List of tables
Tables listed in this manual are:
The general safety and accident-prevention guidelines listed and explained in this chapter are intended to provide you with an overview of EH&S standards for UCF's laboratories.
Quick list of laboratory safety
Responsibility for laboratory safety at UCF is covered at many different levels:
1.1 University President/Board of Trustees
These entities have ultimate legal responsibility for laboratory safety and the university's compliance with the OSHA Lab Standard.
1.2 Environmental Health& Safety/ Chemical Hygiene Officer (CHO)
EH&S is responsible for coordinating laboratory safety programs at UCF. A respresentative from EH&S is appointed as the university Chemical Hygiene Officer. The CHO's duties are to maintain and update the Chemical Hygiene Plan, coordinate the process of inspecting individual laboratories to ensure lab safety and compliance with the OSHA Lab Standard.
1.3 Functional Area Manager
Each laboratory unit shall designate an individual to serve as the FAM. A laboratory unit might be a single lab, a group of research labs all under the direction of the same Principal Investigator, or a group of instructional laboratories within a single department. The FAM's shall serve as a point of contact between the laboratory personnel and EH&S.
1.4 Department Heads
Each department head has the responsibility for safety compliance for the laboratories in her/his department. This responsibility takes the form of ensuring that Principal Investigators are aware of the laboratory safety program requirements and mandating lab unit participation. Departmental safety officers or committees may serve in the delegation of this responsibility.
1.5 Principle Investigators (PI's)
PI's have the ultimate responsibility for ensuring operations conducted by persons under their supervision are planned and carried out in accordance with the CHP and to develop procedures that address unique characteristics and hazards of the individual lab.
1.6 Laboratory Personnel
Laboratory workers are responsible for following established protocols unique to their lab and to develop good personal laboratory safety and chemical hygiene habits.
This section contains guidelines for displaying, reading, and understanding hazard information to communicate the existence of hazards in the laboratory.
2.1.1. Material Safety Data Sheet (MSDS)
Understanding the Material Safety Data Sheet (MSDS) is necessary for laboratory workers to receive hazardous chemical information as specified by the OSHA Hazard Communication Standard. Under this standard manufacturers of hazardous chemicals are required to submit a detailed MSDS of every chemical they sell or distribute to their clients. Any MSDS information must always be available in the laboratory. In addition, EH&S keeps the master files of MSDS information for all of UCF
2.1.2. Hazard Warning signs
Hazard Warning signs indicate the nature of any potential hazard contained in the laboratory or storage area.
Hazard warning signs indicate:
2.1.3. Container labels
Each container in the laboratory must have a label describing the contents and the relevant hazards associated with them. Label all chemical containers, including waste containers. If mixtures are in the container, give the percentage of each hazardous chemical present in the mixture.
2.3. Health and Hygiene
Observing these practical aspects of health and hygiene can help reduce your risk of exposure to hazardous chemicals.
When doing laboratory housekeeping, make sure work areas are clean and free from obstructions. Always clean up:
Don't use aisles, hallways, and stairways for storage areas. If you run out of room for storage or you do not know where to store an item, use common sense: check with your supervisor or contact the Lab Manager.
188.8.131.52. General housekeeping guidelines
Observe these general housekeeping guidelines:
Always examine the status of containers. Replace worn-out labels with new, clearly-marked labels.
Keep the quantity of chemicals stored in the laboratory to the minimum needed for conducting experiments. Do not hoard chemicals!
2.3.1. Food and drink
No eating, drinking, or smoking is allowed in
Never store food in the laboratory!
Use the break room for storing, using, and handling food and drink.
Food, drink, smoking materials, and other consumables are potential routes-of-exposure for hazardous materials. Contact, by any method, of hazardous chemicals to items you consume can create a health risk to you and your co-workers.
Observe these practical guidelines for handling food and drink:
Observe these practical guidelines for hand washing:
Some solvents can remove several protective oils from the skin, cause irritation and inflammation, and in some cases, the solvents aid the skin in absorbing toxic material.
Never use your mouth to siphon liquids through pipettes. Always use a siphoning bulb!
Pipettes are thin glass tubes used for siphoning liquids. Use pipettes with a siphoning bulb or vacuum device to transfer chemicals.
2.3.4. Preparation for chemical spills
Chemical spills can be handled effectively if you prepare and are familiar with the proper cleanup procedures.
Preparation consists of:
Be sure spill kits are available in your laboratory. Spill kit materials include:
2.3.5. Working alone
If you are working alone or after hours, make arrangements with other persons in the building to check with each other periodically.
Experiments which are hazardous shall not be performed by a worker who is alone in a laboratory.
2.3.6. Unattended operations
Unattended operations which may continue for several hours or overnight should be approved by the laboratory supervisor.
Operations should be designed to be safe, and
plans should be made to avoid hazards in the event of a failure in power, water,
gas, or some other service. Room lights should be left on and an appropriate
warning sign should be placed on the door.
2.4. Safe Use of Equipment
The safe use of equipment is an important step in achieving a safe working environment in the laboratory.
Every refrigerator should be clearly labeled to indicate whether it is suitable for storage of flammable liquids. Flammable liquids stored in a refrigerator must be in closed containers.
Three types of refrigerators are available for use:
The common household refrigerator is not equipped with explosion-safe controls or door switches and should not be used to cool flammable liquids because sparks from controls or door switches may ignite the vapor-air mixture.
184.108.40.206. The explosion-safe refrigerator
The explosion-safe refrigerator is constructed with its controls mounted outside the storage compartment. This type refrigerator is suitable for storing flammable liquids.
220.127.116.11. The explosion-proof refrigerator
The explosion-proof refrigerator also has its controls mounted on the outside. In addition, the controls are of an explosion-proof design. This type is needed only where both the internal and external environment present a fire or explosion hazard.
2.4.2. Heating equipment
Heating equipment is divided into two types: steam-heated devices and electrically-heated devices.
18.104.22.168. Steam-heated devices
Steam-heated devices should be used whenever possible. When you use steam-heated devices, you are not at risk of electric shock or spark hazards as when using electrically-heated devices or Bunsen burners. Steam-heated devices can be left unattended with the assurance that their operating temperature will not rise beyond 100º C (212º F).
22.214.171.124. Electrically-heated devices
Do not exceed the manufacturer's recommended maximum input voltage on any electrically-heated device.
Never support an electrically-heated oil bath on an iron ring. You risk tipping the bath.
Heating mantles. Electrically-heated heating mantles must be checked frequently for broken fiberglass coating and for water or chemical spillings.
Hot plates. Electrically-heated hot plates may be used, provided they are in a glass, ceramic, metal, or other insulated case.
Oil baths. Electrically heated oil baths must be constantly monitored with a thermometer to ensure that the temperature of the bath does not exceed the flash point of the oil used. If the temperature is too high, smoking or splattering can occur:
Older electrically-heated devices can cause spark hazards because of faulty on/off switches. Report faulty wiring or frayed cords to your Lab Manager.
Burners require a heat-distribution device such as a wire gauze pad. As with all heating equipment, burners should not be left on when not in use. You should understand the hazards of burners before proceeding with an experiment.
Glassware is by its nature fragile and dangerous. Careful handling is required:
Tubing should be fire-polished or filed smooth and lubricated.
2.4.4. Chemical fume hoods
Do not store chemicals in the hood. Keep materials stored in hoods to a minimum and in a manner that will not interfere with the airflow.
Do not use the hood as a chemical disposal.
Chemical fume hoods are intended to remove vapors, gas, and dust of toxic, flammable, corrosive, or otherwise dangerous materials. Also, laboratory fume hoods can give you protection from such hazards as chemical splashes, sprays, or fires if you lower hood sashes to the indicated level of proper airflow. However, hoods are not designed to withstand explosions.
126.96.36.199. Daily operation of fume hoods
In the daily operation of fume hoods, observe these guidelines:
Using perchloric acid requires specially-designed hoods. For the specifications of a perchloric-acid fume hood, contact EH&S.
2.4.5. Hazards of particular equipment
For your safety and for the safety of others, you should be aware of hazards of particular equipment in handling, processing, or transporting chemicals.
188.8.131.52. Liquid-nitrogen-cooled traps
Liquid-nitrogen-cooled traps, when open, rapidly condense liquid from the air. Subsequently, when the coolant is released, an explosive pressure buildup occurs, usually with enough force to shatter glass equipment. Therefore, only sealed or evacuated equipment should be cooled.
184.108.40.206. Vacuum distillations
Residues from vacuum distillations (from example, ethyl palminate) have been known to explode when the still was vented to air before the residue cooled. To prevent explosion, do one of three things: vent the still pot with nitrogen, cool the still before venting, or restore the pressure slowly.
2.5. Disposal of Hazardous Chemical Waste
In UCF laboratories, disposal of hazardous chemical waste is regulated by federal agencies. A review of the properties of hazardous chemical waste, the federal regulations, and waste disposal procedures are discussed in this section. Also, see Chapter 5: Chemical Safety in this manual.
2.5.1. Definition of hazardous chemical waste
Hazardous chemical waste is defined as having one or more of these characteristics:
Ignitable -- a flash point of less than 194.4ºC (140ºF)
If you are not sure whether your chemical waste is considered to be hazardous, contact your Lab Manager or call EH&S.
2.5.2. Resource Conservation and Recovery Act (RCRA)
The Federal Resource Conservation and Recovery Act (RCRA) was devised with the mission to promote the protection of the environment and of human health. A tracking system for hazardous chemical wastes has been developed in order to accomplish this mission. The system has an approach known as the cradle-to-grave system -- that is, hazardous chemical wastes are tracked from the place of production to the place of disposal.
The Environmental Protection Agency (EPA) and the Department Of Transportation (DOT) have produced the regulations for hazardous wastes. The EPA and DOT require that all materials that are, or have the potential to be, hazardous chemical wastes be specifically identified.
Principal investigators have the responsibility for proper handling and storage of hazardous chemical wastes in the laboratories.
2.5.3. Collection of hazardous chemical waste
EH&S is responsible for the collection of hazardous chemical waste from each laboratory and arranging for shipment to a hazardous waste management facility as approved by the Environmental Protection Agency (EPA). To notify EH&S about a waste pick-up, use the Hazardous Chemical Transport Manifest. See Figure 2.6 on page 30 for a copy of the Manifest.
The principal investigator is responsible for seeing that all hazardous chemical waste is correctly and permanently labeled.
Observe these guidelines:
For further details on hazardous chemical waste procedures, see the UCF Environmental Management Work Practices for Laboratory Operations.
When dealing with a spill, never mix halogenated solvents with non-halogenated solvents.
EH&S cannot accept unlabeled or generically-labeled chemicals (example: titration waste), and wastes in improper containers.
Always keep wastes in containers appropriate for the chemical constituents involved, and always use containers with good, quality seals.
Only when a fire presents an immediate life-threatening situation should you fight the fire.
For a fire to occur, a triangle of three
elements -- fuel, oxidizer, and ignition source -- have to be present.
Preventative measures described in this manual can help keep fire from occurring
by removing one or more of the elements from the work area. Once a fire is
ignited the fuel proceeds through a series of chemical reactions until it is
converted to the final products of burning. Fire fighters call the combinations
that influence ignition the fire triangle. See Figure 2.7 below for an example
of the fire triangle.
2.6.1. Fire Prevention Procedures For Laboratories With Chemicals (NFPA 45 Standard)
This standard and its procedures were developed by the National Fire Protection Agency (NFPA). They apply to all teaching, research, or contract laboratories which use chemicals, except:
Maintain all laboratories as No Smoking areas. Place signs to visibly mark these areas.
220.127.116.11. General chemical hazards
Place signs explaining the nature of chemical hazards contained in the laboratories. Ensure that these signs are visible at the entrance doors to each laboratory.
18.104.22.168. General labels
Label all chemicals clearly with both the chemical name and the nature of any hazards common to that chemical. Include special protection information if possible.
Isolate hazardous chemicals and store as to hazard types:
Ensure that flammable chemicals are stored only in UL-listed, flammable-rated storage cabinets, gas cans, or refrigerators
22.214.171.124. Explosives and reactives
Ensure that all explosives or pyrophoric reactives are stored only in UL-listed explosion-proof refrigerators or containers.
126.96.36.199. Compressed gas cylinders
Ensure that all compressed gas cylinders are stored in a safe location and chained. Cylinders must be capped when not in use.
188.8.131.52. Warnings for flammable chemicals or gases
Use these warning signs or labels for flammable chemicals or gases:
Ensure that a responsible person is assigned to periodically check out and inspect laboratory equipment. Equipment includes items such as Bunsen burners, electrical appliances, hot plates, and electrical cords.
184.108.40.206. Gas valves and pipelines
Before restoring gas after a shutdown:
All gas valves and stopcocks must be checked and turned off!
Always shut off gas valves after use. Make sure that all piping and line connections are free from damage, defect, or flaw. In addition:
Chemical safety means personal safety. Review this chapter carefully. If you would like more details on specific aspects of chemical safety, contact EH&S.
Safety and emergency equipment is intended to protect you from injury if a serious incident occurs. Properly used, safety and emergency equipment can reduce the exposure to injury caused by chemicals, broken glass, burning materials, fires, and other causes.
Signs posted in sections of the labs will help you to quickly find the locations of safety showers, eyewash stations, exits, and fire extinguishers.
For your safety, know the locations of, and how to use safety and emergency equipment. Become familiar with emergency procedures!
This chapter reviews emergency procedures that are discussed in more detail in the UCF Emergency Management Plan see http://www.ehs.ucf.edu/emergency/emergencyplan.html
Reporting an emergency: quick-reference
Call Police / Medical: 911
When reporting an emergency, include if possible:
Condition of any injured people (unconscious, burned, trapped)
Type of fire (if there is one).
Shock is a dangerous condition and can be fatal. Expect some degree of shock in any emergency. DO NOT move seriously-injured people unless they are in danger of further injury. Stay on the line if requested by the operator.
3.2. First Aid Treatment
This section deals with procedures for dealing with laboratory accidents.
3.2.1. Chemical spills on the body
Do not use neutralizing chemicals or salves on body parts affected by a chemical spill!
If chemicals have been spilled over a large area of the body:
Quickly remove all contaminated clothing while using the safety shower. Immediately flood the exposed areas with cold water for at least 15 minutes. Resume if pain returns. Wash off chemicals by using a mild detergent or soap and water.
If chemicals have been spilled on a confined area of the skin:
Immediately flush with cold water. Remove any jewelry in the affected area. If a delayed action of the chemical is possible, obtain medical attention promptly.
Examples of chemicals harmful to the skin: ethyl bromide, hydrochloric acid, methyl bromide, and sodium hydroxide.
3.2.2. Chemicals in the eyes
If a chemical has been splashed into the eyes, wash out the eyes and inner surface of the eyelids with lots of water for 15 minutes.
Use an eyewash fountain, if available. Place the injured person on the back, hold the eyes open, and gently pour water into the eyes. If an eyewash fountain is not available, use the nearest available sink or spigot.
If professional help cannot be reached immediately, call 911, request the poison control center, and follow their instructions.
If poisoning is suspected:
If the victim is conscious:
Do encourage the victim to drink water or milk immediately to dilute poison. At the same time call 911 and ask for the Poison Control Center for professional medical help. Describe the poisonous substance and the victim's condition. Ask for first aid instruction
Do administer any antidote recommended by Poison Control Center as soon as possible.
If the victim is unconscious, having convulsions, becomes nauseated or vomits:
Don't force fluids
Don't give any other first aid if the victim is unconscious or is having convulsions
Do get professional medical assistance. Apply rescue breathing techniques or CPR if necessary. If the victim is convulsing, protect from injury; loosen tight clothing if possible.
220.127.116.11. Vomiting poisons
Follow these guidelines for vomiting poisons:
Do not Induce vomiting if the poison is
A corrosive substance (acid, cleaning fluid, lye, drain cleaner)
A petroleum product (gasoline, turpentine, paint thinner, lighter fluid)
Activated charcoal is used to absorb poisons in these situations.
Induce vomiting if the poison is known and is not a corrosive substance or petroleum product.
To induce vomiting:
Give an adult one ounce of syrup of ipecac (1/2 ounce for a child) followed by four or five glasses of water. If vomiting does not occur, repeat this procedure in 20 minutes
After the victim has vomited, follow with one ounce of powdered, activated charcoal in water, if available
Take the poison container (or vomitus if poison is unknown) with the victim to a hospital.
3.2.4. Burns and scalds
If the clothing is on fire, do not let the person run. Running only fans the flames and intensifies the fire.
Help the individual to the floor and roll the person around to smother the flames
If a safety shower is immediately available, douse the person with water.
DON'T attempt to clean the burn or break blisters.
DON'T remove any clothing that sticks to burn.
DON'T apply grease, ointment, or medication to a severe burn.
DON'T use cotton or material with loose fibers to cover burns.
18.104.22.168. First degree burns
First degree burns -- redness or discoloration of skin surface; mild swelling and pain.
For treating first degree burns:
Apply cool, wet cloths or immerse in cool water. Do not use ice
Blot gently; apply a dry, sterile pad if necessary
Usually medical treatment is not necessary.
However, if severe symptoms exist, call for professional medical help. Be alert
for signs of shock.
22.214.171.124. Second degree burns
Second degree burns -- deep burn with red or mottled appearance; blisters; considerable pain and swelling; skin surface appears wet.
For treating second degree burns:
See treatment for first degree burns
In addition, if arms and legs are affected, elevate them above heart level. Burns may be deep and potentially serious requiring medical treatment depending on extent and location. Be alert for signs of shock and infection.
126.96.36.199. Third degree burns
Call for medical assistance immediately. Be alert for signs of shock.
Third degree burns -- deep tissue destruction with a white or charred appearance; no pain.
For treatment of bleeding, act quickly:
Call for professional help immediately: call 911
Have victim lie down. Do not give the victim anything by mouth!
Elevate the injured limb higher than heart unless you suspect a broken bone
Control bleeding by applying direct pressure on the wound with a sterile pad or clean cloth
If bleeding is controlled by direct pressure, bandage firmly to protect wound. Check pulse to be sure bandage is not too tight
If bleeding is not controlled by use of direct pressure, apply a tourniquet only as a last resort
Call for professional help if you didn't do Step 1.
If you are bleeding and have no one to help you, call for professional medical help. Lie down, so your body weight applies pressure to the bleeding site.
3.2.6. Step-by-step wound care method to help prevent infection
Following this step-by-step wound care method can help prevent infection to injuries. When possible, wash hands thoroughly with soap and water before administering first aid.
4.1. Fire Extinguishers
Fire extinguishers are required by National Fire Protection Association (NFPA) and OSHA regulations. In general, the regulations state that:
After reviewing this section, if you have any further questions regarding fire extinguishers for your lab, contact EH&S.
4.1.1. Types of fires and fire extinguishers
The type of extinguisher that needs to be available is based upon two factors:
188.8.131.52. Water extinguishers
Water is effective against burning paper, cotton and wood fibers, and paper trash.
Never use water on Class C electrical fires. You are at risk of electric shock if you use water on live electrical equipment.
Water's ability to extinguish Class A fires rests on its ability to cool the fuel and exclude oxygen. That is to say, water can remove two elements from the fire triangle discussed in section 2.6. More specifically, water excludes, or dilutes, oxygen by the formation of steam. Its high heat capacity accounts for its cooling ability.
Advantages. Water has two advantages as a Class A extinguisher:
Water worsens Class B fires because most fuels have a density less than that of water
The fuel will float on top of the water and spread as the water flows to the lower levels
While floating on the water's surface, the fuel's oxygen supply is not disturbed nor is the fuel cooled
Water cannot be used on Class D fires because of the chemical reactions -- specifically oxidations -- which can occur between water and the metal.
184.108.40.206. Carbon dioxide extinguishers
Carbon dioxide is suggested for fires involving delicate instruments and optical systems.
Never use carbon dioxide extinguishers against fires caused by lithium aluminum hydride or potassium.
Carbon dioxide extinguishes Class B and C fires by depleting oxygen and cooling the fuel.
Advantages. Carbon dioxide has several advantages:
Dry chemical monoammonium phosphate (MAP) extinguishers can be used for Class A, B, and C fires.
The dry chemical monoammonium phosphate (MAP) extinguisher, also called the ABC or all-purpose extinguisher, is a broad-ranged extinguisher. The MAP's diversity contributes to the fact it is the type most often found in homes and cars. The MAP extinguisher is suitable for Class A, B, and C fires. Do not use it on organic metal (Class D) fires.
Advantages. The MAP extinguishers have the same advantage as carbon dioxide extinguishers in that they smother the fire and choke off the oxygen supply. This advantage makes MAP extinguishers ideal for use on virtually any material except organic metals.
Disadvantages. However effective, the MAP extinguishers have some disadvantages:
Dry chemical potassium or sodium carbonate extinguishers are effective against burning grease and oil.
If you are using a coolant to prevent flare-ups in a fire extinguished by dry chemicals:
Turn off or disconnect all electrical equipment!
These dry chemical extinguishers are like MAP extinguishers except that they contain either potassium or sodium carbonate as the extinguishing agent. They can be used on Class B and C fires, but not Class A nor Class D fires.
Advantages. Potassium or sodium bicarbonate extinguishers smother burning grease much faster and more certainly than the MAP extinguisher can. The potassium or sodium bicarbonate interferes with the clumping of fats and oils.
Disadvantages. One chief disadvantage is the sticky residue, which, like the MAP extinguisher, presents the same problems when used on electrical equipment. Also, potassium or sodium bicarbonate extinguishers can have the same problems as the MAP extinguisher in requiring an additional coolant.
220.127.116.11. Halon-gas extinguishers
Halon-gas (halon) extinguishers are effective against electrical fires without causing low-temperature stress effects to electronic equipment.
Halon can be used for Class B and C fires. It is somewhat less effective with Class A fires (see Disadvantages below). Do not use halon on a Class D fire.
Halon-gas (halon) extinguishers put out fires by choking off oxygen. The halon gas is a non-reactive chlorofluorocarbon.
18.104.22.168. Extinguishers for Class D fires
Extinguishers for Class D fires are specially-formulated to treat organic and alkali metals that cannot be safely extinguished by other fire extinguisher agents.
Never use a Class D-rated extinguisher for Class A, B, or C fires. See the guidelines below.
Class D fires are caused by ignition of organic metals such as lithium (an alkali metal), aluminum, or sodium. Class D fires are particularly troublesome to extinguish because of the intensity with which they burn and their ability to react chemically with normal extinguishing agents. As an example, carbon dioxide will not react with cold sodium but accelerates the burning rate of ignited sodium. Two agents that are used to extinguish Class D fires are sand and sodium chloride.
Guidelines. To extinguish Class D fires:
4.2. Safety Showers and Eyewash Stations
A safety shower and eyewash station must be located within 10 seconds travel of the hazard. Every laboratory worker should know the location of, and how to use the safety shower and eyewash station in order to be able to locate it with eyes closed, if necessary.
4.4. Protective Equipment and Clothing
Always make sure that you use protective equipment and clothing in order to anticipate any accident, no matter how slight the danger.
4.4.1. Eye protection
Do not wear contact lenses in the laboratory if there is a risk of the lenses:
Reacting with lab chemicals
Being damaged by lab chemicals.
Specific goggles for protection against laser hazards, ultraviolet, or other intense light sources must be worn without exception.
Eye protection must be worn at all times in all laboratories when working with chemicals, conducting an experiment, or using special machinery. Eye protection is not required when conducting an instrumental study.
Prescription glasses will not always provide adequate protection from injury to the eyes. The minimum acceptable protection is hardened glass or plastic safety glasses.
Use safety goggles or face shields of hardened plastic or safety glass. They acceptable eye protection for preventing splashing chemicals, flying particles, or other products of violent chemical reactions from getting into your eyes.
Gloves made for skin protection must be worn when working with toxic/corrosive materials or with materials of unknown toxicity. Gloves should be selected on the basis of material being handled and their suitability for the particular laboratory operation. See your Lab Manager or EH&S for chemical compatibility and protection information.
Footwear must be worn at all times in the laboratory. Solid-toes shoes are the only type of footwear accepted in the labs. Open-toed shoes are prohibited. They do not protect against glass or spilled chemicals.
4.4.4. Unacceptable clothing
Do not wear loose, skimpy, or torn clothing,
dangling neckties, over-large or ragged laboratory coats, shorts or halter tops.
Laboratory clothing should protect yourself. If there is a possibility of
contamination, cover personal clothing that will be worn home with protective
5.1. Chemical Storage Guidelines
Storing chemicals requires some thought and common sense. Many accidents that result from chemicals are caused by people being unfamiliar with storage procedures or being carelessly negligent. Observe these guidelines for storage after you receive chemicals:
Don't store flammables in unapproved refrigerators. See Section 4.4.1.
5.1.1. Storing chemicals at the lab bench
Limit storage of chemicals at the lab bench or other work areas to those amounts necessary for one operation or shift. The container size shall be the minimum convenient. The amounts of chemicals at the lab bench shall be as small as practical. Do not expose chemicals in the workplace to sunlight or heat.
Do not use the storage area as a preparation or repackaging station.
Transportation of chemicals presents a potential danger to you or to other workers, and that danger can extend to the general public. Observe these guidelines for transporting chemicals:
Lab personnel must examine stored chemicals regularly for replacement, deterioration, and container integrity. The inspection can determine whether any corrosion, deterioration, or damage has occurred to the storage facility as a result of leaking chemicals.
Online chemical inventory must be updated as new chemicals are procured and existing chemicals are disposed or depleted.
5.3. Chemicals With Specific Properties
The guidelines listed below cover handling procedures and safety precautions for chemicals with specific properties.
5.3.1. Flammable liquids
Never smoke near flammable liquids!
Never use an open flame near flammable liquids!
Flammable liquids are the most common of hazardous substances found in the laboratory. The ability of a liquid to vaporize, ignite, burn, or explode varies depending on its flash point. A flash point is the temperature at which a liquid gives off vapor in sufficient concentration to form an ignitable mixture with air. The solvent will not ignite below nor above the flash point.
When flammable materials are being used in a laboratory, close attention should be given to all potential sources of ignition. The vapors of all flammable liquids are heavier than air and capable of traveling considerable distances. Take special note that the ignition sources of flammable materials are usually closer to the ground than the level at which the flammable substance is used.
Observe these guidelines when handling flammable liquids:
Transfer flammable liquids carefully. The friction of flowing liquids may be sufficient to generate static electricity which in turn can cause a spark and ignition. Therefore, ground or bond all such large containers before pouring from them.
22.214.171.124. Flash point information
Flash point information is usually available on the label attached to the chemical container, on the MSDS, or in tables. Flammable liquids are those with flash points below 37.7ºC (100º F). Combustible liquids have flash points between 37.7 and 93.3ºC (100 and 210ºF).
Among the most hazardous liquids are those that have flash points at room temperature or lower, particularly if their range of flammability is broad. For a fire to occur, three conditions must exist:
Table 1: Flammability data of common laboratory
|CHEMICAL||CLASS||FLASH POINT||BOILING POINT||IGNITION TEMPERATURE||FLAMMABLE LIMITS [by volume in air]|
|Acetaldehyde||1A||-37.8º||21.1º||175.0º||4.0 %||60.0 %|
|Acetone||1B||-17.8º||56.7º||465.0º||2.6 %||12.8 %|
|Benzene||1B||-11.1º||80.0º||560.0º||1.3 %||7.1 %|
|Carbon Disulfide||1B||-30.0º||46.1º||80.0º||1.3 %||50.0 %|
|Cyclohexane||1B||-20.0º||81.7º||245.0º||1.3 %||8.0 %|
|Diethyl Ether||1A||-45.0º||35.0º||160.0º||1.9 %||36.0 %|
|Ethyl Alcohol||1B||12.8º||78.3º||365.0º||3.3 %||19.0 %|
|h-Heptane||1B||- 3.9º||98.3º||215.0º||1.05 %||6.7 %|
|h-Hexane||1B||-21.7º||68.9º||225.0º||1.1 %||7.5 %|
|Isopropyl Alcohol||1B||11.7º||82.8º||398.9º||2.0 %||12.0 %|
|Methyl Alcohol||1B||11.1º||64.9º||385.0º||6.7 %||36.0 %|
|Methyl Ethyl Ketone||1B||- 6.1º||80.0º||515.6º||1.8 %||10.0 %|
|Pentane||1A||-40.0º||36.1º||260.0º||1.5 %||7.8 %|
|Styrene||1B||32.2º||146.1º||490.0º||1.1 %||6.1 %|
|Toluene||1B||4.4º||110.6º||480.0º||1.2 %||7.1 %|
|p-Xylene||1C||27.2º||138.3º||530.0º||1.1 %||7.0 %|
126.96.36.199. Storage of flammable liquids
The following guidelines should be observed in the storage of flammable liquids:
An ordinary five-gallon container does not provide adequate protection in cases of fire.
An approved safety can with a self-closing cover, vent, and flame arrester is the best container for storing flammable liquids or waste solvents in small quantities.
Table 2: Flammable liquids -- maximum size of
|CONTAINER TYPE||CLASS 1A LIQUIDS||CLASS 1B LIQUIDS||CLASS 1C LIQUIDS|
|Glass (see Note below)||1 pint||1 quart||1 gallon|
|Approved Metal or Plastic||1 gallon||5 gallons||5 gallons|
|Safety Cans||2 gallons||5 gallons||5 gallons|
|Metal Drums (ICC Specifications)||60 gallons||60 gallons||60 gallons|
|Class 1A -- Flash
point below 73 F. Boiling point below 100 F. Class 1B -- Flash point below
73 F. Boiling point at or above 100 F. Class 1C -- Flash point at or above
73 F, and below 100 F.
NOTE Exceptions may be made to regulations for glass for storage of Class 1A and Class 1B liquids up to 1 gallon, but you must ask EH&S for permission first.
Table 3: Flammable liquids -- maximum quantities
|In the laboratory||10 gallons||Observe the flash points and boiling points shown in Table 2 above.|
|In safety cans in the laboratory||25 gallons||Observe the flash points and boiling points shown in Table 2 above.|
|In a fire-rated storage cabinet||50 gallons||No conditions specified.|
5.3.2. Toxic materials
Before you start work with a chemical substance, you (the researcher or laboratory person) should be familiar with certain aspects of the chemical, particularly:
Toxicity is the capability of a chemical to induce injury in a body. Almost any substance is toxic when taken in doses exceeding tolerable limits.
Hazard is the probability that an injury will occur or the chance that a person will be exposed to a toxic dose.
The effects of a toxic chemical may be sorted into several categories:
Inhalation of toxic vapors, mists, gases, or dusts can result in poisoning by absorption through the mucous membranes of the mouth, throat, and lungs and can cause serious effects. Lungs have a large surface area: a total surface area of 90 square meters. This large surface area, along with continuous blood flow, will rapidly absorb inhaled gases or vapors and carry them into the circulatory system.
The rate of absorption will vary with the concentration of the toxic substance, its solubility, and the individual inhalation rate. The degree of injury from exposure to a toxic substance depends on the toxicity of the material, its solubility in tissue fluids, and the concentration and duration of exposure.
Table 4: Combined tabulation of toxicity classes
|COMMONLY USED TERM||LAB TESTS||COMPARATIVE LETHAL DOSE LEVELS FOR HUMANS|
|LD50 SINGLE ORAL DOSE FOR RATS||4-HOUR VAPOR EXPOSURE CAUSING 2-4 DEATHS IN 6-RAT GROUPS||LD50 EXPOSURE ON THE SKIN FOR RABBITS|
|SINGLE ORAL DOSE FOR RATS||LD50 EXPOSURE ON THE SKIN|
|grams per kilogram (g/kg)||parts per million (ppm)||grams per kilogram (g/kg)|
|Extremely toxic||0.001 or less||10.0 or less||0.005 or less||Taste (1 grain)|
|Highly toxic||0.001 - 0.05||10.0 - 100.0||0.005 - 0.043||1 teaspoon (4 cc)|
|Moderately toxic||0.05 - 0.5||100.0 - 1,000.0||0.044 - 0.340||1 ounce (30 grams)|
|Slightly toxic||0.5 - 5.0||1,000.0 - 10,000.0||0.35 - 2.81||1 pint (250 grams)|
|Practically nontoxic||5.0 - 15.0||10,000.0 - 100,000.0||2.82 - 22.6||1 quart|
|Relatively harmless||15.00 or more||100,000.0 or more||22.6 or more||1 quart or more|
Ingestion of chemicals used in the laboratory can result in significant bodily injury. The relative acute toxicity of a chemical can be determined by its oral Lethal Dose 50% (oral LD50). An oral LD50 is the quantity of material ingested that will cause 50% of test animal deaths. Oral LD50 is usually expressed in milligrams per kilogram of body weight (mg/ kg body weight).
To prevent ingestion of chemicals:
Two other ways of ingestion are through contact with skin or eyes.
Skin contact. Skin contact is the most frequent route of exposure to chemical substances. A common result of skin contact is local irritation. But, some materials can be absorbed sufficiently through the skin to cause systemic poisoning.
To protect against skin contact with chemicals, use gloves, laboratory coats, tongs, and other protective devices. Consult chemical resistance charts for determining what types of clothing and materials resist the corrosive actions of specific chemicals.
Eye contact. Eye contact with most chemicals will result in pain and irritation. The vascular network of the eyes permits rapid absorption of many chemicals. And, a considerable number of chemical substances are capable of causing burns or vision loss. Alkaline substances are particularly corrosive and can cause permanent vision loss.
To prevent eye contact with chemicals, you should always wear safety glasses in the laboratory. For even better protection than safety glasses, use face shields, body shields, or safety goggles.
With these aspects in mind, be sure to thoroughly check your experimental procedure before you begin. If you are not sure about a chemical or procedure, contact your Lab Manager or call EH&S. Either contact can help you plan your experiments with toxic chemicals by providing up-to-date safety information.
5.3.3. Particularly dangerous acids
Certain acids are particularly dangerous in concentrated form:
Nitric acid is a corrosive, flammable oxidizer. It can produce flammable and explosive compounds with many materials: ethers, acetone, and other combustible materials. Paper used to soak up nitric acid may ignite spontaneously when dry. Use nitric acid in a hood only. Store nitric acid away from combustible materials.
188.8.131.52. Perchloric acid
Do not keep perchloric acid for more than one year. Explosive crystals can form in the acid.
Perchloric acid forms highly explosive, unstable compounds with many organic compounds and with metals. Unstable perchlorate compounds can collect in the duct work of fume hoods and cause fire or violent explosions.
Observe these guidelines when using perchloric acid:
Picric acid can form explosive compounds with many combustible materials. When the moisture content decreases, picric acid can become unstable and can explode from being shaken also. Date the container of picric acid and store it away from combustible materials. Do not store picric acid for more than one year.
184.108.40.206. Hydrofluoric acid (HF)
Hydrofluoric acid (HF) is extremely corrosive and can even attack glass. All forms -- diluted or concentrated solutions of the vapor -- can cause serious burns. Inhalation of hydrofluoric acid mists or vapors can cause you to suffer serious respiratory tract irritation which can be fatal. Burns from hydrofluoric acid heal slowly and with great difficulty.
Hydrofluoric acid must always be used in a suitable, functioning fume hood.
Use gloves, eye protection, and a lab coat when handling the acid.
Take care to avoid contacting hydrofluoric acid with metals or ammonia. Toxic fumes can result from this contact.
Always store hydrofluoric acid in the original, Teflon-lined containers in which it was purchased.
5.3.4. Peroxides and peroxide-forming substances
In general, peroxides are among the most hazardous of substances handled in the laboratory. Organic peroxides are particularly sensitive and unstable. They are a class of compounds that have unusual stability problems. This instability makes them among the most hazardous substances handled in laboratories.
As a class, organic peroxides are considered to be powerful explosives. They are sensitive to heat, friction, impact, and exposure to light. In addition, organic peroxides are sensitive to strong oxidizing and reducing agents. All organic peroxides are flammable. Examples of organic peroxides are:
Observe these safety guidelines when using peroxides:
Table 5: Common compounds that form peroxides
|Chlorobutadiene (Chloroprene)||Methyl i-butyl ketone|
|Divinyl acetylene||Vinyl acetate|
|Ethyl ether||Vinyl acetylene|
|Ethylene glycol dimethyl ether||Vinyl chloride|
|Isopropyl ether||Vinylidene chloride|
|1||Ethers and acetals.|
|2 Olefins with allylic hydrogen, chloroolefins and fluoroolefins, terpenes, and tetrahydronaphi-thalene.|
|3 Dienes and vinyl acetylene.|
|4 Vinyl Monomers.|
|5 N/A 1 Potassium.|
|6 N/A 1 Alkali metal alkoxides and amides, and sodamide.|
|7 Paraffinic and alkylaromatic hydrocarbons, particularly those with tertiary hydrogen.|
|8 N/A 1 Grignard reagent.|
|9 Aldehydes and ketones. NOTE Anhydrous acetaldehyde with ultraviolet-light catalysis forms peracetic acid. This combination will chain-react with more acetaldehyde to produce the explosive acetaldehyde monoperacetate.|
|1 N/A: Structure not available.|
|C = Carbon / H = Hydrogen / O = Oxygen|
Corrosives consist of four major classes:
220.127.116.11. Storage and use of corrosives
When mixing or diluting solutions, do not pour water into acids. The correct procedure is:
Pour acids -- slowly -- into water.
In storing and using corrosives, observe these guidelines:
Store acids and alkalis:
Highly-reactive chemicals and explosives require special care. Certain chemical reactions are considered safe because the reaction rate is either relatively slow or can be easily controlled. However, certain reactions proceed at such a fast rate and generate so much heat that, if left uncontrolled, they result in explosion. Oxidizing agents present fire and explosion hazards on contact with organic compounds and other oxidizable substances.
Reactives are unstable materials that:
In the storage and use of oxidizing agents, observe these guidelines:
Dehydrating agents include:
18.104.22.168. Storage and use of dehydrating agents
Always store dehydrating agents in a corrosion-resistant cabinet in a cool dry place.
5.3.8. Organic metals
Organic metals are divided into two classes:
Use only special, Class D, dry powder fire extinguishers specifically designed for alkali metals on alkali metal fires.
Alkali metals such as sodium and potassium react violently with water. The metal decomposes the water back into oxygen and hydrogen. The hydrogen can ignite from the heat of the reaction.
Also, alkali metals can ignite spontaneously in air, especially if one or both of these conditions are present:
Store alkali metals under mineral oil or kerosene. Avoid using oils containing sulfur since a hazardous reaction can occur
Use care when disposing alkali metal waste:
Place alkali metal waste in a labeled, leak-proof container
Cover with mineral oil
Contact EH&S for waste pickup service.
22.214.171.124. Metal powders
Metal powders are as the name implies: finely ground metal in a powdered form. Metal powders can create certain hazards:
Cryogenics are materials that are supercooled. Cryogenic materials have certain hazards:
Observe these guidelines for storing and using cryogenics:
Observe the following rules when using compressed-gas cylinders:
Do not use color codes to label cylinders.
Colors can cause confusion, especially to someone who is color-blind.
5.4. Radioactive materials
Radioactive materials are liquids and solids that spontaneously emit Alpha, Beta, or Gamma radiation. Radioactive materials require special lab procedures and laboratory supervision.
Radiation, both in natural form and from laboratory chemicals (radioisotopes), can cause a variety of adverse health effects in humans and living animals. When handling radioactive materials , you must always work under the supervision of a competently-trained person registered with EH&S. Consult the UCF Radiation Safety Manual
Consult EH&S if you need to work with
5.5. Biological Hazards
Certain laboratory materials can be hazardous by being a biological hazard, an infectious disease hazard, or an etiological agent. These hazards require special equipment, laboratory procedures, and waste procedures.
Examples: chronic toxins, embryo-tetrotoxins, and etiological agents. Etiological agents are a variable micro-organism or its toxin which causes human disease.
Please consult the EH&S Biological Safety Guidebook for information and for more detailed biological safety measures than described here.
OSHA's Bloodborne Pathogens Standard requires
all laboratories handling biologically-hazardous chemicals to have an exposure
control plan specific to these hazards.
5.6. Other Hazardous Materials
Hazardous materials, as discussed in the previous sections of this chapter, are defined as chemicals with National Fire Protection Association (NFPA) 704 ratings of 2 or greater in: health, flammability, or instability. For more information on NFPA ratings, visit http://www.ehs.ucf.edu/chemical/704_ratings.pdf
5.6.1. Incompatible hazardous materials
Certain combinations of chemicals are particularly dangerous and should be avoided. The properties of hazardous materials determine what precautions to take for individual chemicals. See Table 7 beginning on the next page for a quick review of incompatible chemicals. Use this table when planning storage arrangements. Also, use this table to avoid storing incompatible chemicals together.
Table 7: Incompatible Chemicals
|1||Acetic acid||Chromic acid, nitric acid, hydroxyl compounds, ethylene glycol, perchloric acid, peroxides, permanganates.|
|2||Acetylene||Chlorine, bromine, copper, fluorine, silver, mercury.|
|3||Acetone||Concentrated nitric and sulfuric acid mixtures.|
|4||Alkali||Water, carbon tetrachloride and other chlorinated hydrocarbons, halogens, carbon dioxide.|
|5||Alkaline earth metals||Water, carbon tetrachloride and other chlorinated hydrocarbons, halogens, carbon dioxide.|
|6||Ammonia (anhydrous)||Mercury, chlorine, calcium hypochlorite, iodine, bromine, hydrofluoric acid (anhydrous).|
|7||Ammonium nitrate||Acids, powdered metals, flammable liquids, chlorates, nitrates, sulfur, finely-divided organic materials, finely-divided combustible materials.|
|8||Aniline||Nitric acid, hydrogen peroxide.|
|9||Arsenical metals||Any reducing agent.|
|11||Bromine||Ammonia, acetylene, butadiene, butane, methane, propane and other petroleum gases, hydrogen, sodium carbide, benzene, finely-divided metals, turpentine.|
|13||Carbon (activated)||Calcium hypochlorite, all oxidizing agents.|
|15||Chlorates||Ammonium salts, acids, powdered metals, sulfur, finely-divided organic materials, finely-divided combustible materials.|
|16||Chromic acid||Acetic acid, naphthalene, camphor, glycerol, alcohol, flammable liquids.|
|TABLE 7 continued|
|17||Chromium trioxide||Acetic acid, naphthalene, camphor, glycerol, alcohol, flammable liquids.|
|18||Chlorine||Ammonia, acetylene, butadiene, butane, methane, propane and other petroleum gases, hydrogen, sodium carbide, benzene, finely-divided metals, turpentine.|
|19||Chlorine dioxide||Ammonia, methane, phosphine, hydrogen sulfide.|
|20||Copper||Acetylene, hydrogen peroxide.|
|23||Flammable liquids||Ammonium nitrate, chromic acid, hydrogen peroxide, nitric acid, sodium peroxide, halogens.|
|24||Fluorine||INCOMPATIBLE WITH ANY MATERIAL.|
|25||Hydrocarbons||Fluorine, chlorine, bromine, chromic acid, sodium peroxide.|
|26||Hydrocyanic acid||Nitric acid, alkali.|
|27||Hydrofluoric acid (anhydrous)||Ammonia -- aqueous or anhydrous.|
|28||Hydrogen||Iodine, flammable liquids, combustible materials.|
|29||Hydrogen peroxide||Copper, chromium, iron, most metals and their salts, alcohols, acetone, organic materials, aniline, nitromethane, combustible materials.|
|30||Hydrogen sulfide||Fuming nitric acid, oxidizing gases.|
|31||Hypochlorites||Acids, activated carbon.|
|32||Iodine||Acetylene, hydrogen, ammonia.|
|33||Mercury||Acetylene, fulminic acid, ammonia.|
|35||Nitric acid (concentrated)||Acetic acid, aniline, chromic acid, hydrocyanic acid, hydrogen sulfide, flammable liquids, flammable gases, copper brass, heavy metals.|
|37||Nitroparaffins||Inorganic bases, amines.|
|TABLE 7 continued|
|38||Oxalic acid||Silver, mercury.|
|39||Oxygen||Oils, grease, hydrogen, flammable liquids, flammable solids, flammable gases.|
|40||Perchloric acid||Oils, grease, acetic anhydride, bismuth and its alloys, alcohol, paper, wood.|
|41||Peroxides, organic||Acids -- organic or mineral.|
|42||Phosphorous (white)||Oxygen, alkalis, reducing agents.|
|43||Potassium||Carbon tetrachloride, carbon dioxide, water.|
|44||Potassium chlorate||Sulfuric acid and other acids.|
|45||Potassium perchlorate||Sulfuric acid and other acids.|
|46||Potassium permanganate||Glycerol, ethylene glycol, benzaldehyde, sulfuric acid.|
|48||Silver||Acetylene, oxalic acid, tartartic acid, ammonium compounds, fulminic acid.|
|49||Sodium||Carbon tetrachloride, carbon dioxide, water.|
|50||Sodium nitrite||Ammonium nitrite and other ammonium salts.|
|51||Sodium peroxide||Ethyl or methyl alcohol, glacial acteic acid, acetic anhydride, benzaldehyde, carbon disulfide, glycerin, ethylene glycol, ethylacetate, methyl acetate, furfural.|
|53||Sulfuric acid||Potassium chlorate, potassium perchlorate, light metals -- sodium, lithium, potassium permanganate, and so on.|
5.6.2. Specific hazardous materials
These sections give brief health and safety information on specific hazardous materials.
126.96.36.199. Acetylenic compounds
Acetylenic compounds are explosive mixtures with combinations with air ranging from 2.5% to 80%.
At pressures of 2 or more atmospheres, acetylene (C2 H2) subjected to an electrical discharge or high temperatures decomposes with explosive violence. Dry acetylides detonate on receiving the slightest shock.
188.8.131.52. Aluminum Chloride (AlCl3)
Aluminum chloride (AlCl3) should be considered a potentially dangerous material. It reacts violently with water or alcohols. If any moisture is present, decomposition products such as HCI vapor can build up considerable pressure in the containers.
Never store ammonia near chlorine bleach.
Never mix or use ammonia with bleach.
Ammonia reacts with iodine to create nitrogen triiodide, which is explosive. Ammonia added to hypochlorites liberates dangerous chlorine gas.
184.108.40.206. Benzoyl peroxide
Benzoyl peroxide, when dry, is easily ignited and sensitive to shock. It decomposes spontaneously at temperatures above 50 ºC (122.0 ºF).
220.127.116.11. Carbon disulfide
Carbon disulfide is both very toxic and very flammable; mixed with air, its vapors can be ignited by a steam bath or pipe, a hot plate, or a glowing light bulb.
Catalysts such as palladium or platinum on carbon, platinum oxide, Raney nickel, and other catalysts should be filtered from catalytic hydrogenation reaction mixtures carefully. The recovered catalyst is usually saturated with exposure to air. Particularly in large-scale reactions, the filter cake should not be allowed to become dry.
Another hazard in working with such catalysts is the danger of explosion if additional catalyst is added to a flask in which hydrogen is present.
The funnel containing the catalyst filter cake should be put into a water bath immediately after completion of the filtration.
Chlorine reacts violently with hydrogen or with hydrocarbons when exposed to sunlight. Chlorine gas and chlorine-producing compounds require special handling procedures. Consult the MSDS or call EH&S for more information.
Diazomethane (CH2N2) and closely-related compounds must be treated with extreme caution. They are very toxic; the pure gases and liquids of these compounds explode readily. Solutions are most safely kept in ether.
18.104.22.168. Dimethyl sulfoxide ([CH3]2S0)
Dimethyl sulfoxide ([CH3]2S0) decomposes violently on contact with a large variety of active halogen compounds. Dimethyl sulfoxide has a history of explosions from contact with active metal hydrides. The exact toxicity level of dimethyl sulfoxide is still unknown, but it does penetrate and dissolve substances through the skin membrane.
22.214.171.124. Dry ice
Dry ice must never be kept in a container designed to withstand pressure.
As a practical example, containers with other substances, when stored over dry ice for extended periods, can absorb carbon dioxide (CO2). If one the containers is removed from storage and allowed to come rapidly to room temperature, a dangerous hazard develops. The carbon dioxide builds internal pressure and bursts the container with explosive violence. When removing such a container from storage, loosen the stopper or wrap the container itself in towels and keep behind a shield.
Dry ice is a cryogenic and can produce serious burns on the skin.
Always use appropriate gloves or utensils when handling dry ice. Never use your bare hands!
If a dry ice burn occurs, treat area with generous amounts of room-temperature water and follow procedures as described in Section 3.2.4: Burns and scalds.
126.96.36.199. Drying agents
Drying agents such as Ascariter must not be mixed with phosphorous pentoxide (P2O5) because the mixture may explode if it is warmed with a trace of water.
The cobalt salts used as moisture indicators in some drying agents may be extracted by some organic solvents. Restrict the use of these drying agents to gases.
188.8.131.52. Diethyl diisopropyl (and other ethers)
Never attempt to move containers of ether that appear rusty or corroded.
Diethyl diisopropyl and other ethers are prone to exploding during heating or refluxing because of the presence of peroxides. See Section 5.3.4: Peroxides and peroxide-forming structures.
Ferrous salts or sodium bisulfate can be used to decompose the peroxides, and passage over basic active alumina will remove most of the peroxide material.
However, do not use old containers of ethers. Declare these containers as waste and contact EH&S for removal.
184.108.40.206. Ethylene oxide (C2H4O)
Ethylene oxide (C2H4O) has been known to explode when heated in a closed vessel. When using ethylene oxide under pressure, conduct experiments behind suitable barricades.
220.127.116.11. Halogenated compounds
Halogenated compounds such as chloroform (CHCl3) and carbon tetrachloride (CCl4) must not be dried with sodium, potassium, or other active metal. Violent explosions are usually the result of such attempts. Also, many halogenated compounds are toxic. Use them in a well-ventilated area such as in a fumehood.
18.104.22.168. Hydrogen peroxide (H2O2)
Hydrogen peroxide (H2O2) stronger than 3% undiluted is dangerous; it causes serious burns to the skin. Thirty percent (30%) hydrogen peroxide may decompose violently if contaminated with iron, copper, chromium, and other metals or their salts.
22.214.171.124. Lithium aluminum hydride (LiAlH4)
Lithium aluminum hydride (LiAlH4) must never be used to dry methyl ethers or tetrahydrofuran. Fires resulting from this type of drying are very common. In addition, the products of the reaction of lithium aluminum hydride with carbon dioxide have been reported to be explosive.
Do not use carbon dioxide or bicarbonate extinguishers for lithium aluminum hydride fires. Instead, smother the fire with sand or some other inert substance.
Also, do not use carbon dioxide, carbon tetrachloride, and bicarbonate extinguishers for any alkali metal fires, including lithium aluminum hydride.
Perchlorates such as perchloric acid (HClO4) must be avoided wherever possible. Particularly avoid using perchlorates as drying agents if there is:
Conduct perchloric acid evaporation only in fume hoods designed specifically for that purpose. The hoods must be equipped with plumbing for washdown.
Permanganates are explosive when treated with sulfuric acid. When both compounds are used in an absorption train, an empty trap should be placed between them.
126.96.36.199. Peroxides -- Inorganic
Inorganic peroxides, when mixed with combustible materials such as barium, sodium, and potassium, form explosives that ignite easily.
188.8.131.52. Peroxides -- Organic
Organic peroxides are a class of compounds that have unusual stability problems that make them among the most hazardous substances used in laboratories. As a class, organic peroxides are considered to be powerful explosives. They are sensitive to heat, friction, impact, and light, as well as to strong oxidizing and reducing agents.
All organic peroxides are flammable. See Pages 83 and 84 for more information on organic peroxides. Also see Tables 6 and 7 on Pages 85 and 86.
Suggestions for safe use and storage of ether and other peroxidizable materials:
Never order excess amounts of ether!
Periodically check the condition of ether stocks!
184.108.40.206. Phosphorous (P)
Phosphorous (P) forms explosive mixtures with oxidizing agents. The reaction of phosphorous with aqueous hydroxide causes the combination to produce a gas named phosphine, which may either burst into flame spontaneously or explode in air.
The types of phosphorous are red, white, and yellow. White phosphorous is the most dangerous because it is spontaneously flammable in air. Store white phosphorous under water to prevent this spontaneous reaction.
Other solutions such as oil can be used to keep phosphorous from reacting or becoming explosive. Consult the MSDS for storage information on phosphorous.
220.127.116.11. Phosphorous trichloride (PCl3)
Phosphorous trichloride (PCl3) reacts with water to form phosphoric acid, which decomposes on heating to form phosphine, which may ignite spontaneously or explode. Open containers of phosphorous trichloride with care.
Do not expose and heat samples of phosphorous trichloride without adequate shielding to protect yourself or the person doing the operation.
18.104.22.168. Potassium (K)
Potassium (K) is generally more reactive than sodium, igniting quickly on exposure to humid air. Potassium must be handled under the surface of a hydrocarbon solvent. Mineral oil and toluene are solvents that allow safe handling of potassium.
Destroy scraps of potassium by reaction with h-butyl alcohol.
22.214.171.124. Sodium (Na)
Sodium (Na) is stored safest in a closed container under kerosene, toluene, or other mineral oil. Destroy scraps of sodium by reaction with h-butyl alcohol. Avoid contact with water. Sodium reacts violently with water to form hydrogen and causes sufficient heat for ignition.
126.96.36.199. Sodium azide
Do not pour sodium azide down a copper or lead drain. Lead and copper are part of a family of heavy metal azides that detonate easily and unpredictably.
Sodium azide reacts violently with benzoyl chloride plus potassium hydroxide, bromine, carbon disulfide, chromium oxychloride, copper, lead, nitric acid, dimethylsulfate and dibromomalonitrile.
Sodium azide should not be allowed to come in contact with heavy metals or their salts. Consult EH&S when dealing with sodium azide waste.
188.8.131.52. Sulfuric acid (H2SO4)
Sulfuric acid is one of the most corrosive chemicals known to humans. The chemical is not recommended as a drying agent in dessicators. However, if sulfuric acid must be used, place glass beads in the dessicator to prevent splashing if it is moved.
Always wear protective clothing when handling sulfuric acid.
The use of sulfuric acid in melting point baths should be avoided. Use silicone oil should be used instead.
To dilute sulfuric acid, add the acid slowly to cold water.
184.108.40.206. Trichloroethylene (Cl2CCHCl)
Trichloroethylene (Cl2CCHCl) reacts under a
variety of conditions with potassium or sodium hydroxide to form
dichloroacetylene, which ignites spontaneously in air and detonates readily even
at cold temperatures. The compound itself is highly toxic and suitable
precautions should be taken when it is used as a degreasing solvent.
The temperature measurements given in this manual are in Celsius. Although every effort has been made to include the Fahrenheit equivalent, you can determine the Fahrenheit equivalent yourself through a conversion formula. A formula also exists for converting Fahrenheit into Celsius.
A.1. Celsius to Fahrenheit
To convert Celsius into Fahrenheit, use this
(ºC x [9 ö 5] ) + 32 = ºF.
(- 17.78ºC x [9 ö 5] ) + 32
(- 17.78ºC x 1.8 ) + 32
-32.004 + 32
= - 0.004ºF (0ºF).
A.2. Fahrenheit to Celsius
To convert Fahrenheit into Celsius, use this
(ºF - 32) x (9 ö 5) = ºC.
(32ºF - 32) x (9 ö 5)
0 x 1.8
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