Module One: Rules for Protecting Yourself
Laboratory Safety Starts With You
A laboratory participant should be aware at all times of any hazardous conditions and possibilities that exist within the laboratory/laboratories they work or participate in.
It is vitally important to always keep laboratories clean and uncluttered, walkways unimpeded by trash and storage, free of excessive and/or uncontrolled hazards, and to always maintain free and unobstructed access to safety equipment such as safety showers, eyewashes, and hoods.
The best tool for preventing or limiting unnecessary risk in a laboratory environment is attitude of the laboratory personnel.
Safety starts with
YOU.
Rules for Protecting Yourself
Below are guidelines to follow when working with hazardous chemicals and/or machinery.
- Knowledge of Chemicals
Know what is in the product you are working with. Always consult Material Safety Datasheets (MSDS) before conducting an experiment with chemicals or combinations unknown to you.
- Sufficient is Better
Only get and use the smallest amount of chemical ingredients sufficient to complete the process.
- Maintenance is Critical
Maintain machinery and equipment to prevent leaks or releases.
- Always Ventilate
Use ventilation to reduce amounts of chemicals accumulating in the air. Hood use should be well-understood and properly implemented.
- Personal Protective Equipment
Properly understand and wear necessary personal protective equipment (PPE).
- Constant Awareness
Inform laboratory or departmental supervisors immediately of unusual odors, spills, or releases, or other unsafe conditions.
- Medical Attention Follows Exposure
If you have been exposed to a chemical and feel sick, get medical attention immediately.
- Habitualize Safety
Develop safe laboratory habits.
Module Two: General Chemical Safety
Chemicals are Pervasive
Chemicals exist in our everyday lives, both in the workplace and at home. Acknowledging and understanding chemical safety helps prevent unwarranted and unnecessary risks to life and property.
Chemical Life Cycle
The total chemical life cycle defines the stages of a chemical's purchase, use, and disposal:
- starts from purchasing...
- receiving...
- storage...
- distribution...
- application...
- collection...
- environmental health and safety...
- treatment (of waste and contamination) ...
- disposal
All parts of the cycle need to be handled with appropriate caution.
Chemical Forms in Nature
All chemicals exist in one of four states: solid, liquid, gas or plasma.
Solids
Solids are of a definite shape and volume at room temperature and pressure. Solids may create dust or fumes by cutting, drilling, sanding, grinding or welding that are then released into the air. Risk of inhalation exposure to contaminated air is high.
Liquids
Liquids are characterized by the tendency to flow and be of relative low compressibility at room temperatures and pressures. Liquids may come into contact with the skin and be absorbed into the body. Liquids may also be sprayed and form mists, or evaporate and form vapors, which may then be inhaled.
Gas
Gas is a chemical in the gaseous phase at room temperature, and enters the body by inhalation.
Plasma
A plasma is created when electrons are no longer trapped in orbits around the nucleus. Most of the matter in the universe is found in the plasma state.
Examples of Common Chemicals
Common, everyday chemicals include:
- nail polish remover
- fixative spray
- toner in the office copier
- paints and thinners
- corrosive cleaner
- toxic or flammable solvents
- fungicides
- pesticides
- swimming pool chlorine
Dangers
Many chemicals are flammable, toxic and/or possibly explosive, and may affect the health or life of participants and/or bystanders if not handled properly throughout the chemical life cycle.
Chemical Classification
Chemicals may be classified as
hazardous or
non-hazardous. The Environmental Protection Agency (EPA) has divided hazardous chemicals into several categories useful for understanding compatibility and the need for segregation.
Any chemical containing one or more of the following characteristics is considered a hazardous chemical:
Ignitable Materials
These materials give off heat, smoke, and may disperse toxic pollutants into the air. The flash point generally is below 60 degree C (140 deg F).
Ex: Gasoline, Isopropyl Alcohol.Corrosive Chemicals
These chemicals have a very low or high pH (below 2 or above 12.5), and may cause burns to the skin or body.
Ex: Hydrochloric Acid, Sodium Hydroxide.Reactive Chemicals
When exposed to air, light, or water, these chemicals may detonate, explode or give off poisonous gases. These chemicals include oxidizers, cyanides and sulfides.
Ex: Sodium metal.Toxic Chemicals
The EPA has defined that a toxic chemical is one that possesses a high toxicity by dose/weight. This is determined by dose level as defined by the ratio of potential Lethal Dose 50% (LD50) observed harm calculation (LD50 [orally] < 50 MG/KG). These chemicals may be absorbed through skin, inhalation or ingestion.
Ex: Sodium Cyanide.List waste
Materials regulated by the EPA as a hazardous waste.Listed Constituent
Materials regulated as hazardous based upon component or constituent levels.
General Chemical Handling Precautions
General precautions shall be followed for chemical handling:
- Safety Rules Protect You and Everyone Else
Know safety rules and follow them.- Safety Equipment Locations
Know the locations of MSDS binders, eye wash stations, showers, fire extinguisher(s), and first aid kits.
- MSDS's Provide Important Information
Read the manufacturer's MSDS sheet for all chemicals and warning labels on the packaging prior to starting work.
- Sufficient Use of Chemical
Purchase only the minimal amount of chemical needed and keep only small amounts on the bench for each use.
- Follow Waste Disposal Procedures
Obtain and follow proper waste disposal procedures to discard waste chemicals.
- Prevent Unnecessarily Risky Exposure
Sandals, perforated shoes, and bare feet are prohibited.
- Ingestion, Absorption or Contamination Exposure Prevention
Eating, drinking, smoking, gum chewing, or application of cosmetics in the lab area are prohibited.- Habitualize Safe Work Practices
Apply safe work practices (ex: always add acid or base to water).
- Personal Protective Equipment
Use gloves, goggles, and a face shield as protective equipment when handling chemicals.
- Toxicity is Important
Treat all chemicals as though they were a toxic agent.
- Prevent Chemical Contact with Skin
Skin contact with all chemicals shall be avoided.
- Know Inhalation Hazards of Chemicals
Minimize any inhalation exposure to hazardous chemicals.
- Prevent Ingestion of Harmful Chemicals
Do not smell or taste any chemicals.
Incident Reporting
Report incidents to your supervisor immediately.
Module Three: MSDS Information
Material Safety Datasheets (MSDS)
Material Safety Datasheets (MSDS) are a significant source for product/chemical-specific safety information. OSHA requires chemical manufacturers and importers to produce one MSDS for each hazardous chemical they manufacture or import.
MSDS Definition
- Material Safety Data Sheet (MSDS)
- A compilation of information required under the OSHA Communication Standard on the identity of hazardous chemicals, health, and physical hazards, exposure limits, and precautions.
[source: EPA]
MSDS Sheet Contents
MSDS sheets contain information such as:
- Names of hazardous chemicals
Ex: Acetone, alcohol
- Physical and chemical properties
Ex: Flammable & highly volatile
- Physical hazards of the products
Ex: Burns
- Hazardous ingredients
Ex: Acetone 80%, Alcohol 20%
- Health hazards of the products
Ex: Headaches, eye irritation
- Reactivity of the chemical
Ex: Water reactive
- The main way the chemical enters the body
Ex: Inhalation
- The legal limit allowed in the air
Ex: 750 ppm
- Carcinogenic of the chemical
Ex: Not carcinogenic
- Precautions for safe use of the hazardous chemical
Ex: Use with adequate ventilation
- Exposure control method, including personal protective equipment (PPE)
Ex: Wear respirator, goggles, gloves, etc...
- Emergency and first aid procedures
Ex: Eyes flush with water at least 15 min
- The date the MSDS was prepared
Ex: 2007
- Name, address and phone number of the person responsible for the information in the MSDS
Ex: Mary Jones, 328, Perry Rd, WC,USA, x-394-0001
Location of UNT MSDS Physical Archive
The
RMS web site provides links to several MSDS sources.
Copies of MSDS sheets may also be obtained from:
Risk Management Services
Risk Management Center
Office #117
700 North Texas Blvd, Denton, Texas 76201
(940) 565-4751
Module Four: Storage of Chemicals
Material Data Safety Sheets (MSDS)
Always read MSDS prior to starting any chemical storage. MSDS sheets provide special storage information and incompatibilities.
Storage Groups
Chemicals may be divided in 10 groups for storage. These are:
- flammables
- oxidants
- reducers
- concentrated acids
- concentrated bases
- water reactives
- extreme toxics
- peroxide formers
- pyrophorics
- gas cylinders
Procedures for Hazardous Chemical Storage
Always follow the manufacturer's procedures for toxic, carcinogenic, radioactive, and biological hazardous chemicals storage.
Whenever possible, separate chemicals into the following hazard classes:
- Flammable/combustible
- Flammable solids
- Mineral acids
- Organic acids (liquid)
- Caustics
- Oxidizers
- Perchloric acid
- Water-reactive
- Air-reactive
- Heat-reactive (require refrigeration)
- Unstable (shock-sensitive, explosive)
- Others
- Gases: toxic, flammable, oxidizers and inert
Never store chemicals alphabetically without regard to their hazardous characteristics and reactivity. Once separated into hazard classes, chemicals may be stored alphabetically.
Chemical Compatibility & Proper Storage
Store chemicals in accordance with compatibility. Incompatible chemicals coming into contact can generate extremely violent chemical reaction resulting in catastrophic explosions. Gaseous products may be formed which are dangerously flammable. Vapors can travel for long distance to an ignition source and cause a fire.
Flammable Storage Cabinets
Volumes greater than 1.0 liter of flammable liquids which are stored in glass containers are hazardous and should only be removed from a flammable cabinet when transferring liquid from the container to a smaller container while in a fume hood, and should not be used on the benchtop.
A prudent practice in place of storing greater than 1.0 liters of flammable liquid is to divide larger volumes into several smaller volume containers (less than 1.0 liter each) before storing in a flammable cabinet. Large volume containers of flammable liquids should be returned to flammable cabinet immediately upon completion of transfer of liquid to a smaller container for use (less than 1.0 liter size).
Store flammables in flammable storage cabinets in accordance with National Fire Protection Association (NFPA) codes.
MSDS Incompatibilities
One should always check with the MSDS for chemical incompatibilities before using or storing a chemical. To view an example list of incompatible substances, consult with the
Chemical Hygiene Plan, Appendix C - List of Incompatible Substances.
Flammable Storage Cabinets
Store flammables in flammable storage cabinets in accordance with National Fire Protection Association (NFPA) codes.
Chemical Hazard Diamond
The NFPA 704 system uses a diamond-shaped diagram of symbols and numbers to indicate the degree of hazard associated with a particular chemical or material.
Note: Zero is used to indicate no special hazards, up to four for severe or extreme hazard potential.
- Health hazard (blue section)
Denotes relative hazard to human life- 0 - Normal material
- 1 - Slightly Hazardous
- 2 - Hazardous
- 3 - Extreme Danger
- 4 - Deadly
- Flammability (red section)
Denotes flash point of material- 0 - Will not burn
- 1 - Above 200° F
- 2 - Below 200° F
- 3 - Below 100° F
- 4 - Below 74° F
- Reactivity (yellow section)
Denotes volatility and severity of reactive quality- 0 - Stable
- 1 - Unstable if heated
- 2 - Violent chemical change
- 3 - Shock and heat may detonate
- 4 - May detonate
- Other hazard information (white section)
Denotes symbol used to describe additional hazard warning- Oxidizer (OXY)
- Acid (ACID)
- Alkali (ALK)
- Corrosive (COR)
- Use NO WATER (W)
- Radiation hazard (
)
Storage of Hazardous Chemicals
It is important to follow these basic guidelines when storing each type of hazardous chemical.
Storage of Corrosive Materials
Store corrosive materials near the floor to minimize the danger of falling from shelves. Store in areas that are cool, dry, and well-ventilated, and away from sunlight. Additionally, the storage area should not be subject to rapid changes in humidity or temperature.
Storage of Water-Reactive Chemicals
Water-reactive chemicals should be stored in a cool, dry place. Do not store water-reactive chemicals near or under water sinks. Minimize storage of reactive chemicals.
Storage of Peroxidizable Compounds
Store peroxidizable compounds under a nitrogen atmosphere. Date containers upon receiving and opening. Keep away from heat, light, and ignition sources.
Storage of Oxidizing Chemicals
Store oxidizers in a cool, dry, well-ventilated area, out of direct sunlight. Do not smoke near oxidizers.
Storage of Poisonous Compounds
Treat poisonous compounds with extreme caution. Toxic compounds should be stored according to the nature of the chemical.
Storage of Toxic, Carcinogenic, Radioactive, and Biological Hazards
Follow the manufacturer's procedures for toxic, carcinogenic, radioactive, and biological hazardous chemicals storage.
Gas Cylinder Management
All cylinders should be labeled properly. Compressed gases or liquefied gas cylinders have physical and chemical hazards. Mishandled cylinders may rupture violently, releasing their hazardous contents and/or become dangerous projectiles.
How to protect yourself
Wear appropriate foot protection when engaged in moving or transporting cylinders. Proper personal protective clothing and equipment shall be worn. Always read the MSDS sheet and familiar with the health, flammability, and reactivity hazards for the particular gas.
When receiving gas cylinders
Always check for leaks. Visually inspect the cylinder for damage. Ensure the valve cover and shipping cap are affixed. Check for proper labeling.
How to store gas cylinders
Cylinders should be stored in a dry, well ventilated area at least 20 feet from combustible materials. Gas cylinders should be stored outside of the lab.
Cylinders should be stored in compatible groups: flammables from oxidizers, corrosives from flammables, full cylinders from empties.
Oxygen cylinders must be separated by 20 feet from fuel gas cylinders, such as acetylene, and should be stored upright and secured with a chain or cable. Valves and caps should be completely closed.
How to transport gas cylinders
Secure the cylinders upright. Use a gas cylinder hand truck for transportation.
How to use gas cylinders
Open valves by hand, not with any tool.
Keep cylinders upright and away from heat, sparks, fire, or electrical circuits.
Do not use oil or grease on the oxygen cylinders.
Poison gases
Poison gases like arsine, ethylene oxide, hydrogen cyanide, nitric oxide, and phosphine represent a significant hazard. Fume hoods and other ventilation need to be tested before use and checked frequently during the project involving poison gas.
Emergency procedures should be made available to all personnel, adjacent labs and building representative.
How to maintain gas cylinders
All cylinders should be properly marked to identify the contents. Make sure any empty container is labeled with "EMY", abbreviation for empty.
If cylinders are leaking, remove to outdoors and away from sparks or heat, and empty slowly. Put a warning sign on any cylinder that is leaking and notify the supplier.
Chemical Inventory
It is strongly recommended to perform a full chemical inventory annually. Additionally, best practice recommends keeping sufficient records tracking the most toxic and dangerous chemicals used in a laboratory, including procurement informaton, expected usage, consumption, disposal, and related dates.
Module Five: Chemical Labeling & Posting
Chemical Labeling Regulations
Federal and state regulations mandate that all labels on containers must include the following:
- chemical name
- hazard warning
- name and address of the manufacturer or other responsible party
Note: Prior to storing a chemical, it must be labeled with the date the chemical was received.
Mandatory Chemical Labeling
All secondary containers in the laboratory or workplace shall be labeled according to the following example:
- Name of the chemical: Nitric acid
- Route of entry: Eyes, skin, mucous membrane
- Health hazard: Poison
- Physical hazard: Corrosive
- Target organ affected: Skin and Lungs
Secondary Container's Labeling
It is the worker's responsibility to ensure all secondary containers are labeled with the above information.
Refrigerators Used as Chemical Storage
Refrigerators used for chemical storage must be labeled "For Chemical Storage Only" in a consipicous location on the refrigerator.
Storing food, water or other material meant for ingestion, absorbtion (ex: medical creams) or other bodily uses (ex: makeup) in a refrigerator used for chemical storage is prohibited.
Labeling of Areas Containing Chemical or Hazardous Materials
Caution Placarding
Entrances to shop and laboratory areas where chemicals or hazardous materials are used must be posted with a CAUTION PLACARD sign to indicate the hazard types in the work area.
Emergency Contact Information
Emergency phone numbers must be posted on the entrances of the shop and laboratory.
Proper Placard and Contact Information Responsibility
The manager or supervisor of the shop or laboratory is responsible to ensure work areas and entrances are appropriately posted with required information.
Module Six: Chemical Spill Procedures
Spill Prevention
Preventing spills is the most effective way to protect life and property. Always invest effort in effective planning, use of chemicals in experiments and work practices, transportation and storage of chemicals, and proper housekeeping to minimum the likelihood of a spill occurring.
Identifying & Reporting Chemical Spills
Proper handling of spills is essential to effective laboratory safety practices. Spills may happen at any time, to anyone. Preparing for the eventuality of spills is crucial to knowing how to respond effectively and critically when they do occur.
Responding to Spills, By Size
The size of a spill indicates the level of response to spill incident. Small spills (less than 100 ml) may be handled by the laboratory personnel, whereas large spills should be handled by the university's Risk Management Services or a chemical response team after alerting 911 in case of emergency.
Chemical spills should be identified as small and large spills when reporting the spill.
Handling Large Spills
For large spills that do not threaten a person's safety, always contact Risk Management Services Environmental Services office at 940-565-4751 for assistance (call 817-403-9833 if after hours).
Note: For
emergencies, call 911, 24 hours a day.
Handling Small Spills
For small chemical spills (< 100 ml):
- Acid spill
- Use sodium bicarbonate to neutralize the acid.
- Mix thoroughly until fizzing and evolution of gas ceases. It may be necessary to add water to the mixture to complete the reaction.
- Check pH with indicator paper to make sure acid has been neutralized.
- Transfer the mixture to a plastic bag and label acid waste.
- Request a pick up from the RMS waste website.
- Add water in large quantities to neutralize acid spill, only if the spill is within a few milliliters.
- Caustic spill
- Apply acid to neutralize the base.
- Mix thoroughly until fizzing and evolution of gas ceases.
- Check pH with indicator paper to make sure base has been neutralized.
- Transfer the mixture to a plastic bag and label caustic waste.
- Request a pick up through the RMS waste website.
- Solvent spill
- Apply activated charcoal to the perimeter of the spill.
- Mix thoroughly until material is dry and no evidence of liquid solvent remains.
- Transfer absorbed solvent to a compatible plastic bag.
- Notify RMS for disposal.
- Mercury spill
- Dampen the mercury sponge with water, then wipe the contaminated area.
- Place the contaminated sponge in its plastic bag, tie shut and attach a mercury waste label.
- Request a pick up through the RMS waste web site.
- Biohazard spill
- Human body fluid and blood should be treated as infectious hazard.
- Call RMS at 940-565-4751 immediately for further assistance.
Handling Minor Spills
Minor spills should be cleaned up immediately by the worker or laboratory personnel, using the procedures described above.
Handling Flammable or Health/Life Threatening Spills
Do not try to clean the spill if it is flammable or immediately dangerous to health or life. Alert others and evacuate the immediate area, and contact Risk Management Services at 940-565-4219 for assistance.
Chemicals on the skin
Immediately flush with cold water for no less than 15 minutes and wash with a mild detergent, like soap and water. If a reaction is noted, seek medical attention immediately.
Chemicals on the clothes
In case hazardous chemicals spill onto clothing:
- Be careful not to spread undiluted the chemical directly to the skin, if possible.
- Quickly remove all the contaminated clothing while using the safety shower.
- Flood the affected body with cold water for at least 15 minutes.
- If any pain persists, get medical attention as soon as possible.
Module Seven: Personal Protective Equipment
Personal protective equipment provides a barrier between the individual employee and a potential hazard.
Eye Protection
Eye protection should always be considered before conducting any work or experiment. Additionally, always know the location of the nearest eyewash station in a laboratory before removing chemicals froms storage and beginning an experiment.
Guidelines for when to put on protective eyewear:
- Safety goggles are necessary when there is a potential chemicals to splash and flying objects in the work or laboratory area.
- Appropriate eye protection should be worn when using or creating:
- caustics
- corrosives
- irritants
- flammable materials
- cryogenics
- explosives
- biohazards
- radioactive materials
- Eye protection should also be worn when performing these machine shop functions:
- welding
- sanding
- drilling
- grinding
- sawing
Protective Clothing
Lab coats are designed to protect clothing and skin from chemicals that may spill or splash.
Different types of lab coats are available that offer different types of protection:
- Cotton - Protects against flying objects, sharp or rough edges.
- Wool - Protects against splashes of molten materials, small quantities of acid, and small flames.
- Synthetic fiber - Protects against sparks and infrared or uv radiation.
- Aluminized and reflective clothing - Protects against radiant heat.
Aprons provide an alternative to the lab coat. An apron should be worn over garments that adequately cover the arms and body.
Hand Protection
Gloves should be worn on the basis of the material being handled and the particular hazard involved, as they are a shield between hands and hazardous materials.
Guidelines for selecting effective hand protection:
- Selecting an Appropriate Glove
- The type of glove must be selected to fit the nature of the work.
- PVC protects against mild corrosives and irritants.
- Latex provides light protection against irritants and limited protection against infectious agents.
- Natural Rubber protects against mild corrosive materials and electric shock.
- Neoprene gloves are for working with solvents, oils, or mild corrosive material.
- When working with extremely corrosive material, wear thick gloves.
- Follow Precautions
- Take extra precaution in checking for holes, punctures, and tears in the gloves before using.
- Wash hands as soon as possible after removing protective gloves.
Foot Protection
Foot protection prevents injury from corrosive chemicals, heavy objects, electrical shock and wet floors. Shoes that completely cover the foot and ankle are recommended.
Note: Never wear footwear that offers little or no protection on the top, sides, bottom and ankle portions of the foot. This includes:
- sandles, clogs, or flip-flops
- women's flats or high-heels
- footwear with holes that are uncovered
- ankle-less footwear
- slipons or mesh-covered footwear
Guidelines for selecting effective protective footwear:
- Select sturdy shoes that cover the foot for the work place or laboratory.
- Footwear should at all times completely cover the foot and ankle.
- Safety shoes, rubber boots or plastic shoe covers protect against specific types of chemical contamination.
Hearing Protection
Ear protection should be worn where the noise level is above 85 decibels (dBA).
- Areas where excessive noise is present at any time should be posted with signs indicating ear protection is required.
- Ear plugs or ear muffs should provide basic protection to seal ears against noise.
- Ear protection should be rated adequately to lower dBA levels from the expected peak exposure to a non-destructive level.
Respiratory Protection
Acids, bases and toxic chemicals may create vapor and noxious fumes, and are considered acute respiratory hazards. These materials may enter the body through the skin and the lungs through inhalation. Respiratory protection is required for working with these chemicals.
Air-purifying respirator equipment should match the specific type of cartridge with the anticipated chemical protective usage. Contact Risk Management Services (940-565-4751) for assistance in selecting the correct respiratory protection.
Module Eight: Waste Disposal
Appropriate and adequate disposal of waste is critical in preventing unecessary risk to the environment, as well as lowering the likelihood of unsafe conditions. The last element of the total chemical life is waste.
Chemical Recovery & Re-Use
Chemicals may be recovered, recycled, or re-used safely at the end-of-life-cycle stage. Careful, organized housekeeping operations reduce waste and the likelihood of an an accidental spill or contamination event.
Creative thinking can help you to redesign procedures to use less chemicals, create less waste, prevent fugitive emissions, and minimize unnecessary discharges to the sanitary sewer.
Identifying Hazardous Chemical Waste
Properly arranging for appropriate disposal of chemical waste labeled hazardous is very important.
Hazardous Material Pickup Requests
UNT Risk Management Services maintains an online form for
requesting hazardous material pickups on-campus. Use this form for requesting pickups of any materials deemed hazardous.
Biological Waste Disposal
Biological waste (material, sharps and glassware) is handled by the
Biology Department (940-565-2011). Contact the Biology Department for biological waste disposal procedures.
Hazardous Characteristics
Chemical waste is hazardous if it exhibits the following characteristics:
- Ignitability – EPA waste code D001 -- Ignitable waste gives off heat, smoke, and soot, and may disperse toxic pollutants and by-products into the air. Additionally, liquid wastes such as solvents may catch on fire.
- Corrosivity – EPA waste code D002 – Corrosive wastes include acids and bases that may cause injury to the skin or body.
- Reactivity – EPA waste code D003 – Reactive chemicals can react violently or give off poisonous gases when exposed to light, air, water or other materials.
- Toxicity – EPA waste code D004 – D042 – Toxic wastes are harmful or fatal when ingested or absorbed. If your waste contains pesticides, organic constituents and metals, it is a hazardous waste.
Any waste may be disposed as regular trash if it does not exhibit the above characteristics.
Regulation of Hazardous Chemical Waste
Disposal of hazardous chemicals is strictly regulated under the Resource Conservation and Recovery Act (RCRA), the Texas Hazardous Waste Management Regulations, and the Environmental Protection Agency (EPA) regulations CFR 40, parts 100-399.
Nanoparticles Safety
Nanochemistry is a new discipline with structures that have unique properties. These are assemblies of atoms or molecules on a scale of the building blocks. They are ultrafine particles measuring in between 1-100 nanometers (nm). The use of nanoscale structures, devices and systems that may have utility for chemicals that require nanoscale applications. The advantage of nanomaterials is that they provide so much more surface area than the same amount of larger-grained materials. They can create products which are much more durable, effective, wear-free and other possibilities yet to be discovered.
Nanoparticles act like a gas and pass through skin and lung tissue to penetrate cell membranes. Once inside the cell, they might become toxic or disrupt normal cell chemistry. Threadlike nanotubes are structurally similar to asbestos fibers, which can cause lung problems when inhaled in large amounts over long periods. It is strongly recommended that nanoparticle stocks when dry should be handled inside an appropriate glove box. Workers should wear protective equipment, including safety goggles, lab coats, and gloves if handling or transporting materials outside of a glovebox. Nanoparticle solutions may be handled on the lab bench once placed in solution. Workers should wear protective equipment, including safety goggles, lab coats, and gloves. Transport of nano-materials should employ a secondary containment device. Limit access in areas where experiments are being carried out. Only trained personnel may be permitted to work in these areas. Nanoparticle waste must be contained and labeled for chemical content.
Use the Risk Management Website (http://rms.unt.edu) to "Request Haz Pickup". Contact the HazMat Officer at 940-369-8084 with any questions about a pick up. Prohibit of eating and drinking in laboratories. Equipment used for handling of nanoparticles must be evaluated for safety concerns. Regular cleaning of benchtops, floors and other surfaces with bleach or other applicable disinfectant.
Report any incident to your supervisor.
Commonly Use Hazardous Chemicals
A hazardous chemical is defined as a flammable, combustible, explosive, or reactive substance. These substances cause an acute or chronic irreversible health effect when overexposure occurs.
Organic Peroxides
Many organic peroxides are low-power explosives; however, some are very powerful and are extremely sensitive to shock, sparks or other forms of ignition. When handling peroxides, personnel should avoid any heat, friction, impact, light, strong oxidizing and reducing agents.
All organic peroxides are extremely flammable and fires involving bulk quantities should be approached with extreme caution.
Additionally, peroxides have a specific degradation half-life. Be sure the container is labeled with the opened and exposed date. Limit the shelf life of these peroxides to six months. Ask your lab safety officer for a peroxide shelf life form to fill out your new chemical's opened and expired date.
Compounds that form peroxides are aldehydes, ethers (especially cyclic ethers and ethers containing primary and secondary alcohol groups), and compounds containing benzylic hydrogen atoms. A good example is cumene (isopropyl benzene), compounds containing the allylic structure (CH2=CHCH2R), e.g., olefins, cyclic ketones, vinyl and vinylidene compounds, vinyl acetate and vinylidene chloride.
Chemicals that can form peroxides are listed below but not inclusively:
- cyclohexene
- cyclooctene
- decalin
- p-dioxane
- ethyl ether
- isopropyl ether
- tetrahydrofuran
- tetralin
Benzene
Benzene is considered an OSHA Category I Carcinogen. An authorization for using benzene solution must be approved by your supervisor.
Chronic exposure to benzene can cause leukemia. Avoid benzene having direct contact with skin or mucous membrane. Benzene has a potential for skin absorption and causes skin cracking and dryness.
Substitute less toxic reagent like toluene for benzene. The current OSHA permissible exposure limit is 1.0 ppm.
Carbon Tetrachloride
Carbon tetrachloride may also be absorbed through the skin. Less severe exposure can lead to kidney and liver damage. High concentrations in the air can rapidly cause death.
Whenever possible, substitute with dichloromethane. The current OSHA threshold limit value for carbon tetrachloride is 5.0 ppm.
Formaldehyde
Formaldehyde is a known human carcinogen, and is also a severe eye irritant. Skin sensitization can result from repeated exposure.
Formaldehyde is a colorless, pungent, irritant gas that is frequently marketed as 37-56% aqueous solutions, commonly called formalin.
Experiments involving formaldehyde should be performed in a fume hood. Use neoprene, polyvinyl chloride gloves, splash-proof goggles to avoid any possibility of splashing formaldehyde in the eyes. The current OSHA threshold limit for formaldehyde is 1.0 ppm.
Perchloric Acid
Perchloric acid is a clear liquid with no odor, and is a very reactive chemical. At room temperatures, 72% perchloric acid solution reacts as a strong non-oxidizing acid.
Fire or explosion can occur if it contacts with combustible materials at elevated temperatures. Carry out experiments in a "wash down" hood specially designed for perchloric acid.
ALWAYS
- Use Safer Replacement - Substitute a hazardous material with a less hazardous one.
- Minimization - Reduce risk by using only the least quantity of haazardous chemical needed.
- Isolation - Engineering controls like glove box and blast shield must be in position.
