Prudent Practices in the Laboratory Handling and Disposal of Chemicals (1995) / Chapter Skim
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Working with Chemicals
Working with Chemicals
Pages 79-106
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From page 79... ...
. ~ ~ ~ o.~.~u - posy for una:renctea Experiments and Working Alone 5.C.ll Responding to Accidents and Emergencies 5.C.ll.1 General Preparation for Emergencies 5.C.11.2 Handling the Accidental Release of Hazardous Substances 5.C.11.3 Notification of Personnel in the Area 5.C.11.4 Treatment of Injured and Contaminated Personnel 5.C.11.5 Spill Containment 5.C.11.6 Spill Cleanup 5.C.11.7 Handling Leaking Gas Cylinders 5.C.11.8 Handling Spills of Elemental Mercury 5.C.ll.9 Responding to Fires 5.D WORKING WITH SUBSTANCES OF HIGH TOXICITY 5.D.1 Planning 5.D.2 Experiment Protocols Involving Highly Toxic Chemicals 5.D.3 Designated Areas 5.D.4 Access Control 5.D.5 Special Precautions for Minimizing Exnc~ur~ in Hi~hlv Tovir Chemicals 5.D.6 Preventing Accidents and Spills with Substances of High Toxicity 5.D.7 Storage and Waste Disposal 5.D.8 Multihazardous Materials - -on—- -r ~ _~ 79 81 81 82 82 82 82 82 83 83 83 83 84 84 84 84 85 85 86 86 86 86 87 87 87 88 88 88 89 89 90 90 90 91 91 91 92 93 93
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From page 80... ...
80 PRUDENT PRACTICES IN THE LABORATORY: HANDLING AND DISPOSAL OF CHEMICALS 5.E WORKING WITH BIOHAZARDOUS AND RADIOACTIVE MATERIALS 5.E.1 Biohazardous Materials 5.E.2 Radioactive Materials 5.F WORKING WITH FLAMMABLE CHEMICALS 5.F.1 Flammable Materials 5.F.2 Flammable Liquids 5.F.3 Flammable Gases 5.F.4 Catalyst Ignition of Flammable Materials 5.G WORKING WITH HIGHLY REACTIVE OR EXPLOSIVE CHEMICALS 5.G.1 Overview 5.G.2 Reactive or Explosive Compounds 5.G.2.1 Personal Protective Apparel 5.G.2.2 Protective Devices 5.G.2.3 Evaluating Potentially Reactive Materials 5.G.2.4 Determining Reaction Quantities 5.G.2.5 Conducting Reaction Operations 5.G.3 Organic Peroxides 5.G.3.1 Peroxide Detection Tests 5.G.3.2 Disposal of Peroxides 5.G.4 Explosive Gases and Liquefied Gases 5.G.5 Hydrogenation Reactions 5.G.6 Reactive or Explosive Materials Requiring Special Attention 5.G.7 Chemical Hazards of Incompatible Chemicals 5.H WORKING WITH COMPRESSED GASES 5.H.1 Chemical Hazards of Compressed Gases 5.H.2 Specific Chemical Hazards of Select Gases 93 93 94 95 95 96 96 96 96 96 98 98 98 99 99 99 99 100 100 101 101 102 104 104 104 104
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From page 81... ...
Also, laboratory work frequently generates new substances of unknown properties and unknown toxicity. Consequently, the only prudent course is for laboratory personnel to conduct their work under conditions that minimize the risks due to both known and unknown hazardous substances.
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From page 82... ...
If an individual must wear contact lenses for medical reasons, then safety glasses with side shields or tight-fitting safety goggles must be worn over the contact lenses. 5.C.2.2 Avoiding Ingestion of Hazardous Chemicals Eating, drinking, smoking, gum chewing, applying cosmetics, and taking medicine in laboratories where hazardous chemicals are used should be strictly prohibited.
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From page 83... ...
5.C.2.3 Avoiding Inhalation of Hazardous Chemicals Toxic chemicals or compounds of unknown toxicity should never be smelled. Procedures involving volatile toxic substances and operations involving solid or liquid toxic substances that may result in the generation of aerosols should be conducted in a laboratory hood.
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From page 84... ...
Apparel giving additional protection (e.g., nonpermeable laboratory aprons) is required for work with certain hazardous substances.
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From page 85... ...
Because flammable materials are employed in so many common laboratory operations, basic prudent laboratory practice should always assume the presence of fire hazard unless a review of the materials and operations in the laboratory verifies the absence of significant hazard. For example, simple operations with aqueous solutions in a laboratory where no flammable organic liquids are present involve no appreciable fire hazard.
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From page 86... ...
Under unusually hazardous conditions, special rules may be necessary. Laboratory operations involving hazardous substances are sometimes carried out continuously or overnight with no one present.
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From page 87... ...
Laboratory workers should be aware of their level of expertise with respect to use of fire extinguishers and emergency equipment, dealing with chemical spills, and dealing with injuries. They should not take actions outside the limits of their expertise but instead should rely on trained personnel.
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From page 88... ...
5.C. 1 ~ .5 Spill Containment Every laboratory in which hazardous substances are used should have spill control kits tailored to deal with the potential risk associated with the materials being used in the laboratory.
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From page 89... ...
Upon their arrival, tell the fire department and emergency response team what hazardous substances are in the laboratory. · If a person's clothing catches fire, have him or her immediately drop to the floor and roll.
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From page 90... ...
It is also important to plan for careful management of the substances throughout their life cycle from acquisition and storage through destruction or safe disposal. 5.D.2 Experiment Protocols Involving Highly Toxic Chemicals Experiment plans that involve the use of highly toxic substances or high-risk protocols should be considered carefully, and experienced personnel or an appropriate source should be consulted about the risk.
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From page 91... ...
It would be prudent to review the amounts of material to be used, the toxicological properties of the substances, the opportunity for and duration of exposure, and plans for waste disposal for any experiment plans involving highly hazardous chemicals. 5.D.3 Designated Areas Most experimental procedures involving highly toxic chemicals, including their transfer from storage containers to reaction vessels, should be confined to a designated work area in the laboratory.
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From page 92... ...
When these materials are transported, the full complement of personal protective equipment appropriate to the chemicals in question should be worn, and the samples should be carried in unbreakable secondary containers. 5.D.6 Preventing Accidents and Spills with Substances of High Toxicity Emergency response procedures must cover highly toxic substances because such procedures provide the last line of defense in working with these chemicals.
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From page 93... ...
All toxicity and emergency response information about the highly toxic chemicals being used should be readily available both before and during experimentation and should be located outside the immediate work area to ensure accessibility in emergencies. All laboratory workers who could potentially be exposed must be properly trained to participate in first aid or emergency response operations.
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From page 94... ...
5.E.Z Radioactive Materials Prudent practices for working with radioactive materials are similar to those needed to reduce the risk of exposure to toxic chemicals (section 5.C has similiar information) and to biohazards: · Know the characteristics of the radioisotopes that are being used, including half-life, types and energies of emitted radiations, the potential for exposure, how to detect contamination, and the annual limit on intake.
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From page 95... ...
General prudent practices include minimizing the amounts used, storing chemicals properly, keeping appropriate fire extinguishing equipment readily available, physically separating flammable materials from other operations and sources of ignition, properly grounding static sources of ignition, and using the least hazardous alternative available. Ignition sources should be eliminated from any area where flammable substances are handled.
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From page 96... ...
Such reactions can occur spontaneously or be initiated and can produce pressures, gases, and fumes that are hazardous. Highly reactive and explosive materials used in the laboratory require appropriate procedures.
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From page 97... ...
Careful planning is essential to avoid serious accidents. When highly reactive materials are in use, emergency equipment should be at hand.
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From page 98... ...
5.G.2. I Personal Protective Apparel When explosive materials are handled, the following items of personal protective apparel are needed: · Safety glasses that have solid side shields or goggles should be worn by all personnel, including visitors, in the laboratory.
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From page 99... ...
5.G.Z.4 Determining Reaction Quantities When a possibly hazardous reaction is attempted, small quantities of reactants should be used. When handling highly reactive chemicals, it is advisable to use the smallest quantities needed for the experiment.
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From page 100... ...
All organic peroxides are highly flammable, and fires involving bulk quantities of peroxides should be approached with extreme caution. Precautions for handling peroxides include the following: · Limit the quantity of peroxide to the minimum amount required.
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From page 101... ...
Along with observation of the precautions for the handling of gas cylinders and flammable gases, additional attention must be given to carrying out hydrogenation reactions at pressures above 1 atm. The following precautions are applicable: · Make sure that the autoclave, pressure bottle, or other apparatus is appropriate for the experiment.
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From page 102... ...
These materials should be used with adequate ventilation and should not be exposed to ignition sources. When finely divided, some solids, including zirconium, titanium, Raney nickel, lead
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From page 103... ...
Perchlorate salts of organic, organometallic, and inorganic cations are potentially explosive and have been set off either by heating or by shock. Perchlorates should not be used as drying agents if there is a possibility of contact with organic compounds or of proximity to a dehydrating acid strong enough to concentrate the perchloric acid (HC104)
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From page 104... ...
with evolution of sufficient heat to cause ignition. Carbon dioxide, bicarbonate, and carbon tetrachloride fire extinguishers should not be used on alkali metal fires.
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From page 105... ...
It may flow to ignition sources. Hydrogen selenide is an irritant to eyes, mucous membranes, and pulmonary system.
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