Much of this information is found in Standard Methods; there is also a CRC Handbook of Lab Safety, and many other volumes; Hazardous Chemicals Desk Reference (Sax & Lewis) has some general info
Overview
safety in the lab is the responsibility of the institution, the lab manager, supervisors and the lab worker
hazards can be encountered in the lab or in the field
safety requires proper training, available safety info, available safety equipment, inspection, updating safety info...
big labs do well to have a safety committee
people from different areas can often see hazards that others might not
the suggestions of people in the lab, the committee, or whoever should be taken seriously
recordkeeping: a log should be kept of all training, inspections, accidents etc.
like all records, these should be in a simple enough format so that people use them
enough info should be recorded concerning accidents so that appropriate changes/actions can be made
people working in a lab should be under the supervision of someone with training and knowledge concerning any hazards that might be present
employees have a "Right-to-Know" that is spelled out in the OSHA Hazard Communication Standard
hazards and emergency procedures associated with chemicals are spelled out in the MSDSs, these are shipped along with chemicals and should be available for review
mishaps often are not accidents: proper planning and organization usually prevents problems
Safety Equipment
available equipment should include:
fire extinguishers
water type: wood, paper, rags; don’t use on electrical fires or burning liquids or metals
dry chemical: effective against most fires, particularly those that water is not good against
carbon dioxide: typically used against small liquid fuel fires or electronic components
CAUTION: CO2 and Halon types create an oxygen deficiency!
all extinguishers must be regularly inspected and charged
fire blankets
safety showers
can be used to wash off hazardous chemicals or extinguish a clothing fire
eye wash fountain
NOTE: contact lenses are usually not recommended for wearing in the lab; always wear eye protection around flames, corrosive or irritating chemicals, glass under pressure or vacuum...
flush eyes immediately and thoroughly (15 min) in case of chemical contact
in case of particles in the eye, be careful about high pressure streams of water, get expert help ASAP
hoods should be fitted with a shield; if radiation is used, appropriate shield should be available
materials should be stored and transported in appropriate containers (and compatibilities should be observed)
fume hood
chemical spill kit
special equipment may be needed when working with radioactive material or dangerous pathogens
glove-box
laminar flow hood
all equipment should be periodically inspected for condition and function
personal protective equipment (PPE)
clothing: should protect the skin of the lab worker, lab coat can protect clothing and be left in the lab, in cases of radioactive materials, high concentrations of toxins, etc., disposable clothing can be used to prevent the spread of the hazard outside the lab
gloves: protect against acid spills, heat, cold, pathogens
safety shoes and hard hats where needed
safety glasses: provide some protection against chemical splashes, chips, powders, ultraviolet etc.
if using UV or laser, side shields can be very important
lens should be appropriate for environment (laser etc)
when using acids or bases, a face shield protects the skin of the face as well as the eyes
respirators
for some vapors, etc, a full face or half face respirator with appropriate cartridge (ammonia, chlorine, HEPA, acid, organic vapor etc) provides good protection (roughly 10 fold)
powered air purifying respirators (PAPRs) don’t have the same leakage problems, but for organic vapors, you’ll use up cartridges quite quickly
for environments with depleted oxygen or serious toxic gases (boron trifluoride, chlorine, dimethylamine, ethylene oxide, fluorine, hydrogen bromide, etc, atmosphere-supplying respirators (supplied air or SCBAs) are the way to go
respirators are not a substitute for appropriate engineering controls, the use of respirators is complex (Sax and Lewis has a chapter that gives a good summary)
Laboratory Hazards
a larger lab will often have a document that spells out what hazards are present; sometimes workers are required to sign off that they have read it
a safety plan would describe emergency procedures and exit routes and would include MSDSs as an appendix
general good housekeeping measures might also be spelled out, these would include prohibitions on:
eating, drinking, or smoking in the lab, to avoid ingestion or ignition
floor clutter to permit escape or access to fire extinguishers or other safety equipment
improper storage conditions
Chemical
many substances are harmful if they come into contact with the outside of the body or mucus membranes or if taken into the body through the GI tract, lungs, or skin
avoid getting chemicals loose in the lab
two types of exposure limits:
OSHA regulations include legally-enforceable Permissible Exposure Limits (PELs) that may be a few years out of date
ACGIH periodically publishes Threshold Limit Values (TLVs); up to date but not legally enforceable
inorganic acids and bases
fumes are extremely irritating to eyes, lungs, etc.; take special care when heating (which we will do later in the semester)
strong solutions can quickly cause severe burns of skin or eyes
store acids and bases separately in well ventilated areas, away from organics
use rubber or plastic buckets when transporting acids and bases
work in fume hood
slowly add acid to water (that’s what you oughta)
if you get some on yourself: thoroughly flush with water, don’t rewear the clothes until they are thoroughly washed (note: leather can retain acids even after rinsing with water); if irritation persists seek medical attention
if you get some in your eye: immediately flush for fifteen minutes and seek medical attention
sodium hydroxide is extremely irritating to skin, eyes etc.
solutions as weak as 2.5 M can cause serious eye injury
sulfuric acid and sodium hydroxide and other strong acids and bases can readily boil water when added to quickly
metals and inorganic compounds
use caution when working with any lab chemicals
arsenic, nickel, mercury, lead and other metals are toxic; mercury is a liquid with significant vapor pressure at room temp.
azide is toxic and can form explosive metal azides when sitting in metal drain lines
cyanide solutions can form hydrogen cyanide gas when acidified
organic compounds
many solvents have TLVs
many organic solvents and reagents are carcinogens
chlorinated solvents cause liver and brain damage, may be carcinogenic, and can knock you out
alcohols are intoxicants and may pose a fire risk
hydrocarbons are irritants and may pose substantial fire risk, a few are carcinogens
ether is especially nasty to work with:
extremely flammable
when evaporated to dryness, it produces explosive peroxides (store in tightly closed light-proof bottles in explosion-safe fridge
it can knock you out
it causes eye and skin irritation, headaches, dizziness, nausea, unconsciousness, death, etc
organic reagents are typically solids which produce airborne vapors or particles that can be irritating or toxic
remember that lab samples may contain nasty contaminants
Biological
samples or cultures in the lab may contain pathogenic microorganisms
these can be a problem if accidentally ingested or somehow introduced under the skin (eg through a cut or needle stick)
sample handling can also sometimes create aerosols
don’t pipet by mouth
discard used pipets into a jar of bleach or other disinfectent
sterilize (eg by autoclaving) all used implements, containers, etc before reuse or disposal
wash hands frequently
don’t take food or beverages into micro area
keep out flies
Radiation
radiation in the lab may be due to electronically produced radiation or radioisotopes used in instrumentation (eg Ni 63 in electron capture detector), in calibration standards or in samples
labs which have substantial radiation or radioactivity should provide radiation safety training to workers
some intruments, such as ICPs, graphite-furnaces, UV-sterilizers, produce harmful UV; use caution and safety glasses/shields when working around these
other instruments produce xrays, high-energy electrons etc
Physical
electrical
wiring should conform to the National Electrical Code
proper grounding is important, with GFI outlets where appropriate
careful with outlets and other spark hazards around flammable chemicals
careful about pulling the cover off an instrument, some components can supply a lethal jolt even with the instrument unplugged
mechanical
be sure moving parts are properly shielded
watch for movement due to vibration etc
compressed gases
handle properly
secure tanks
beware of leaking equipment, tanks, hoses, etc.; particularly when using flammable gases
nitrogen, helium, argon, CO2, etc can dangerously lower oxygen levels in some environments
refer to OSHA regs governing compressed gases
Other considerations
in some work environments, personal monitors are necessary
chemical monitors include personal air samplers with filters, impingers, or absorbants which can be used to determine average hourly or shift exposure to various airborne substances in the breathing zone
radiological monitors include film badges to gauge personal exposure as well as swabs and survey meters to determine environmental radioactivity and radiation
when workers are exposed to particular chemical or microbiological hazards (eg, lead or typhus), preemployment medical exams with periodic follow up may be appropriate and/or required by law
waste disposal
separate waste containers are needed for trash, broken glass, chemicals, biohazard, and radioactive waste
chemical waste
solvents can often be recycled commercially or locally
acids and bases can sometimes be neutralized and diluted for safe disposal
many substances can be treated to render them nonhazardous
most toxic metals or organic compounds can be consigned to a disposal contractor
biological wastes
autoclave before disposal
animal carcasses etc should be properly contained and incinerated
radioactive wastes
these are generally handled separately before consignment to a disposal contractor
quantities must be carefully recorded
disposal consists of either dilution and dispersion or concentration and containment
Housekeeping in Room 207
distilled water
fill squeeze bottles or other containers and bring the water back to your work area
after class
please, unless I say otherwise no one leaves until everyone is cleaned up