Section E: Provisions for Particularly Hazardous Materials
1. Chemicals of Chronic or High Acute Toxicity
Definitions:
- Carcinogen: Substances
that are suspected or known to cause cancer. Some have threshold
limits of exposure. (A list of carcinogenic chemicals can be found in Appendix G.)
- Mutagen: Chemical
or physical agent that causes genetic alterations
- Teratogen: Substances
that cause the production of physical defects in a developing fetus or
embryo.
- Substances with a High
Acute Toxicity: Any chemical
falling within any of the following OSHA defined categories:
- A chemical that has a LD50
of 50 mg/kg or less when administered orally to a test population.
- A chemical that has a LD50 of
200 mg/kg or less when administered by continuous contact for 24 hours to
a test population.
- A chemical that has a LC50 in air of 200 ppm
or less of a gas or vapor, or 2 mg/L or less of mist, fume, or dust when
administered by continuous inhalation for one hour to a test population.
General Guidelines
- As a general rule, all
chemicals of known or potential carcinogenic properties will not be used
unless no suitable alternative is available.
- Prepare a plan for the use
and disposal of these materials before beginning any laboratory work.
- Be prepared for accidents
and spills. Know the location of all safety equipment. Have the
appropriate clean up equipment on hand. The appropriate clean up supplies
can be determined by consulting the material safety data sheet.
- The proper personal
protective equipment including gloves, ensure gloves are impervious to the
chemical being used, and a long sleeved lab coat must be worn.
Storage Guidelines
- Chemicals of chronic or high
acute toxicity shall be stored in a cool dry location with warning signs
and adequate ventilation.
- Chemicals of chronic or high
acute toxicity can be stored in a laboratory if a designated area is set
up and properly labeled as such.
- Store all containers of
prepared solutions that contain a chemical of chronic or high acute
toxicity on a tray to contain spills.
- All containers must be
clearly labeled and must include the appropriate health hazards.
Handling Guidelines
- All work should be performed
in a fume hood. The area in which the research is being carried out must
be clearly marked with warning signs if left unattended, such as
"Warning: Highly Toxic Substance in Use".
- If a chemical of chronic or
high acute toxicity is transferred to a secondary container, the container
must be properly labeled with the name of the chemical (chemical formulas
and structural formulas are not acceptable), date, your supervisors name,
and the health hazard.
- Never leave a container of
chemical of chronic or high acute toxicity opened or unlabeled.
- Clean up small spills
thoroughly.
- If a spill occurs outside
the fume hood, evacuate the area and notify your instructor or the
chemical hygiene officer.
- When you are finished
working, clean all areas where the chemical was used.
- All empty containers that contained
a chemical of chronic or high acute toxicity, including the original
manufacturer bottle, must be washed with water twice with the washings
being treated as waste.
- Remove all protective
equipment before leaving the lab. Wash your hands and any other exposed
body surface thoroughly.
2. Compressed Gases
Definition:
A compressed gas is any material or mixture having in the container an
absolute pressure exceeding 40 psia at 21 °
C (70 ° F), or a pressure
exceeding 104 psia at 54 ° C
(130 ° F), or any flammable
liquid material having a vapor pressure exceeding 40 psia at 38 ° C (100 ° F).
General Guidelines
- Compressed
gas cylinders should be handled as high-energy sources and therefore as
potential explosives.
- All
cylinders, full and empty, must be restrained.
- Before
using a compressed gas, be familiar with the properties of the gas.
- Always
wear your safety glasses when handling compressed gases.
- Do
not extinguish a flame involving a highly combustible gas until the source
of gas has been shut off.
- If
you are using a compressed gas that is not listed below, you must consult
the chemical hygiene officer so that the proper procedures for that gas
can added to the chemical hygiene plan.
- Gas
cylinders can only be ordered from companies that will accept the return
of empties.
- Whenever
possible, lecture bottles must be ordered from companies that accept the
return of partially filled or empty cylinders.
- The
contents of any compressed gas cylinder must be clearly identified by the
manufacturer. Any cylinder that is not clearly identified will not be
accepted and will be returned to the manufacturer. Color-coding is not a
reliable means of identification.
- Contents
of the cylinder must be visibly labeled including hazard class, as
indicated below. The label facing
the wall is not acceptable.
- Paper
tags will be used on all cylinders to indicate the state of the tank as:
Full, In Use, or Empty.
- All
compressed gas cylinders must be clearly marked and identified with the
proper labels or tags as indicated in the table below:
|
Compressed Gas
|
Must be labeled as
|
|
Acetylene
|
Flammable Gas
|
|
Argon
|
Non-Flammable Gas
|
|
Helium
|
Non-Flammable Gas
|
|
Hydrogen
|
Flammable Gas
|
|
Nitrogen
|
Non-Flammable Gas
|
|
Nitrous Oxide
|
Non-Flammable Gas
|
|
Oxygen
|
Oxygen Containing Gas
|
Storage Guidelines
- When
a new cylinder is received:
o
It must be immediately inspected to insure it is
not leaking, that the proper cap is securely in place, and that it is properly
labeled.
o
The proper hazard identification tag must be
secularly fastened to the tank. Do not fasten any tags to the cap of the
cylinder. All tags must be securely attached to the cylinder.
o
A status tag indicating that the cylinder is
full must be secularly attached to the cylinder. The date the cylinder was
received should be added to the top of the status tag.
o
All extra gas cylinders will be located in the
chemical storage building. They must be secured at all times. Valves are to
remain closed and caps are securely in place when not in use.
o
Oxygen cylinders cannot be stored in the same
vicinity as flammable gases. Therefore,
DO NOT store flammable gases in the compressed gas storage room in chemical
storage building.
o
Empty cylinders must be identified as emptied and
returned to the chemical storage building and separated from full cylinders.
Handling Guidelines
- In
use cylinders must be secured at all times to prevent tipping, falling, or
rolling. They must be securely attached to walls, benches, or other fixed
surface with chains or straps.
- Regulators
are gas specific and not necessarily interchangeable. Always make sure you
are using the proper regulator.
- Check
for leaks with soapy water.
- Cylinder
valves should be opened slowly and only after the proper regulator has
been attached.
- Never
use any kind of lubricant on valve regulators.
- There
shall be no smoking or open flames in areas were flammable compressed
gases are being stored or used.
- Be
aware that rapid release of a compressed gas will cause an unsecured gas
hose to dangerously whip around.
- Do
not extinguish a flame involving a highly combustible gas until the source
of the gas has been shut off.
- Rapid
release of a compressed gas builds up a static charge that could ignite
the gas if it is flammable or combustible.
- Never
bleed cylinders completely. Leave a
slight pressure to keep out contaminants.
- Acetylene
cylinders:
o
Always store acetylene cylinders upright.
o
Do not use an acetylene cylinder that has been
stored or handled in a non-upright position until it has sat for in an upright
position for at least 30 minutes.
o
Ensure that the outlet line of an acetylene
cylinder is protected with a flash arrester.
o
Never exceed the pressure limit indicated by the
warning red band of an acetylene pressure gauge.
o
Ensure that the tubing being used for
transporting acetylene gas is appropriate. Some tubing materials such as copper
form explosive acetylides.
Transportation of Compressed Gas Cylinders
- Use
only the gas cylinder cart, properly designed for moving gas cylinders,
when moving a cylinder.
- Do
not drag, roll or slide cylinders.
- Secularly
strap the cylinder to the cart.
- The
valve should be closed and the cover cap secured in place before moving
the cylinder. Do not move a cylinder with a regulator.
- Handle
only one cylinder at a time.
- Do
not ride the elevator with a compressed gas cylinder.
- Students
are not allowed to transport compressed gas cylinders by themselves. They
must be properly trained and must be accompanied by a faculty/staff
employee.
Lecture Bottles
- Whenever
possible, lecture bottles must be ordered from companies that accept the
return of partially filled or empty cylinders.
- Regulators
are gas specific and are not necessarily interchangeable. Always make sure
you are using the proper regulator.
Name all associated equipment with the gas name to prevent
unintentional mixing.
- Lecture
bottles must be inspected twice a year for signs of leakage and/or
corrosion. If the bottle shows
signs of leakage and/or corrosion, the bottle must be returned to the
supplier or special arrangements must be made for disposal.
3. Corrosive Chemicals
Definition- The definition of corrosive chemicals is very
broad. In general terms a corrosive chemical can be defined as a chemical where
living tissue as well as equipment is destroyed on contact. Strong acids and
bases, dehydrating agents, and oxidizing agents are commonly considered
corrosive chemicals. A list of common corrosive chemicals is found in Appendix H.
General Guidelines
- The following is a list of
the major classes of corrosive chemicals.
|
Strong Acids
|
Concentrated acids can easily attack skin and eyes causing
severe and painful burns. Hydrofluoric acid is an extremely dangerous
material and all forms, including vapors and solutions, can cause severe,
slow-healing and painful burns.
|
|
Strong Bases
|
Alkali metal hydroxides are very destructive to the skin
and particularly to the eyes.
|
|
Dehydrating
Agents
|
Dehydrating agents have a strong affinity for water. When
they are added to water too rapidly, a violent reaction accompanied by
spattering can occur. These substances can cause sever burns on contact with the
skin or eyes.
|
|
Oxidizing
Agents
|
Powerful oxidizing agents are considered corrosive
chemicals. The halogens are strong oxidizing agents and because they are
gases they pose danger to sensitive tissues through inhalation.
|
Storage Guidelines
- Large quantities of
inorganic corrosives will be stored in acid room of the chemical storage
building in a clearly labeled area.
- Large quantities of organic
corrosives will be stored in a separate area of the organic storeroom and
clearly labeled as such.
- Smaller working quantities
of concentrated acids should be stored in corrosive cabinets.
- Storage areas must be kept
dry, well ventilated and cool, but not cold as acetic acid freezes at 60° F (16°
C)
- Isolate corrosives from all
other nearby chemicals.
- Whenever possible, store
corrosives in their original shipping containers.
- Acid spill control material
must be readily available.
- Store corrosives four feet
or less above the floor.
- Recognize that some acids,
such as perchloric and fuming nitric, must be treated as strong oxidizers
rather than acids.
- Separate corrosives that
will react with other corrosives.
- Perchloric acid cannot be
used in Sims. Perchloric acid
requires a special perchloric acid hood which is not available in Sims.
Handling Guidelines
- Eye protection, indirect or
nonvented splash goggles, must always be used when handling corrosive
materials.
- Chemical resistant rubber
gloves, a face shield and a heavy-duty rubber apron may also be
appropriate, such as when working with concentrated corrosives. Such
personal equipment is not necessary when working with dilute acids and
bases since washing with water is sufficient in decontaminating the skin.
- Never add water to acid.
When diluting a concentrated acid, always add acid slowly and
cautiously to water.
- Corrosive chemicals can
only be used in areas that are equipped with an eyewash station and safety
shower.
- In the event of skin or eye
contact with a corrosive chemical, remove all affected clothing and
immediately flush the area with cool water for 15 minutes. Seek medical
help.
- Procedures involving
concentrated corrosive chemicals or chemicals that may result in the
generation of corrosive fumes, gases, vapors, aerosols and/or dusts must
be conducted in a fume hood.
- Be prepared for
spills. For large spills of
corrosive chemicals, evacuation of the building maybe required.
- When strong corrosives are
used in student experiments, the students must be informed on the nature
of the corrosive and any precautions that must be followed.
- Perchloric acid is a
powerful oxidizing agent. Most fume hoods are not suitable for the using
perchloric acid. Sims is not
equipped with a perchloric acid hood.
- Because dry picric acid is a highly explosive. Therefore, picric acid should only be
purchased if no suitable alternative is available. Before purchasing
picric acid, permission form the chair must be obtained, and a thorough
investigation into the hazards of picric acid must be completed. A maintenance schedule to ensure that
picric acid does not dry out must be established.
- Dry picric acid is
explosive. Any old container of picric acid that dried up must be disposed
of only with expert assistance. Do not move the container.
- Hydrogen fluoride is
very toxic both as a gas and in solution. Do not use hydrogen fluoride
until you have thoroughly familiarized yourself with its properties and
safe handling procedures. Even contact with dilute solutions of
hydrofluoric acid can result in a serious burn.
4. Cryogenic Liquids
Definition- Liquefied gases that condense oxygen from the air create an
oxygen rich atmosphere and increase the potential for fire if flammable or
combustible materials and a source of ignition are present.
General Guidelines
- A number of hazards may be
present from the use of cryogenic liquids. All employees and students
should be properly trained in using such materials prior to use.
- Tissue damage, similar to a
thermal burn, will result with even very brief contact with a cryogenic
liquid including any surface cooled with the liquid.
- Always wear safety glasses
with side shields or goggles when handling. Wearing a face shield is also
recommended.
- Gloves should be impervious
and sufficiently large to be readily thrown off should a cryogen spill.
- Watches, rings, and other
jewelry should not be worn.
- All rooms were cryogenic
liquids are used, must have an oxygen sensor.
Storage and Handling Guidelines
- Containers and systems
containing cryogens should have pressure relief mechanisms.
- Containers and systems
should be capable of withstanding extreme cold without becoming brittle.
Do not transfer any cryogenic liquid into a nonapproved container. Transfer liquid nitrogen only into glass
Dewar flask approved for cryogenic liquids.
- Adequate ventilation is
required when using liquid nitrogen or helium. Oxygen can be condensed out
of the atmosphere creating a potential explosive situation. Also, oxygen
can be displaced from the atmosphere causing an oxygen deficiency
resulting in asphyxiation.
- Never ride on the elevator
when transporting a cryogenic liquid.
5. Flammable and Combustible Liquids
Definitions:
- Flammable liquids- any liquid having a flashpoint* below 38 °
C (100 ° F).
- Combustible liquids – any liquid having a flashpoint at or
above 38 ° C (100 ° F)
These liquids are further subdivided into
three groups:
|
|
Flashpoint
|
Boiling
Point
|
Examples
|
|
Flammables
|
|
|
|
|
Class IA
|
< 22.8 ° C (73 ° F)
|
< 37.8 ° C (100 ° F)
|
acetaldehyde, ethyl ether, cyclohexane
|
|
Class IB
|
< 22.8 ° C (73 ° F)
|
³ 37.8 ° C (100 ° F)
|
acetone, benzene, toluene, ethanol
|
|
Class IC
|
³ 22.8 ° C (73 ° F)
|
< 37.8 ° C (100 ° F)
|
Xylene, butanol
|
|
Combustibles
|
|
|
|
|
Class II
|
³ 37.8 ° C (100 ° F)
&
<
60 ° C (140 ° F)
|
|
acetic acid
|
|
Class IIIA
|
³ 60 ° C (140 ° F)
&
<
93.3 ° C (200 ° F)
|
|
cyclohexanol, formic acid, nitrobenzene
|
|
Class IIIB
|
³ 93.3 ° C (100 ° F)
|
|
formalin, picric acid
|
*The
flashpoint is defined as the minimum temperature at which a liquid gives off
vapor in sufficient concentration to form an ignitable mixture with air near
the surface of the liquid.
Storage Guidelines
- Bulk quantities of flammable
chemicals larger than four liters should be stored in the flammable
storage room of the chemical storage building.
- Flammable chemicals stored
in the laboratories should be stored in flammable storage cabinets and the
quantity should be kept to a minimum.
- Flammables should not be
stored in areas exposed to direct sun light.
- Appropriate fire
extinguishers and/or sprinkler systems and spill control materials will be
available in all areas where flammable chemicals are stored.
- All chemical storage rooms must
have a raised area in the doorway to contain spills.
- Any flammable chemical that
must be stored in the refrigerator or freezer must be stored in an
explosion proof refrigerator/freezer.
- Keep containers of flammable
substances tightly closed.
Handling Guidelines
- Large amounts of flammable
chemicals should be used only in vented hoods and away from sources of
ignition, which includes not only flames, but also electrical equipment,
static electricity and, for some material even hot surfaces.
- Smaller working amounts of
flammable chemicals should be used in vented hoods whenever possible and
away from sources of ignition.
- Heat flammable substances in
steam, water, oil, hot air baths or heating mantles only.
- To prevent differences in
electrical potential when transferring a flammable chemical from a large
container (5 gallons or larger) to a smaller container, the containers
must be grounded and bonded.
Nonmetallic containers must also be grounded and bonded.
6. Peroxide-Forming Chemicals
Definition- chemicals, which undergo autoxidation reactions (a reaction
with oxygen in the air) to form peroxides, which can explode with impact, heat,
friction, shock, sparks or light
- Peroxides and peroxide
forming chemicals are among the most hazardous chemicals handled in the
laboratory. Organic peroxides are particularly unstable and very sensitive
to impact. Anyone using such
chemicals should consider the following general information and should
thoroughly research information regarding any specific chemical to be used.
Storage Guidelines
- Date all chemicals that are
known peroxide formers upon receipt and upon opening.
- Store away from heat and
light sources
- Label such chemicals as
known peroxide formers.
- Limit stock of such
chemicals to a three-month supply.
- Keep the stocks of peroxide
forming chemicals to a minimum. Potential peroxide formers will not be
allowed to evaporate to dryness.
- Do not use metal storage
containers to store peroxide forming chemicals.
- Check for peroxide formation
every three months to a year depending on the chemical. See Appendix I.
- Do not open any container,
which has solid forming around its lid.
Handling Guidelines
- Before distilling any known
or suspected peroxide former, it must be checked for peroxides. Peroxide test stripes are located in the
refrigerator in Sims 304.
- When distilling peroxide
forming chemicals, the distillation apparatus should be assembled in a
hood and in such a way that it is possible to remove the heat source.
- Never return unused peroxide
forming chemicals to the original storage container.
- Do not use metal spatulas
when working with such chemicals.
- Follow the same handling
procedures outlined for flammable chemicals.
7. Water Reactive Chemicals
Definition- a material that when comes into contact with
water becomes spontaneously flammable or gives off a flammable or toxic gas and
presents a health hazard. Examples include alkali and alkaline earth metals
(sodium, magnesium, etc.), anhydrous metal halides (aluminum bromide, etc), anhydrous
metal oxides (calcium oxide, etc), nonmetal oxides (sulfur trioxide, etc),
nonmetal halide oxides (phosphoryl chloride, etc), and organometallics.
Storage
- Chemicals must be stored in
a dry area, such as a chemical storage cabinet.
- Should not be stored in the
same area as other combustible materials.
- Water reactive chemicals
should be clearly labeled as such.
Handling
- The utmost care must be
taken to avoid the contact of such chemicals with water.
- When using such chemicals,
one should thoroughly research information of their use.