Chapter 8: Chemical Management
A. Section 8.1.1 Introduction to Handling Chemical Waste
1.
Incident 8.1.1.1 The Stinking Building
2.
“Think Before You Sink”
a. Historically, Americans just want their waste gone, no matter the consequences
b. Chemical Industry used to dispose of waste in rivers/oceans or on the ground
c. Federal Regulations in the 1960’s and 1970’s prohibit this
d. Academic Lab: Don’t put anything in the trash or down the sink unless told to.
e. When can it go down the sink?
i. Introductory labs designed to produce innocuous, aqueous waste
ii. Green chemistry design may lead to sinkable waste
f. Most lab instructors address waste products in Pre-Lab discussion: follow direction
g. Reasons to dispose of chemicals properly
i. Environmental protection
ii. Safety
iii. Cost
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3. Protecting the Environment
a. The environment is a collection of chemicals
b. Our laboratory collection of chemicals may/may not be compatible
c. EPA (Environmental Protection Agency) makes the rules to govern waste disposal
i. Not a simple task: unlimited number of chemicals can exist
ii. Most chemicals have not been tested for environmental effects
d. Competing motives
i. It costs money to dispose of chemicals properly (prove it to be toxic)
ii. Desire not to harm the environment (prove it to be safe)
iii. EPA: chemicals are assumed harmful unless determined to be safe
e. Scale: 2ml might be ok to go down the sink, but 2 tons might not be
4. Disposing of Chemical Wastes Safely
a. Separate issue from environmental effects
b. Is it safe to dispose of the chemical in this way? Will we encounter risk?
c. Example: CN- down the sink, H+ down the sink (Makes HCN!!!)
d. CHEMICALS NEVER TO GO DOWN THE SINK
i. Azides (N3-)—explosive
ii. Perchlorates (ClO4-)—explosive
iii. Sulfides (S2-)—toxic gas formed with acids
iv. Cyanides (CN-)—toxic gas formed with acids
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e. Solids should not be poured down a sink: they will sit in the trap if not soluble
f. Solids shouldn’t be thrown in regular trash
i. Might react with something else in the trash
ii. Might come into contact with custodian
iii. Dispose of in proper waste container
5. Waste Disposal Costs Money
a. It may cost more to dispose of the waste than it did to buy the pure chemical
b. Private companies are often contracted by Universities to follow rules
c. Waste must be properly identified or the company doesn’t know what to do
d. Testing waste to determine what it is, is very expensive
e. What happens to the waste
i. Incinerated
ii. Recycled
iii. Processed in some way prior to disposal
iv. Buried in special containers in special landfills
6. General Guidelines (for the introductory lab student)
a. Follow instructions and Read Waste Container Labels carefully
b. Don’t pour anything down the sink unless instructed to do so
c. Broken glassware may be contaminated and needs to be disposed of as chemical
d. Know what the waste is, and don’t mix it with any other waste
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B. Section 8.2.1 Storing Flammables and Corrosive Chemicals
1.
Incident 8.2.1.1 Defective Chemical Storage Cabinet
2.
Minimizing Risks of Exposure
a. Corrosives and Flammables are the most common chemical hazards
b. Storage of these chemical classes requires proper equipment and practices
3.
Storing Corrosives
a. Both acids and bases are corrosive, yet they are incompatible with each other
b. Corrosive Storage Cabinets: no specific rules for how they are made
i. Metal is a bad idea, since acids react
ii. Painted metal often used, as the paint is organic and can handle acid
iii. Heavy molded Plastic (polyethylene) or Wood
Plastics can be molded seamless, containing spills
Some acids will react and degrade wood
Polyurethane coated wood is more resistant
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c. Separating Acids from Other Acids from Bases
i. Bases and Acids must be stored in separate corrosive cabinets
ii. Acetic Acid (oxidizable, organic acid) stored separately from inorganic acids
iii. Nitric Acid is a strong oxidizer never stored near organics
iv. Nitric and Sulfuric Acids may need secondary plastic containment: so reactive
v. NH3 + HCl -----> NH4Cl(s) precipitates on bottle is stored together
4. Storing Flammable Liquids
a. Keep a minimal supply in the lab: lab fire from ignition of flammables is serious
b. Double-Walled Steel with tight fitting joints used for Flammables Cabinets
c. Spills will be retained
d. Doors may be self-closing and self-latching
e. Must meet NFPA performance standards
f. Should not be near an exit or ignition source
g. Label: “Flammable—Keep Fire Away”
h. Some are vented (not required)
i. Removed fumes into hood system
ii. Vent from bottom, with make-up air
iii. Holes covered with “flame arrestors”
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5. Volume Limits and Flammables in the Lab
a. Fire code limits the volume of flammables based on fire rating of the lab
i. Wall thickness, sprinkler system etc…
ii. Better fire rating lab can have more flammables in it
b. NFPA rules followed by most states being phased out for GHS rules
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C. Section 8.3.1 Doing Your Own Laboratory Safety Inspection
1.
Incident 8.3.1.1 Unrecognized Hood Failure
2.
Maintaining a Safe Laboratory
a. Introductory Labs: this is the responsibility of the instructor and/or lab manager
b. Advanced Labs: Student should take more responsibility for own/others’ safety
c. Carrying out a Safety Inspection can identify hazards
i. Should be done informally once a month or so
ii. Goal: identify hazards you missed on a daily “working” basis
iii. Consider trading labs with someone else: fresh eyes
iv. Talk to research advisor about minimizing risks that are identified
d. It is often hardest to identify hazards that have become “familiar” to us
e. Focus on one or two areas and change that up each month
f. Housekeeping issues and Equipment Hazards should be examined each time
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D. Managing Chemicals in Your Laboratory
1.
Incident 8.3.2.1 Chemical Exposure and Fire from Old Stored Chemical
2.
Incident 8.3.2.2 Chemical Spill During Delivery to the Lab
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3. Responsibility for Managing Chemicals
a. Academic Labs: Who is Responsible?
i. Teaching Lab: department, instructor, lab manager, stockroom manager?
ii. Research Lab: professor, graduate student, post-doc?
iii. In General: If you ordered it, you are responsible for it.
b. Responsibility means:
i. Get it on the department (and maybe lab) inventory
ii. Know how and make sure of proper storage
iii. Dispose of properly
4. Factors for Consideration Prior to Ordering Chemicals
a. Do you have proper facilities to handle it?
b. Is there a less hazardous substitute?
c. Could you get away with less? (Smaller scale reaction?)
d. Does it already exist on-campus? Could you borrow or use up an old bottle?
i. Gets rid of hazardous chemicals not being used
ii. Doesn’t cost you anything
iii. An up-to-date department- or campus-wide
inventory is needed
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5. Minimizing Chemical Orders
a. Cradle-to-Grave Responsibility: are you sure you want that much?
b. ACS Green Chemistry booklet “Less is Better: Guide to Minimizing Waste in Labs”
c. “Just-in-Time Delivery”
i. Order supplies just before you need them, so you don’t have to store them
ii. Possible with chemicals: next day shipping often available
iii. Minimum quantities are usually pretty small (1 g)
iv. May cost more on a per gram basis, but may increase safety of the lab
v. Sometimes impractical: Grant money expires before need for chemical does
6. Receiving Chemicals
a. Inspect the container to make sure it is ok
b. Go over the MSDS (which may arrive with or separately from the chemical)
c. Date the container, but don’t obscure the label (where safety information is)
d. Label with the owner’s name
e. Special labels may be required for inventory scanning
f. Enter the chemical into the inventory
7. Movement of Chemicals
a. Let receiving department know if you are getting a particularly hazardous chemical
b. May want to pick-up and/or open package yourself, and in a hood
c. Shipping chemicals requires training and adherence to DOT rules
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E. Chemical Inventories and Storage
1.
Incident 8.3.3.1 The Exploding Bottle
2.
General Considerations in Chemical Storage
a. Logical searching order (alphabetical order) may not be safe
i. Incompatibles must be separated
ii. Flammables must be stored in special cabinets
iii. Some chemicals have to be refrigerated (or even stored in freezers)
b. Most chemicals are purchased and used in relatively small quantities
c. Solvents and Acids are generally found in 4L bottles
d. Stockrooms have primary responsibility for Departmental Chemicals
e. All Labs store some chemicals in the lab and must follow good practices
i. How long can you keep it?
ii. What conditions (fridge? darkness?) are best for storage
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f. Improper Chemical Storage results in many laboratory incidents
i. Storing Incompatibles together
ii. Not tracking peroxides
iii. Storing too much flammables
g. No Universal System of Chemical Storage Exists!
3. The Continuous Process of Maintaining a Chemical Inventory
a. Uses
i. Locating, sharing, and tracking chemicals
ii. Hazard identification and classification for storage
iii. Compliance with regulations and codes
iv. Cleaning up spills and information for emergency personnel
v. Planning and space management
b. Minimizing inventory saves in disposal cost later, and hazards now
c. What information is needed
i. Chemical name
ii. Molecular Formula
iii. CAS number
iv. Source and Size
v. Date received
vi. Location
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4. Compatibility Determines Proper Storage
a. Separate Chemicals into Incompatible Groups
i. Acids, Bases, Oxidizers, Pyrophorics
ii. Store separately and according to best practices for each group
b. Problems with Incompatible Storage
i. Some chemicals are in multiple groups
- Nitric Acid is an inorganic acid and an oxidizer
- Acetic Acid is an organic acid and combustible
ii. Vendors may not identify chemicals into these classes
- MSDS
- Bretherick’s Handbook of Reactive Chemical Hazards
- NIOSH Pocket Guide to Chemical Hazards
iii. Advanced Chemical Knowledge may be required to classify correctly
iv. Finding space and correct storage equipment may be difficult
c. Several systems for chemical storage exist: none is perfect
i. US Coast Guard “CHRIS”
ii. Texas A&M
iii. MIT
iv. National Research Council
v. Etc…
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5. Time-Sensitive Chemicals
a. Some chemicals degrade with time to more hazardous forms (ethers into peroxides)
b. These need to be dated, tracked, and discarded after a specified period
c. No one else is going to do it for you
d. Picric Acid: used for staining slides, making picrate salts, and in drug screening
i. Picric Acid = 2,4,6-trinitrophenol, a close relative of trinitrotolune (TNT)
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ii. Purchased as a “wetted” with > 30% water
iii. Becomes explosive if < 30% water
iv. Much like peroxides, if you find dried out picric acid, call bomb squad
Chemical Storage Locations, Cabinets, and Shelving
a. Don’t store chemicals in hoods
i. Hoods are safe places for storage, but they are intended for use in reactions
ii. Storing chemicals takes up space, moves reactions to benches
b. Flammables: require NFPA approved flammable cabinet
c. Follow NFPA limits for volumes of flammables allowed in labs
d. Stockrooms should have constant turnover of air, so not to accumulate fumes
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e.
f.
g.
h.
i.
j.
k.
Acids stored in plastic or wooden shelved cabinets
Reactive materials should be stored out of direct sunlight
Organic Peroxides stored in refrigerators (spark-proof, explosion-proof)
Shelves can’t be overloaded or too crowded (so that you knock stuff off)
Shelves should have a front lip to prevent spillage in earthquakes
Shelves should be attached to the wall, not free standing to prevent tipping
Plastic secondary containment trays are a good idea for spills
F. Section 8.3.4 Handling Hazardous Lab Waste
1.
Incident 8.3.4.1 Tollen’s Test Explosion
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2. Incident 8.3.4.2 Down the Drain
3. What Happens to Hazardous Waste from the Lab
a. In the advanced lab, or in a job, no one will prepare waste beakers for you
b. You have to decide how to collect and store waste until it is removed for disposal
c. Environmental, Health, and Safety offices usually collect and pay private companies
to dispose of chemical waste properly
d. EPA Guidelines for handling Hazardous Waste
i. Can only keep it on hand for so long
ii. Must identify the contents
iii. Transportation and Packaging are regulated
iv. Disposing of the waste is regulated
v. You need to obtain final proof of disposal from the company
4. Tollen’s Reagent
a.
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b. Silver and ammonium ion shouldn’t be stored together
c. Silver nitride can form, which is explosive: Ag3N
d. Acidify the solution with dilute acid prior to disposal to prevent explosions
5. Your Role in Hazardous Waste Disposal
a. Primary Responsibilities
i. Identify components and handle them properly
ii. Minimize hazardous waste
b. Hazardous Waste can’t be disposed of without identifying what it is
i. Very costly to have company analyze the waste
ii. Keep running records of waste as it is accumulated
Halogenated Solvent Log Sheet (CPP 210)
Date
Solvent
Volume
Initials
c. Must keep incompatibles in separate waste containers (HNO3 and CH3COOH)
6. Compliance with Regulated Hazardous Chemical Waste
a. RCRA (Resource Conservation and Recovery Act) requires significant paperwork
b. Rules depend on how much waste you generate
i. Exempts small quantity generators:
- < 100 kg/month hazardous waste
- < 1 kg/month of acutely toxic waste in a given month
ii. Small Quantity: 100-1000 kg/month, can’t have > 6000kg on hand, 180 days
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iii. Large Generators: > 1000kg/month, 90 day storage limit
c. Accumulated Waste is usually separated into comparable groups
i. Labpacks = Barrel or drum, filled with bottles of waste in vermiculite
ii. Transported by certified transporters to company for disposal
d. What makes waste Hazardous?
i. Flammability
ii. Corrosive
iii. Reactivity
iv. Toxicity
7. Minimizing Waste: Less is Better
a. Don’t order more than you need
b. Substitute non-hazardous for hazardous
c. Use small-scale experiments if possible
d. Share chemicals with colleagues
e. Recycle or Reuse if possible
f. Separate waste as much as you can to ease treatment and recovery
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G. Section 8.3.5 Chemical Security
1.
Incident 8.3.5.1 Radioactive Iodide Poisoning
2.
Academic Labs and Security
a. Academics are generally not concerned with security
b. Labs may be left unlocked for students to have access at night
c. Stockrooms are usually locked
d. Equipment and chemicals can easily be obtained from unsecure academic labs
3. What might be stolen
a. Poisons: Criminals in need of poisons often try to obtain it from academic labs
b. Drug Making chemicals/supplies: rare, but happens, lab balances often disappear
c. Explosives: strictly regulated, but can be stolen from unsecure labs
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4. Securing Hazardous Materials in the Lab
a. Goal: prevent injury by restricting access to hazardous materials
b. Physical Facilities
i. Challenge at a college, because buildings are mostly unlocked and open
ii. Lab doors need to be locked
iii. In England, student must have a swipe card to get into chemistry building
iv. Industry: fences, guards, key cards, etc…
c. Personnel
a. Background checks of employees are possible
b. Impossible to screen students
c. Most likely a perpetrator works at the lab, rather than being outsider
d. Report suspicious behavior or people in the building who usually aren’t
d. Materials
a. High Hazard materials should be kept in locked cabinets or fridges
b. Radioisotopes have been treated this way for decades
c. Explosives, poisons, drug precursors should be considered for this treatment
e. Information
a. Need to know basis; don’t publicize what you have or how much or where
b. Requirement for posting safety signs might tell what is in there
c. Inventory should only be available to those needing to know
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f. Shipping High Hazard Materials
i. Don’t leave things on a desk for someone to pick up: sign for chemicals
ii. Sharing with colleagues should involve a formal process
iii. Chain-of-custody needed for chemicals you are responsible for
g. Reporting Incidents or Lost/Stolen Materials: follow University policy/procedure
5. Identifying High Hazard Materials
a. Chemicals
i. GHS Hazard Class 1 for toxic chemicals: restrict access
ii. Dept of Homeland Security: 300 chemicals are tracked/regulated as potential
weapons of mass destruction
- Must have a permit to use or transfer
- May not apply if amount doesn’t reach threshold
b. Biological
i. CDC, USDA, USDOJ regulate the most dangerous pathogens
ii. Specials laws apply to storage, shipping, use of these
c. Radioactive
i. NRC (National Regulatory Commission) licenses ability to use
ii. Constant surveillance and security required for decades
iii. Can lose license of security is not maintained
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