3 Hazard Identification Certain regulations require that the receivers and occasionally the shippers, must be identify hazardous chemicals before transporting them. In order to do this, teachers must be aware of and understand the various common warning and identification systems. There is a language to these systems that teacher must learn.
4 Hazard Identification Each of these systems has its place and each has limitations. Some will affect the teacher’s job and others might be incidental. In some cases, such as the NFPA 704 M system, the process has been adopted for purposes other than intended by its creators. It is essential that we understand each.
5 Identifying Hazardous Chemicals What do we mean by Identification? It is determining specifically what chemical or what chemical class is involved in a particular shipment or container. We do this in the lab continuously from the time we receive the chemical until it leaves our facility.
6 Identifying Hazardous Chemicals Identification might mean that we see and understand a label on the container or that we read the warning label on the bottle or it might mean we know how to ascertain important information from a secondary container label. In all these cases there is information that we need.
7 Identifying Hazardous Chemicals Hazardous chemicals are classified by the department of Department of Transportation in CFR 49. These hazard classes are common in almost all systems in one respect or another. Here are the classes. Note that some classes have Divisions for further clarity.ExplosivesGasesFlammableNonflammablePoisonous Inhalation HazardCorrosiveFlammable LiquidsOxidizersOxygenOrganic PeroxidesPoisonsRadioactive MaterialsCorrosivesMiscellaneousOther Regulated Materials
8 Identifying Hazardous Chemicals PLACARDS AND LABELSPlacards are found on transportation vehicles although one may occasionally see them on containers if the container is considered a Bulk Container. Placards are roughly 11” by 11” and are required on all four sides of a vehicle carrying a certain amount of the regulated chemical.Labels are very similar and are placed directly upon the shipping container. This might be a box, bottle, carboys, or cylinder. These labels are 4” by 4”.
9 Identifying Hazardous Chemicals PLACARDS AND LABELSDOT requires that all labels and placards use the same format. This format provides several indicators as to the class and division of the chemical in the container but note it does not provide chemical specific information.Placards have aPictographWarning Word(s)DOT Class NumberTo see allclass labels
10 Identifying Hazardous Chemicals PLACARDS AND LABELS1994DOT regulations require certain containers andvehicles be signed with placards that containa 4 digit number.This number is called the United Nations CommonNumber and is a tool used to identify the chemical or chemical group. These numbers are also used on containers of hazardous waste although they are not usually required unless in shipment. You can look reference these UN Numbers in the Emergency Response Guidebook.
11 Identifying Hazardous Chemicals One identification system has been around for many years. That is the NFPA 704M System for Fixed Facilities. The National Fire Protection Association created this system to mark buildings containing chemicals in which firefighters might be forced to fight fire. The system never really caught on nationally but has been given a second life in the marking of portable containers and hazardous waste containers. It is now fairly common on labels for chemicals.
12 Identifying Hazardous Chemicals Each segment of the label using the NFPA 704M System denotes a particular hazard of the product in the container. The colors and the numbers are significant.The number range from 0 to 4 with each category having its own verbal equivalent.Health4 – Can cause death or major injury despite medical treatment.3 – Can cause serious injury despite medical treatment.2 – Can cause injury. Requires prompt treatment.1 – Can cause irritation if not treated.0 – No hazard.
13 Identifying Hazardous Chemicals FireNFPA 704M System for Fixed FacilitiesFlammability hazard4 - Very flammable gases or very volatile flammable liquids.3 - Can be ignited at all normal temperatures.2 - Ignites if moderately heated.1 – Ignites after considerable preheating.0 – No hazard.
14 Identifying Hazardous Chemicals 4 – Readily detonates or explodes.3 – Can detonate or explode but requires strong initiating force or heating under confinement.2 – Normally unstable but will not detonate.1 – Normally stable. Unstable at high temperature and pressure. Reacts with water.0 – Normally stable. Not reactive with water.Color CodingNFPA 704M System for Fixed FacilitiesReactivity
15 Identifying Hazardous Chemicals Color CodingNFPA 704M System for Fixed FacilitiesOTHER (white) indicates special warnings.ACID – acidALK – alkaliCOR – corrosive P – subject to polymerization when mixed with waterOXY – oxidizing chemicalsW - do not use water - Radiation Symbol (trefoil)SpecialInformation
16 Identifying Hazardous Chemicals Portable containers of chemicals used in the lab and Hazardous Waste must be identified according to the hazards they represent. The NFPA 704M diamond may accompany a variety of hazardous waste stickers depending upon the company providing the label. There is no regulation that says specifically how these labels must appear. They may use the diamond or may simply use the same colors as the 704 system. They may also provide information on the safe handling of the material.
17 Identifying Hazardous Chemicals A Safety GlassesB Safety Glasses and GlovesC Safety Glasses, Gloves and an ApronD Face Shield, Gloves and an ApronE Safety Glasses, Gloves and a Dust RespiratorF Safety Glasses, Gloves, Apron and a Dust Respirator G Safety Glasses, a Vapor RespiratorH Splash Goggles, Gloves, Apron and a Vapor RespiratorI Safety Glasses, Gloves and a Dust/vapor RespiratorJ Splash Goggles, Gloves, Apron and a Dust/vapor RespiratorK Airline Hood or Mask, Gloves, Full Suit and BootsL - Z Custom PPE Specified by Employer
18 Identifying Hazardous Chemicals A common misconception is that a gas cylinder’s contents can be identified by the color of the cylinder. Where some gas chemical companies may chose to use the color coding system recommended by the American National Standards Institute, it is not mandatory in any sense.
19 Identifying Hazardous Chemicals The following colors may be used by the medical gas industry in the United States to aid in identifying a medical gas.Carbon Dioxide - gray;Helium - brown;Medical Air - yellow;Nitrogen - black;Nitrous Oxide - blue;Oxygen - greenBlends of medical gases use a combination of the corresponding color for each component gas. For example, oxygen and carbon dioxide would be green and gray.
20 Labeling Requirements Primary ContainersAs the teacher receives each new chemical, care should be taken to protect the label on the container. The label has very valuable information as to formula and mixture. Each chemical should be accompanied by an MSDS. Make certain these are filed in the administration office as well as in the classroom lab.
21 Understanding and Using Material Safety Data Sheets (MSDS)
22 MATERIAL SAFETY DATA SHEETS (MSDS) The MSDS is used by chemical manufacturers and vendors to convey hazard information to users.MSDS’s must be obtained when a chemical is purchased.A chemical inventory list, and MSDS, for each chemical are required to be maintained by all OSD facilities.
23 Material Safety Data Sheets (cont’d) MSDSs have no prescribed format. They look very different depending upon the manufacturer’s preference. MSDSs are not ordinarily prepared by chemists or in some cases not even by specialists. OSHA has no criteria for those assigned to prepare them. It is therefore possible that data on the MSDS is in error. Any serious attempt to discover the properties of a chemical should utilize multiple resources.One MSDS may apply to multiple complex mixtures having similar contents and hazards.For information regarding the preparation of MSDSs, see ANSI Z400.1, Hazardous Industrial Chemicals – Material Safety Data Sheets – Preparation.
24 READING THE MSDS Information on the MSDS is organized in 8 sections as follows: Identity The chemical name, trade name and manufacturers name, address and emergency phone number can be found here.Hazardous Ingredients Hazardous ingredients are identified here.Physical and Chemical Characteristics, Boiling/Melting point, vapor pressure and density, water solubility, and appearance/odor can be found here.Continued on next slide...
25 READING THE MSDS 8 Sections Continued Fire Data Flash point, flammable limits, extinguishing media, unusual fire/explosion hazards, and any special fire fighting equipment are listed here.Health Data Routes of entry (inhalation, ingestion, etc…), effects from short and long term exposure, emergency and first aid procedures fall in this section.Reactivity Data Stability, incompatible materials, hazardous decomposition are among the topics in this area.Continued on next slide...
26 READING THE MSDS 8 Sections Continued Spill or Leak Procedures You will find clean-up procedures, waste disposal, and precautions needed when handling/storing materials here.Spill Precaution Information Any personal protective equipment (PPE), ventilation, and work/hygiene practices are noted here.More on MSDS
27 DEFINITIONSFlammable: A substance having a flash point below 100 (140 for DOT and EPA) degrees Fahrenheit - easily ignited and quick burning.Toxic: A substance which has the capacity, through chemical reaction or mixture, to produce injury or harm to the body by entry through absorption, ingestion, inhalation, or injection.Caustic: A substance with the capability of burning, destroying or eating away organic tissue by chemical reaction - Corrosive.
29 05/21/99Toxic Materials Assessing the risks due to the toxic effects of chemicalsIn order to understand what an MSDS is telling us we must understand a little about the hazards of chemicals so we will look at the following areas of concern:Route of exposureAcute ToxicantsCorrosive Substances, Irritants and AllergensCarcinogensTeratogens and Mutagens12
30 Routes of ExposureChemical exposure essentially means that the chemical has found a route into our body. Exposure occurs through one or more to four routes.IngestionInhalationSkin contactInjection
31 Routes of Exposure Ingestion The users of chemicals seldom ingest chemicals on purpose. The most common way in which chemicals are ingested is when the chemical user fails to wash their hands after handling the chemicals. Subsequent eating, drinking or smoking may introduce chemicals into the body. Hand washing is an essential part of the laboratory teacher’s job and a habit that should be instilled in students as well.
32 Routes of Exposure Inhalation Inhaling chemicals is particularly dangerous since the respiratory system provides direct and rapid access to the blood stream. In general, one should not smell chemicals intentionally. This is a poor method of identifying the chemical since odor is not a reliable means of determining concentration. One can be over exposed prior to odor being detected.
33 Routes of Exposure Skin Contact It is not uncommon to discover a belief that skin is water proof. Quite the contrary, skin readily absorbs many liquids and gases from the air or on its surface. Again, hand washing is a critical tool for limiting exposure. Gloves are also important since the best way to decontaminate the skin is not to contaminate it in the first place.
34 Routes of Exposure Injection Injection can occur in several ways. One is the injection of a chemical using a syringe but this is rare. Much more common is injection while cleaning up after a spill where glassware has shattered. It may be advisable to either double glove with a cut protection glove and a chemically resistant glove during a cleanup of this type or to only pick the glass up with tongs.
35 What is Toxicity?Toxicity is the degree to which a substance can harm humans, animals or other life forms. Toxicologists and physicians differ on what a toxin is. Physicians identify a toxin as a substance not intended for human consumption that is harmful.Physicians call the harm caused by those substances that are intended for human consumption an overdose.There are many common substances that can poison:WaterSaltAlcohol
36 What is Toxicity?Toxicologists call anything that enters the biological unit (body) from the outside a xenobiotic. The key to whether or not a xenobiotic is of concern for the biological unit is a matter of dosage.Toxicology is based upon the concept that any substance in the correct amount is bad for you.Signs of Arsenic Poisoning
37 Hazmat ToxicologyDose is the amount of a xenobiotic taken into the body. The word dose is meaningless without a reference to time. It is measured in units of weight and volume and frequently considers the weight of the biological unit in kg.Concentration is a measure of the degree of exposure. How much of the material (usually in the air) one was exposed to over a period of time.
38 Hazmat ToxicologyExposures are categorized based upon how long the exposure occurred and how much of the material was involved.Types of ExposureAcute - A lot of the poison in a short period of time.Chronic - A little of the poison over a long period of time.Sub acute - many acute exposures over a long period of time.
39 Toxicity of commonly used chemicals 05/21/99Toxicity of commonly used chemicalsChemicalOralLD50(rat, mg/kg)SkinLC(rabbit)InhalationLD(rat, ppm 1/ hr)Acetone5800no datahrAcetonitrile2460982.57551 8hrmoderately toxic by skin absorptionAcrylamide124400NAmoderately toxic by ingestion, skinabsorption. OSHA CarcinogenMethanol562815800hrMethyl Isocyanate51.5hr220acutely toxic by skin abs, ingestionTetrodotoxin3.8X10-3mg/kgone of the most toxic substancesknown to man16
40 Hazmat ToxicologyLikewise the effects of the exposure are categorized depending upon their impact on the body and the period of time that expires before the effects are realized.Internal Effects of ExposureAcute effects - those that are seen immediately.Chronic effects - those that are not seen for months or years
41 Hazmat Toxicology Effects of Exposure Mutagens are chemicals that alter the DNA of the person exposed. This causes a change in some element of subsequent generations of that person. The exposed person may or may not have effects while their children or grand children will.
42 Toxic Materials A Short List of Teratogens 05/21/99Toxic Materials A Short List of TeratogensAmong the types of effects that chemicals might have on our bodies that of a teratogen is certainly attention getting.Teratogens are substances which cause birth defects in the developing embryo or fetus. No other generation is affected.Acetylsalicylic acidBenzeneCaffeineCamphorated oilCannabisDiazepamDilantinFolic acidGlycol ethers12
43 Hazmat Toxicology Effects of Exposure Irritants ordinarily do not cause serious harm. Typically they cause reactions such as tearing, burning, sneezing or some other irritating result. It is important to realize that every body is different and because one person reacts by coughing that does not mean another may not have an allergic reaction that leads to death. Complications such as asthma or bronchitis may also make chemical exposure more serious.
44 Hazmat Toxicology Effects of Exposure Asphyxiates cause illness and perhaps death by limiting the ability of the body to process oxygen. Perhaps the most common is carbon monoxide. CO has about 300 times the affinity for hemoglobin in the blood as does oxygen. Once CO gets into the blood the only way to get it out is for the blood cell to die.
45 Hazmat Toxicology Effects of Exposure Carcinogens are those chemicals that cause, it may be more correct to say activate, cancer. A known human carcinogen means there is sufficient evidence of a cause and effect relationship between exposure to the material and cancer in humans. Such determination requires evidence from epidemiologic (demographic and statistical), clinical, and/or tissue/cell studies involving humans who were exposed to the substance in question. See NIOSH carcinogen list.
46 Examples of materials with a High Level of Acute Toxicity 05/21/99Examples of materials with a High Level of Acute ToxicitySome chemicals have acute toxic effects. In other words they cause immediate negative health effects.Toxicity is always a matter of dosage against time. When the danger of a chemical is discussed in must be in those terms.AcroleinDiazomethaneHydrogen cyanideHydrogen fluorideBiological toxins; Tetrodotoxin, snake venomsOsmium tetroxideBeta-mercaptoethanol15
47 EVALUATING THE RISK OF CHEMICAL EXPOSURES One way that we can determine the danger of a chemical is to examine the THRESHOLD LIMIT VALUES (TLV’s) of the chemical as assigned by the American Conference of Governmental Industrial Hygienists. These are a non-mandatory professional guideline for chemical exposures.The TLVs are the airborne concentration limits of substances under which nearly all workers may be repeatedly exposed without adverse effect. TLVs are non-political, conservative limits to chemical exposure and are given as amount of chemical against a time or time weighted average.
48 CONTROLLING THE RISK OF CHEMICAL EXPOSURES Permissible Exposure Limits (PELs) are the Federally regulated exposure limits as pronounced by OSHA and are described in CFR These limits are agreed upon after public hearings are conducted and industry plays a role in their establishment. TLVs are usually more conservative than PELs however PELs represent the law of the land.PELs are slow to change and are not periodically reviewed while TLVs are reviewed annually and changed based on any new information.
49 CONTROLLING THE RISK OF CHEMICAL EXPOSURES Both PELs and TLV/TWA are based upon the amount of a chemical to which an employee can be exposed without serious health effects. PELs and TLV/TWAs are based upon an 8 hour work day and a 40 hour work week.There are also Short Term Exposure Levels (STEL) This is the amount of a chemical that an employee can be exposed for 15 minutes no more than four times per day without suffering any serious health effects.
50 CONTROLLING THE RISK OF CHEMICAL EXPOSURES The OSHA also publishes Ceiling Limits. Ceiling limits are the amount of the chemical to which an employee should never be exposed. ACGIH publishes Immediately Dangerous to Life or Health (IDLH) exposure limits which is the amount of the chemical exposure which would cause irreversible harm after just 15 minutes.One might find another warning with certain chemicals and that is a Skin Notation. This means that the chemical has been proven to cause negative health effects based upon skin exposure alone.
51 CONTROLLING THE RISK OF CHEMICAL EXPOSURES A common notation associated with chemicals is LD50 orLC50. This is the amount of the chemical that caused death in fifty percent of the laboratory animals exposed. Whereas this number has some shock value, it is not particularly valuable for school laboratory use. Most significantly, a lot on negative health effects could be realized before one’s exposure got anywhere near the LC50. These numbers should not be depended upon for exposure control purposes.
53 FlammabilityWhen we say a chemical is flammable we mean something very specific. Neither paper nor cloth is flammable. In fact oil, grease and paraffin are not flammable either. Because a substance will burn does not mean it is flammable as will be seen.Everything burns, even water. If water is heated rapidly even and hot enough it breaks down into Oxygen and Hydrogen. This is the essence of the perfect fire.
54 05/21/99Flammable LiquidsFlash Point - The lowest temperature at which a liquid has sufficient vapor pressure to form an ignitable mixture with air near the surface of the liquid. In general the lower the flash point the more dangerous the liquid.OSHA and the EPA consider any liquid with a flashpoint of 140 degrees F. or below to be Flammable. With these materials the concern should be other materials that may react with the flammables, ventilation to eliminate the build up of explosive vapors, and segregation from ignition sources such as open flame or electrical sources.18
55 05/21/99Flammability HazardsBelow are some examples of chemicals and there flashpoints.17
56 Flammable GasesWhen we say a gas is flammable we mean is ignites readily in certain concentrations.A flammable gas is any material which is a gas at 68 oF or less and 14.7 psi of pressure which…Is ignitable at 14.7 psi when in a mixture of 13 percent or less by volume with air; orHas a flammable range at 14.7 psi with air of at least 12 percent regardless of the lower limit.
57 Flammable Limits LFL UFL 0% Flammable Range Percentage in AirPercentage in Air1234561617180%Flammable RangeSlide: This slide shows elements of an MSDS.Notes: Refer to Condensed Chemical Dictionary for definitions.Points:WHY 10% OF LEL? (Ask class to point out the level that should begin to cause you concern upon entry.)Instruments are calibrated with a known product (methane) which may react differently than chemical being measured.Environment (temperature, humidity, etc) may affect accuracy of instrument.People make mistakes.LFLUFLIf the the Lower Flammable Limit is less than 13% the gas is flammable.
58 Flammable Limits LFL UFL Flammable Range 0% 100% Lowest percentage in air that is ignitableHighest percentage in air that is ignitableFlammable Range0%100%Slide: This slide shows elements of an MSDS.Notes: Refer to Condensed Chemical Dictionary for definitions.Points:WHY 10% OF LEL? (Ask class to point out the level that should begin to cause you concern upon entry.)Instruments are calibrated with a known product (methane) which may react differently than chemical being measured.Environment (temperature, humidity, etc) may affect accuracy of instrument.People make mistakes.LFLUFLIf there are 12 or more than percentage points between the lower and upper flammable limits, the gas is flammable.
59 Magnesium burning on a tile floor Flammable SolidA flammable solid is defined by the U.S. Department of Transportation (DOT) quite extensively as desensitized explosives such as those wetted with sufficient water, alcohol, or plasticizer used to suppress explosive properties. Self-reactive materials that are thermally unstable and that can undergo a strongly exothermic (heat-evolving) decomposition even without the participation of oxygen (air) are also considered flammable solids.Magnesium burning on a tile floorSlide: This slide shows elements of an MSDS and continues the discussion of explosive limits.Notes: Refer to Condensed Chemical Dictionary for definitions.Points:WHY 10% OF LEL? Because the concentration usually gets higher as you move towards the center of a vapor or gas cloud. If your meter says the concentration is getting higher then that usually means you are moving closer to the area of higher concentrations.
60 Flammable SolidMostly readily combustible solids fall into this category such as solids which may cause a fire through friction, such as matches of road fusees. Some materials are pyrophoric (literally, "fire-loving") materials, which can ignite with no external ignition source within five minutes after coming in contact with air. Others are self-heating materials, those that exhibit spontaneous ignition or heat themselves to a temperature of 200 deg.C (392 deg.F) during a 24-hour test period. (This behavior is called spontaneous combustion). Finally there are dangerous when wet materials, those that react with water to become spontaneously flammable or to give off flammable gas or toxic gas at a rate greater than 1 liter per kilogram of the material, per hour.Slide: This slide shows elements of an MSDS and continues the discussion of explosive limits.Notes: Refer to Condensed Chemical Dictionary for definitions.Points:WHY 10% OF LEL? Because the concentration usually gets higher as you move towards the center of a vapor or gas cloud. If your meter says the concentration is getting higher then that usually means you are moving closer to the area of higher concentrations.
61 05/21/99Flammability HazardsAlso of concern is the chemical’s ignition temperature. This is the minimum temperature at which the material will ignite without the aid of an ignition source. Ray Bradbury tells us that the ignition temperature of paper for example is 451 degrees F. Materials which are being heating may ignite under a variety of circumstances but certainly if the ignition temperature is reached. The MSDS will provide the ignition temperature.Examples of IT17
62 Caustic Chemical Hazards 05/21/99Caustic Chemical HazardsAccidental contact with corrosives is one of the potential dangers in a laboratory or industrial setting. Universally, the term corrosives refer to substances without any toxicological activity which produce severe tissue destruction. Most common are the strong acids or alkalis, but any strong oxidizing or reducing agent such as potassium permanganate and diborane respectively may also be included.Photo of Acid BurnPhoto of Alkali Burn19
63 Caustic Chemical Hazards 05/21/99Caustic Chemical HazardsMost corrosives produce significant injuries through direct chemical reaction on living tissues rather than through heat damage. In most cases, the degree of tissue destruction depends on the concentration of the toxic agent and the duration of the contact.When the skin is exposed to a corrosive, its keratinous covering is destroyed and its underlying dermal tissues are exposed to continuous necrotizing action. The absorption of some corrosives through the skin may cause systemic toxicity. For example; picric acid and phosphorus burns may be followed by kidney damage.19
64 Caustic Chemical Hazards 05/21/99Caustic Chemical HazardsWhile both alkalis and acids cause tissue destruction, acids produce a coagulation necrosis which results in a superficial burn. Alkalis in contrast tend to produce a penetrating tissue destruction. Thus an ingested alkali more frequently causes esophageal bums leading to perforation. Acid ingestion, in contrast, more frequently cause burns in the stomach, particularly in the pyloric region.Photo of Nitric Acid Burn19
65 SummaryRecognizing that there are systems for identifying hazardous chemicals and using them to make everyone in the laboratory aware of the potential dangers of materials is a key to safe chemistry. Remember that the warning labels and systems are usually determined under ideal circumstances and may not reflect real world results. For example, anhydrous ammonia is listed as a non-flammable gas but in the real world it leaches hydrocarbons from everything it contacts and rapidly becomes a “foul” and flammable gas. Knowing the dangers and characteristics of the materials with which you work can help prevent accidents and govern emergency response. The more we learn about these materials the safer we are.
67 ReferencesASE (1996) Safeguards in the School Laboratory (10th ed..), Hatfield: ASE.Borrows, P. (1992) ‘Safety in secondary schools’, in Hull, R. (ed.), ASE Secondary Science Teachers’ Handbook, Hemel Hempstead: Simon & Shuster. (This highlights the common accidents in labs most of which involve chemicals in the eye or mouth or on the body; and describes five ‘main danger areas’ such as burns from alcohol fires and alkali metal explosions.) More recently Borrows has written: ‘Safety in science education’, in Ratcliffe, M. (ed.) (1998).DfEE (1996) Safety in Science Education, London: HMSO.Everett, K. and Jenkins, E. (1991) A Safety Handbook for Science Teachers, London: John Murray.The MSDS Hyperglossary at
68 Glossary Back to Module 29 CFR – OSHA’s Laboratory Standard also known as Title 29 of the Code of Federal Regulations Part 1910, Subpart Z, Section 1450Action Level – a concentration designated in 29 CFR part 1910 for a specific substance, calculated as an eight hour-time weighted average (TWA), which initiates certain required activities such as exposure monitoring and medical surveillance. Action levels are generally set at one half the PEL but the action level may vary from standard to standard.Acute toxicity – is the ability of a chemical to cause a harmful effect such as damage to a target organ or death after a single exposure or an exposure of short duration.American Conference of Governmental Industrial Hygienists (ACGIH) – a non-profit organization consisting of a community of professionals advancing worker health and safety through education and the development and dissemination of scientific and technical knowledge. The ACGIH develops and publishes recommended occupational exposure limits each year called TLVs for hundreds of chemicals, physical agents and biological exposure indices.American National Standard Institute (ANSI) – a non-profit organization that administers and coordinates the US voluntary standardization and conformity assessment system.Biological Materials – Biological or biohazardous materials include all infectious organisms (bacteria, fungi, parasites, viruses, etc.) that can cause disease in humans or cause significant environmental or agricultural impact.Carcinogen - A substance capable of causing cancer. Carcinogens are chronically toxic substances; that is, they cause damage after repeated or long-duration exposure, and their effects may become evident only after a long latency period.Back to Module
69 Glossary Back to Module CAS # - Chemical Abstracts Number – a unique number assigned to a chemical by the Chemical Abstracts Service.CFR – Code of Federal Regulations – contains the listings of all US Federal regulations. The CFR, compiled by the Office of the Federal Register, is divided into 50 titles, which cover broad areas subject to Federal regulation.Chemical Hygiene Officer – an employee designated by the employer who is qualified by training or experience to provide technical guidance in the development and implementation of the provisions of the Chemical Hygiene Plan. Note that these duties can be in addition to the other job functions the employee performs in the laboratory.Chemical Hygiene Plan (CHP) – a plan that addresses specific hazards in the laboratory and is required by OSHA’s Laboratory StandardCorrosive – a substance which causes damage to skin, eyes or other parts of the body on contact. Concentrated acids are examples of corrosive substances.Embryotoxin – a substance which retards the growth or affects the development of an unborn child up to and including deformities and death. Mercury compounds, certain heavy metals, aflatoxin, formamide, and radiation are known embryotoxins.Explosive – means a chemical that causes a sudden, almost instantaneous release of pressure, gas and heat when subjected to sudden shock, pressure, or high temperature.Face velocity – the average velocity of air drawn through the face of a chemical fume hood and generally calculated as the total volumetric exhaust flow rate for the hood divided by the area of the open face, less an adjustment for hood air leakage.Back to Module
70 Glossary Back to Module Irritant – a chemical which may cause reversible inflammation upon contact.Laboratory -Any facility where the "laboratory use of potentially hazardous chemicals" occurs. It is a room where relatively small quantities of potentially hazardous chemicals are used during scientific experimentation.Flammable – means a chemical that falls into one of the following categories:aerosol flammable is an aerosol that when tested by the method in 16 CFR , yields a flame protection exceeding 18 inches at full valve opening, or a flashback (a flame extending back to the valve) at any degree of valve openinggas flammable is a gas that at ambient temperature and pressure, forms a flammable mixture with air at a concentration of 13% by volume or less or a gas that at ambient temperature and pressure, forms a range of flammable mixtures with air wider than 12% by volume, regardless of the lower limit.liquid flammable means any liquid having a flashpoint below 100°F (37.8°C), except any mixture having components with flashpoints of 100°C or higher, the total of which make up 99 percent or more of the total volume of the mixture.solid flammable means a solid, other than a blasting agent or explosive as defined in (a), that is liable to cause fire through friction, absorption of moisture, spontaneous chemical change, or retained heat from manufacturing or processing, or which can be ignited readily and when ignited burns so vigorously and persistently as to create a serious hazard. A chemical will be considered a flammable solid if, when tested by the method described in 16 CFR , it ignites and burns with a self-sustained flame at a rate greater than one-tenth of an inch per second along its major axis.Back to Module
71 Glossary Back to Module FM 200 – a Halon replacement extinguishing agent which is a chemical blend (heptafluoropropane), stored as a liquid within the agent cylinder similar to that of Halon-type cylinders. It will not corrode sensitive electronic equipment, and contains no particulates or oily residues. In fact, it leaves very little residue and is a quite popular extinguishing agent in use today for the protection of computer rooms.Fume Hood - a laboratory device, enclosed on five sides with a moveable sash or fixed partial enclosure on the remaining side; constructed and maintained to draw air from the laboratory and to prevent or minimize the escape of air contaminants into the laboratory; and allows chemical manipulations to be conducted in the enclosure without insertion of any portion of the employee’s body other than hands and arms.Hazardous chemical – the OSHA definition is a chemical for which there is statistically significant evidence based on at least one study conducted in accordance with established scientific principles that acute or chronic health effects may occur in exposed employees. The term "health hazard" includes chemicals which are carcinogens, toxic or highly toxic agents, reproductive toxins, irritants, corrosives, sensitizers, hepatotoxins, nephrotoxins, neurotoxins, agents which act on the hematopoietic systems, and agents which damage the lungs, skin, eyes, or mucous membranes.Hazard Communication Standard – 29 CFR was first enacted on November 25, 1983, by the OSHA. It was later modified with minor changes and technical amendments to take effect March 11, The purpose of the standard is to ensure that chemical hazards in the workplace are identified and evaluated, and that information concerning these hazards is communicated through MSDSs and labels. This standard is also known as the Right-to-Know Law.Back to Module
72 Glossary Back to Module HEPA - high efficiency particulate air filter – is a filter that is manufactured, tested and certified to meet applicable construction and efficiency standards for high-efficiency filters. The filters are manufactured from an ultra-fine glass-fiber medium designed to capture microscopic particles that can easily pass through most other filters by a combination of diffusion, interception, and inertial impaction.Health Hazard - means a chemical for which there is statistically significant evidence based on at least one study conducted in accordance with established scientific principles that acute or chronic health effects may occur in exposed employees.Inergen - It is an inert gas used for fire extinguishment. It is a mixture of three naturally occurring atmospheric gases: 52% nitrogen, 40% argon, and 8% CO2. The Inergen gas curtails and extinguishes fire by lowering the oxygen content beneath the level that supports combustion. But it should be noted that due to the CO2 present in Inergen, the brain continues to receive the same amount of oxygen in an Inergen atmosphere as it would in a normal atmosphere, for reasonable periods of time.Laboratory Scale - Working with substances in which the containers used for reactions, transfers, and other handling of substances are designed to be easily and safely manipulated by one person. Laboratory Standard – a standard (29 CFR ) issued by OSHA addressing occupational exposures to hazardous chemicals in the laboratory. All laboratories must comply with this standard.Back to Module
73 Glossary Back to Module Laboratory use of Potentially Hazardous Chemicals - the handling or use of such chemicals in which all of the following conditions are met:1) Use of laboratory scale.2) Multiple chemical procedures or chemicals used.3) Protective laboratory practices and equipment are available and in common use to minimize the potential for student/teacher exposure to hazardous chemicals.LC50 or lethal concentration 50 – this is a measure of toxicity which corresponds to the concentration in air that kills 50% of the test population. Note that most estimates of human toxicity are based on animal studies, which may or may not relate to human toxicity.LD50 or lethal dose 50 – this is a measure of toxicity which corresponds to the dose required to kill 50% of the test population. Note that most estimates of human toxicity are based on animal studies, which may or may not relate to human toxicity. The LD50 is usually measured in milligrams of the material per kilogram of body weight of the test animal. To estimate a lethal dose for a human based on animal tests, the LD50 must be multiplied by the weight of an average person.Material Safety Data Sheets (MSDS) – is a well-established document for disseminating health and safety information about chemical products to employees, customers, emergency responders, and the public. Information contained in the MSDS includes potential health, safety, and environmental hazards, safe handling practices, and applicable regulatory information.Back to Module
74 Glossary Back to Module National Fire Protection Association (NFPA) private non-profit organization, is the leading authoritative source of technical background, data, and consumer advice on fire protection, problems and preventionOrganic peroxide - an organic compound that contains the bivalent -OO- structure and which may be considered to be a structural derivative of hydrogen peroxide where one or both of the hydrogen atoms has been replaced by an organic radical. Peroxides can be very dangerous materials and may be shock and thermal sensitive. They are also strong oxidizers. OSHA – Occupational Safety & Health Administration is part of the US Department of Labor. Its mission is to save lives, prevent injuries and protect the health of America's workers.Particularly hazardous substance – is defined by OSHA in the Laboratory Standard and includes “select carcinogens” (strongly indicative of causing cancer in humans), reproductive toxins, and substances which have a high degree of acute toxicity.Permissible exposure limit (PEL) - which represents the maximum amount or concentration of a substance that a worker may be exposed to under OSHA regulations. There are ceiling values (at no time should this value be exceeded) and 8-hour time weighted averages (an average value of exposure over the course of an 8 hour work shift)Personal Protective Equipment (PPE) – is all clothing and other work accessories designed to create a barrier against workplace hazards. Examples include safety goggles, respirators, lab coats, etc.Back to Module
75 Glossary Back to Module Pyrophoric – a pyrophoric material is one that ignites spontaneously in air and is derived from the Greek word meaning “fire-bearing”. Many of these materials will also react vigorously with water or high humidity and ignite upon contact.Physical Hazard – A hazard exhibited by certain chemicals due to their physical properties. These chemicals fall into the following classes: combustible liquids, compressed gases, explosives, flammable liquids or solids, organic peroxide, oxidizers, pyrophoric materials, and unstable (reactive) or water reactive materials.Reproductive toxins – per OSHA any chemical that affects the reproductive chemicals which affect the reproductive capabilities including chromosomal damage/mutations and effects on fetuses (teratogenesis).Select carcinogens – per OSHA any substance that meets one of the following criteria:regulated by OSHA as a carcinogenlisted under the category, “known to be carcinogens” in the Annual Report on Carcinogens published in the latest edition by the National Toxicology Program (NTP)listed under Group 1 (“carcinogenic to humans”) by the International Agency for Research on Cancer Monographs (IARC)listed in either Group 2A or 2B by IARC or under the category, “reasonably anticipated to be carcinogens” by NTP and causes statistically significant tumor incidence in experimental animals in accordance with any of the following criteria: after inhalation exposure of 6-7 hours per day, 5 days per week, for a significant portion of a lifetime to dosages of less than 10 mg/m3, after repeated skin application of less than 300 mg/kg of body weight per week, or after oral dosages of less than 50 mg/kg of body weight per day.Back to Module
76 Glossary Back to Module Sensitizer – a chemical which may lead to the development of allergic reactions after repeated exposure.Short term exposure limit (STEL) - which is the concentration employees can be exposed to continuously for a short period of time without suffering from irritation, chronic or irreversible tissue damage, or narcosis of sufficient degree to increase the likelihood of accidental injury, impair self-rescue or materially reduce work efficiency.Standard Operating Procedures (SOP) – is a document that describes the operations, analyses, or actions that are commonly accepted methods or the laboratory prescribed procedures for performing certain routine or repetitive tasks.Target Organ - indicate which bodily organs are most likely to be affected by exposure to a substance. Certain chemicals may bio-concentrate in the liver while other target the brain.Threshold Limit Values (TLV) – are airborne concentrations devised by the ACGIH that represent conditions under which it is believed that nearly all workers may be exposed day after day with no adverse effect. TLVs are advisory exposure guidelines, not legal standards, that are based on evidence from industrial experience, animal studies, or human studies when they exist. There are three different types of TLV's: Time Weighted Average (TLV-TWA), Short Term Exposure Limit (TLV-STEL) and Ceiling (TLV-C).Tort Law – is the law of liability and negligence. It involves that plaintiff who allegedly has been wronged and the defendant who is claimed to have perpetrated the injustice. Tort law deals with issues of property and personal injury law. Mass tort is the process of suing a major defendant on behalf of a large number of plaintiffs. Law suits involving drugs such as Vioxx are examples.Back to Module
77 Glossary Back to Module Toxicity Characteristic Leaching Procedure (TCLP) – is a procedure (Method 1311) performed on a sample within the laboratory to determine whether or not a waste is considered hazardous. A sample is extracted with a buffered acid and the resulting extraction fluid or leachate approximates the fluid that would leach from the sample if it were in a landfill.Toxicity Characteristic (TC) – regulatory limits established for 39 compounds. If a waste analyzed via the TCLP procedure detects any of these compounds above the regulatory limits then the waste is said to exhibit the toxicity characteristic.Water Reactive - these substances are dangerous when wet because they undergo a chemical reaction with water. This reaction may release a gas that is either flammable or presents a toxic health hazard. In addition, the heat generated when water contacts such materials is often enough for the item to spontaneously combust or explode.Back to Module
78 Ignition Temperatures Fuel or ChemicalTemperature(oC)(oF)Acetaldehyde175347Acetone465869Acetylene305581Benzene5601040Bituminous coal300572Butane420788Carbon7001292Fuel or ChemicalTemperature(oC)(oF)Carbon monoxide6091128Coal-tar oil5801076Coke7001292Cyclohexane245473Diethyl ether160320Ethane515859Ethylene490914MoreBack to ModuleFuel Oil No.2256494Fuel Oil No.4262505Heavy hydrocarbons7501382Hydrogen500932Gasoline280536Kerosine210410Isobutane462864Isobutene465869Isooctane447837Isopentane420788Isopropyl Alcohol399750Light gas6001112Light hydrocarbons6501202Methane (Natural Gas)5801076The fMethyl Alcohol385725Naphtha5501022Neoheaxane797425Neopentane842450n-Butane761405n-Heptane419215n-Hexane225437n-Octane220428n-Pentane260500n-Pentene298569Peat227440Petroleum400752Production gas7501382Propane480842Propylene458856p-Xylene530986Toluene530849Semi anthracite coal400752Styrene490914Wood300572Xylene463867
79 Ignition Temperatures Fuel or ChemicalTemperatureFuel or ChemicalTemperature(oC)(oF)(oC)(oF)Ehtyl Alcohol365689Isobutane462864Fuel Oil No.1210410Isobutene465869Fuel Oil No.2256494Isooctane447837Fuel Oil No.4262505Isopentane420788Heavy hydrocarbons7501382Isopropyl Alcohol399750Hydrogen500932Light gas6001112Gasoline280536Methane (Natural Gas)5801076Kerosine210410Methyl Alcohol385725Back to ModuleXylene463867
80 Burn on the feet from acid spill Back to Module
81 Burn on the feet from nitric acid spill Back to Module
82 Burn on the feet from alkali spill Back to Module
83 Quiz SevenThe three parts of a DOT label are the warning word(s), the class number and the:PictographUN Chemical Abstract NumberShape of the label.Chemical abstract number.Back to StartNext Question
84 Quiz SevenIn the warning label above, what hazard does the red 3 refer to?HealthFlammabilityReactivitySpecial HazardsNone of the aboveBack to StartNext Question
85 1994Quiz SevenIn the label shown above, what is the four digit number in the center called?The United Nations Common ID Number.The NA ID Number.The Division Number.The Class Number.None of the above.Back to StartNext Question
86 Quiz SevenIn the picture at right, what must the green cylinder contain by federal law?OxygenNitrogenHydrogenA medical gasThere is no law requiring color coding of cylinders.Back to StartNext Question
87 Quiz SevenAs each teacher receives a new chemical care should be taken to:Protect the label on the container.Confirm that the MSDS is in the Lab three ring binderConfirm that the MSDS is in the administration office.That the chemical is entered into the inventory.All of the above.Back to StartNext Question
88 Quiz SevenWhich section of an MSDS would one reference to determine the trade name of a chemical.Section 1 - IdentitySection 2 – Hazardous IngredientsSection 3 – Physical and Chemical PropertiesSection 9 – Chemical Commerce InformationNone of the above.Back to StartNext Question
89 Quiz SevenThe EPA and the DOT refer to any liquid with an ignition temperature of __________ or less to be flammable.100 degrees F.120 degrees F.140 degrees F.212 degrees F.None of the above.Back to StartNext Question
90 Quiz SevenWhat is the most common way in which chemicals are ingested while at work?As part of an experiment.Through inhalationAlong with food or drinkThrough skin absorptionNone of the aboveBack to StartNext Question
91 Quiz SevenInhaling chemicals is particularly dangerous since the respiratory system:Provides direct access to the blood stream.Contains the largest organ in the body.Provides lymphatic access to the brain.Cannot process gases effectively.All of the above.Back to StartNext Question
92 Quiz SevenThe best way to decontaminate hands while working in the lab is to:Wash with soap and water.Use a neutralizing agent.Use water and a 10% bleach solution.Avoid becoming contaminated in the first place.None of the above.Back to StartNext Question
93 Quiz Seven Toxicologists call anything that enters the body a: Foreign object.Xenobiotic.Teratogen.Mutagen.Xenophobe.Back to StartNext Question
94 Quiz SevenExposure to a lot of poison in a short period of time is called a ___________ exposure:Chronic.Subacute.Acute.Systemic.Dangerous.Back to StartNext Question
95 Quiz SevenEffects that result from chemical exposure and are observable soon after exposure are called:Chronic.Subacute.Acute.Systemic.Dangerous.Back to StartNext Question
96 Quiz SevenChemical that upon adequate exposure can cause birth defects in a developing fetus are called:Carcinogens.Xenobiotic.Teratogen.Mutagen.Irritants.Back to StartNext Question
97 Quiz SevenThe OSHA publishes chemical exposure limits as _______ where the ACGIH publishes _________:PELs, Ceilings.Ceilings, PELs.PELs, TLVs.TLVs, TWAs.TWAs, TLVs.Back to StartNext Question
98 Quiz SevenThat ACGIH exposure limit that represents serious health effects after just 15 minutes of exposure:TLV Ceiling.IDLH.LC50.LD50.None of the above.Back to StartFinish