The chemical hygiene office at St. Norbert College seeks to create a laboratory experience where students learn how to work safely, by recognizing physical and health hazards and assessing the actual risk it poses.

About Hazards

Recognizing the existence of hazards is central to completing a sufficient analysis. Simply stated, a hazard is a potential for harm. If left uncontrolled, a hazard could result in an injury, illness, loss of property, or damage to the environment.

All chemicals have inherent hazards that can cause harm if they are not handled correctly. Chemists use many methods to minimize and control the riks associated with working with chemicals. To learn how to handle chemicals correctly, you must first be able to identify and understand the hazards present.

Risk is a combination of the likelihood of an unwanted incident occurring, the severity of the consequences if it occurs, and the frequency of exposure to the hazard.

Sign or Symptom?

Would you recognize a sign or symtom of exposure?

Signs of exposure are external and are therefore visible to others. They are objective and in some cases measurable. Some examples of signs are hives, sweeling, an increase or decrease in respiration rate, sneezing, coughing, and watery eyes. Signs are typically temporary and go away when the souce of exposure is removed.

Symtoms of exposure manifest internally and are therefore not obvious or visible to others. They are subjective. Some examples are headaches, dizziness, and pain.

Each newly registered substance is assigned a unique Chemical Abstracts Service (CAS) Registry Number, and each substance has its own hazardous characteristics. There are four broad subclasses of chemical hazard; toxicity, flammability, corrosivity, and reactivity.

Commonly-identified hazards in research activities can be broken into three categories:

Agent

Examples: Carcinogenic, teratogenic, corrosive, pyrophoric, toxic, mutagenic, reproductive hazard, explosive, nonionizing radiation, biological hazard/pathogenic, flammable, oxidizing, self-reactive or unstable, potentially explosive, reducing, water reactive, sensitizing, peroxide forming, catalytic, or chemical asphyxiate.

Condition

Examples: High pressure, low pressure, electrical, uneven surfaces, pinch points, suspended weight, hot surfaces, extreme cold, steam, noise, clutter, magnetic fields, simple asphyxiant, oxygen-deficient spaces, ultraviolent radiation, or laser light.

Activity

Examples: Creation of secondary products, lifting, chemical mixing, long-term use of dry boxes, repetitive pipetting, scale up, handling waste, transportation of hazardous materials, handling glassware and other sharp objects, heating chemicals, recrystallizations, extractions, or centrifuging.

More information from the Chemial Hygiene Plan is found in Sections 6.1 to 6.5.

The following table provides definitions of commonly-encountered hazards as described by the Occupational Safety and Health Administration (OSHA). This list is comprehensive, but not all-inclusive. [Word version]

Type	Hazard or Consequence	Description
Chemical	Acute toxicity (Health Hazard)	Acute toxicity refers to those adverse effects occurring following oral or dermal administration of a single dose of a substance, or multiple doses given within 24 hours, or an inhalation exposure of 4 hours
Chemical	Aspiration hazard (Health Hazard)	Aspiration means the entry of a liquid or solid chemical directly through the oral or nasal cavity, or indirectly from vomiting, into the trachea and lower respiratory system.
Chemical	Carcinogenetic (Health Hazard)	Carcinogen means a substance or a mixture of substances which induce cancer or increase its incidence. Substances and mixtures which have induced benign and malignant tumors in well performed experimental studies on animals are considered also to be presumed or suspected human carcinogens unless there is strong evidence that the mechanism of tumor formation is not relevant for humans.
Chemical	Corrosive to metals (Physical Hazard)	A substance or a mixture that by chemical action will materially damage, or even destroy, metals is termed ”corrosive to metal.”
Chemical	Explosive (Physical Hazard)	An explosive chemical is a solid or liquid chemical which is in itself capable by chemical reaction of producing gas at such a temperature and pressure and at such a speed as to cause damage to the surroundings. Pyrotechnic chemicals are included even when they do not evolve gases.
Chemical	Flammable gas, liquid, solid, or aerosol (Physical Hazard)	Flammable gas means a gas having a flammable range in air at 20 °C and a standard pressure of 101.3 kPa. Flammable liquid means a liquid having a flash point of not more than 93 °C. Flammable solids are solids that are readily combustible, or may cause or contribute to fire through friction. Readily combustible solids are powdered, granular, or pasty substances which are dangerous if they can be easily ignited by brief contact with an ignition source, such as a burning match, and if the flame spreads rapidly. Aerosols are any gas compressed, liquefied or dissolved under pressure within a non-refillable container made of metal, glass or plastic, with or without a liquid, paste or powder. The container is fitted with a release device allowing the contents to be ejected as solid or liquid particles in suspension in a gas, as a foam, paste or powder or in a liquid or gaseous state. Aerosols are classified as flammable if they contain any component classified as flammable according to the GHS criteria for flammable liquids, flammable gases, or flammable solids.
Chemical	Gas under pressure (Physical Hazard)
Chemical	Germ cell mutagenicity (Health Hazard)	A mutation is defined as a permanent change in the amount or structure of the genetic material in a cell. The term mutation applies both to heritable genetic changes that may be manifested at the phenotypic level and to the underlying DNA modifications when known (including, for example, specific base pair changes and chromosomal translocations). The term mutagenic and mutagen will be used for agents giving rise to an increased occurrence of mutations in populations of cells and/or organisms.
Chemical	Organic peroxides (Physical Hazard)	An organic peroxide is an organic liquid or solid which contains the bivalent -0-0- structure and may be considered a derivative of hydrogen peroxide, where one or both of the hydrogen atoms have been replaced by organic radicals.
Chemical	Oxidizing gas, liquid, or solid (Physical Hazard)	Oxidizing gas means any gas which may, generally by providing oxygen, cause or contribute to the combustion of other material more than air does. An oxidizing liquid or solid is a substance which, while not necessarily combustible, may, generally by yielding oxygen, cause or contribute to the combustion of other material.
Chemical	Pyrophoric liquid or solid (Physical Hazard)	A pyrophoric liquid is a liquid which, even in small quantities, is liable to ignite within five minutes after coming into contact with air. A pyrophoric solid is a solid which, even in small quantities, is liable to ignite within five minutes after coming into contact with air.
Chemical	Reproductive toxicity (Health Hazard)	Reproductive toxicity includes adverse effects on sexual function and fertility in adult males and females, as well as adverse effects on development of the offspring. Some reproductive toxic effects cannot be clearly assigned to either impairment of sexual function and fertility or to developmental toxicity. Nonetheless, chemicals with these effects shall be classified as reproductive toxicants.
Chemical	Respiratory or skin sensitization (Health Hazard)	Respiratory sensitizer means a chemical that will lead to hypersensitivity of the airways following inhalation of the chemical. Skin sensitizer means a chemical that will lead to an allergic response following skin contact.
Chemical	Self-heating substance (Physical Hazard)	A self-heating substance is a solid or liquid, other than a pyrophoric substance, which, by reaction with air and without energy supply, is liable to self-heat. This endpoint differs from a pyrophoric substance in that it will ignite only when in large amounts (kilograms) and after long periods of time (hours or days).
Chemical	Self-reactive substance (Physical Hazard)	Self-reactive substances are thermally unstable liquids or solids liable to undergo a strongly exothermic thermal decomposition even without participation of oxygen (air).
Chemical	Skin corrosion or irritation (Health Hazard)	Skin corrosion is the production of irreversible damage to the skin; namely, visible necrosis through the epidermis and into the dermis, following the application of a test substance for up to 4 hours. Skin irritation is the production of reversible damage to the skin following the application of a test substance for up to 4 hours.
Chemical	Specific target organ toxicity (single or repeated exposure) (Health Hazard)	Specific target organ toxicity - single exposure (STOTSE) means specific, nonlethal target organ toxicity arising from a single exposure to a chemical.
Chemical	Substances which, in contact with water emit flammable gases (Physical Hazard)	Substances that, in contact with water, emit flammable gases are solids or liquids which, by interaction with water, are liable to become spontaneously flammable or to give off flammable gases in dangerous quantities.
Electrical	Shock/Short Circuit	Contact with exposed conductors or a device that is incorrectly or inadvertently grounded, such as when a metal ladder comes into contact with power lines. 60Hz alternating current (common house current) is very dangerous because it can stop the heart.
Electrical	Fire	Use of electrical power that results in electrical overheating or arcing to the point of combustion or ignition of flammables, or electrical component damage
Electrical	Static/ESD	The moving or rubbing of wool, nylon, other synthetic fibers, and even flowing liquids can generate static electricity. This creates an excess or deficiency of electrons on the surface of material that discharges (spark) to the ground resulting in the ignition of flammables or damage to electronics or the body’s nervous system.
Electrical	Loss of Power	Safety-critical equipment failure as a result of loss of power
Ergonomics	Strain	Damage of tissue due to overexertion (strains and sprains) or repetitive motion.
Ergonomics	Human Error	A system design, procedure, or equipment that is error provocative. (A switch goes up to turn something off).
Excavation	Collapse	Soil collapse in a trench or excavation as a result of improper or inadequate shoring. Soil type is critical in determining the risk associated with this hazard.
Fall	Slip/Trip	Conditions that result in falls (impacts) from height or traditional walking surfaces (such as slippery floors, poor housekeeping, uneven walking surfaces, exposed ledges, etc.)
Fire/Heat	Burn	Temperatures that can cause burns to the skin or damage to other organs. Fires require a heat source, fuel, and oxygen.
Mechanical/Vibration	Chaffing/Fatigue	Vibration that can cause damage to nerve endings or material fatigue that can result in a critical safety critical failure
Mechanical	Failure	Equipment failure typically occurs when devices exceed designed capacity or are inadequately maintained.
Mechanical	Caught-by/Caught-in	Skin, muscle, or a body part exposed to crushing, caught between, cutting, tearing, shearing items or equipment.
Noise	Hearing Damage	Noise levels (> 85 dBA 8 hr TWA) that result in hearing damage or inability to communicate safety-critical information.
Radiation	Ionizing	Alpha, Beta, Gamma, neutral particles, and X-rays that cause injury (tissue damage) by ionization of cellular components.
Radiation	Non-ionizing	Ultraviolet, visible light, infrared, and microwaves that cause injury to tissue by thermal or photochemical means.
Struck By	Mass Acceleration	Accelerated mass that strikes the body causing injury or death. (Examples are falling objects and projectiles.)
Struck Against		Injury to a body part as a result of coming into contact of a surface in which action was initiated by the person. (An example is when a screwdriver slips.)
Temperature Extreme	Heat/Cold	Temperatures that result in heat stress, exhaustion, or metabolic slow down such as hyperthermia/hypothermia.
Visibility	Limited	Lack of lighting or obstructed vision that results in an error or other hazard.
Weather	Phenomena	Created by snow, rain, wind, and/or ice.

From <https://www.acs.org/content/acs/en/about/governance/committees/chemicalsafety/hazard-assessment/tools/common-hazards.html