu/Technique/Procedures/Procedures.htmlhttp://orgchem.colorado.edu/Technique/Procedures/Procedures.htmlhttp://orgchem.colorado.edu/Technique/Procedures/Procedures.htmlhttp://chem.chem.rochester.edu/~nvd/http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9755http://www.atf.gov/explosives/how-to/explosive-storage-requirements.htmlhttp://www.un.org/disarmament/convarms/Ammunition/IATG/docs/IATG01.50-UN_Explosive_Classification_System_and_Codes(V.1).pdfhttp://www.dtic.mil/whs/directives/corres/pdf/414526mp.pdfhttp://www.saskschools.ca/curr_content/chem30_05/6_redox/redox2_5.htmhttp://www.shimadzu.com/an/hplc/support/lib/lctalk/14/14lab.htmlhttp://www-group.slac.stanford.edu/esh/eshmanual/references/toolsReqFlammable.pdfhttp://www.udel.edu/ehs/chemspillkit/chemspillguide.htmlhttp://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9804http://response.restoration.noaa.gov/crwhttp://www.osha.gov/Publications/osha3151.pdfhttp://www.grainger.com/Grainger/static/emergency-shower-eye-wash-station-requirements-120.htmlhttp://www3.imperial.ac.uk/OCCHEALTH/guidanceandadvice/gloveinformationandguidance/gloveselectionguidancehttp://phmsa.dot.gov/staticfiles/PHMSA/DownloadableFiles/Files/Hazmat/ERG2012.pdf -
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References 1. DOD Contractors Safety Manual for Ammunition and Explosives DoD 4145.26-
M. Aug 16, 2012. Web.
2. OSHA. 29 CFR 1910.151(c). Aug 16, 2012. Web.
3. Grainger. Emergency Shower and Eyewash Station Requirements. Aug 16, 2012.Web.
4. Aikens, David A. Principles and Techniques for an Integrated ChemistryLaboratory. Waveland. 1981. Print.
5. Harris, Daniel C. Quantitative Chemical Analysis. 8thed. W.H. Freeman. 2010.
Print. 6. University of Arizona. Risk Management Services.
http://risk.arizona.edu/images/chemcompchart_image.jpg. Aug 16, 2012. Web.
7. Shimadzu. Electromagnetic Type and Load Cell Type. 21 Aug, 2012. Web.
8. Shimadzu. Learning About Electronic Balances. 21 Aug, 2012. Web.
9. Radwag. Good Weighing Practice in Pharmaceutical Industry. 22 Aug, 2012. Web.
10. Scott, Ralph A., Jr. and Laurence J. Doemeny. Design Considerations for ToxicChemical and Explosives Facilities. American Chemical Society. 1987. Print.
11. Skoog, Douglas A., Holler and Nieman. Principles of Instrumental Analysis.Brooks/Cole. 1998. Print.
12. Chemical and Engineering News. Dow Chemical Teams Up with Universities onLaboratory Safety. http://cen.acs.org/articles/90/i44/Dow-Chemical-Teams-Universities-Laboratory.html. 19 Nov 2012. Web.