Chemical Hazard and Alternatives Toolbox
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Vocabulary

ChemHAT lightbulb logo wearing graduation capAbsorption
When chemicals enter the body through the skin and pass into the bloodstream. Different parts of the body absorb chemicals at different rates.
Acute exposure
A one-time or infrequent exposure to a chemical
Acute health effects
An adverse health effect that has severe symptoms developing rapidly and caused by exposure to a substance
Additive effect
If the health or environmental impact of two chemicals is equal to the sum of the impact of each chemical separately, that is an additive effect, and usually occurs if two chemicals are acting on human health and the environment in the same way
Aggregate exposure
Risk assessment and occupational exposures have traditionally focused on the exposure of a single chemical or exposure via a single pathway (e.g. inhalation, skin contact, etc.) In reality, most of us are exposed to a mixture of chemicals in a variety of different ways. A measure of aggregate exposure assesses our exposure to a single chemical by multiple pathways. New models of exposure assessment are being developed that take both aggregate and cumulative exposures into account when calculating our chemical exposure burden. (See definition for cumulative exposure).
Allergy
An abnormal response of a person’s body to a chemical or physical hazard.
Benign
Not malignant. A benign tumor is one which does not metastasize or invade tissue.
Carcinogen
A substance or agent capable of causing or producing cancer in mammals, including humans. A chemical is considered to be a carcinogen if: a) it has been evaluated by the International Agency for Research on Cancer (IARC) and found to be a carcinogen or potential carcinogen; or b) it is listed as a carcinogen or potential carcinogen in the Annual Report on Carcinogens published by the National Toxicology Program (NTP) (latest edition); or c) it is regulated by OSHA as a carcinogen
CAS
Chemical Abstracts Service is an organization under the American Chemical Society. CAS abstracts and indexes chemical literature from all over the world in “Chemical Abstracts.” “CAS Numbers” are used to identify specific chemicals or mixtures.
Ceiling limit
An airborne concentration of a toxic substance in the work environment that should never be exceeded
Chemical cartridge respirator
A respirator that uses various chemical substances to purify inhaled air of certain gases and vapors. This type of respirator is effective for concentrations no more than ten times the TLV of the contaminant, if the contaminant has warning properties (odor or irritation) below the TLV
Chemical combinations (effects of)
The effects of two or more chemicals may combine in either an additive or synergistic way. If the health or environmental impact of two chemicals is equal to the sum of the impact of each chemical separately, that is an additive effect, and usually occurs if two chemicals are acting on human health and the environment in the same way. A synergistic effect occurs when the two chemicals together create an effect that is greater than either of the chemicals alone. This can occur when one chemical exposure enhances the impact of another chemical, creating a health or human impact that is greater than the individual chemicals alone.
Chronic exposure
Repeated or prolonged exposure to a substance
Chronic health effect
An adverse health effect with symptoms which develop slowly over a long period of time or which recur frequently.
Combustible liquid
Chemical in a liquid form that has a flash point at or above 37.8C (100F)
Concentration
The amount of a given substance in a stated unit of measure. Common methods of stating concentration are percent by weight or by volume, weight per unit volume, etc
Contact dermititis
Inflammation of the skin that causes red, itchy, blistered, hardened or flaky skin
Corrosive
A substance that causes visible destruction or permanent changes in human skin tissue at the site of contact
Cumulative exposure
Risk assessment and occupational exposures have traditionally focused on the exposure of a single chemical or exposure via a single pathway (e.g. inhalation, skin contact, etc.) In reality, most of us are exposed to a mixture of chemicals in a variety of different ways. Cumulative exposure refers to the sum of all exposures to multiple chemicals. New models of exposure assessment are being developed that take both aggregate and cumulative exposures into account when calculating our chemical exposure burden.
Cutaneous
Affecting the skin
Dermatitis
Inflammation of the skin from any cause
Dermatosis
A broader term than dermatitis; it includes any cutaneous abnormality, thus encompassing folliculitis, acne, pigmentary changes and nodules and tumors
Dose-response relationship
Correlation between the amount of exposure to an agent or toxic chemical and the resulting effect on the body
Dusts
Solid particles generated by handling, crushing, grinding, rapid impact, detonation and decrepitation or organic or inorganic materials.
Dyspnea
Shortness of breath, difficult or labored breathing
Fume
Airborne particulate formed by the evaporation of solid materials, e.g., metal fume emitted during welding. Usually less than on micron in diameter
Gas
A state of matter in which the material has very low density and viscosity. A gas can be changed to the liquid or solid state only by the combined effect of increased pressure and decreased temperature.
HEPA filter
(High Efficiency Particulate Air Filter). A disposable, extended medium, dry-type filter with a particle removal efficiency of no less than 99.97 percent for 0.3 micrometer particles.
Hierarchy of Controls
A means for determining how to implement feasible and effective controls to protect workers. In order of most protective to least effective, the hierarchy is: elimination, substitution, engineering controls, administrative controls, and personal protective equipment
Highly Toxic

Chemicals that are highly toxic

  • cause cancer;

  • cause reproductive damage;

  • cause an allergic reaction;

  • cause eye, nose, throat, skin and/or lung burns or sorrosion at moderate levels of exposure;

  • can cause serious harm, but has no warning properties like a color or odor; or

  • causes damage to any organ or tissue (lungs, liver, kidneys, bladder, central nervous system, blood or any part of the body)

Hormone disruptors or endocrine disruptors
Chemicals that interfere with the hormone system of humans and other animals. Hormone disruptors frequently block or mimic the action of hormones such as estrogen or androgen. These disruptions can cause cancerous tumors, birth defects and developmental disorders, including brain development and learning problems, and impacts on sexual and reproductive development.
IARC
International Agency for Research on Cancer
IDLH
Immediately Dangerous to Life and Health. An atmospheric concentration of any toxic, corrosive or asphyxiant substance that poses an immediate threat to life or would cause irreversible or delayed adverse health effects or would interfere with an individual’s ability to escape from a dangerous atmosphere.
Ingestion
When chemicals enter the body through the mouth by eating or drinking
Inhalation
When chemicals enter the body by breathing in a substance in the form of a gas, vapor, fume, mist or dust
Insoluble
Incapable of being dissolved in a liquid.
Irritant
A chemical, which is not corrosive, but which causes a reversible inflammatory effect on living tissue by chemical action at the site of contact.
Latent period
The time that elapses between exposure and the first manifestation of damage
Malignant
As applied to a tumor. Cancerous and capable of undergoing metastasis, or invasion of surrounding tissue.
Mists
Suspended liquid droplets generated by condensation from the gaseous to the liquid state or by breaking up a liquid into a dispersed state; such as by splashing, foaming or atomizing. Mist is formed when a finely divided liquid is suspended in the air.
MSDS
Material safety data sheet. These must be developed by the chemical manufacturer for each chemical. They must be in English and include information regarding the chemical’s identity and properties, known health effects, exposure limits, whether the chemical is considered a carcinogen by certain classifications, precautionary measures, emergency and first aid procedures, and the name of the company that prepared the sheet. MSDS’s can be difficult to understand.
Mutagen
A substance that can cause changes in the genetic material (DNA) of a cell. These changes are mostly related to cancer, but if the changes occur in the DNA of sperm or egg cells, then these changes can be passed along to future generations.
NIOSH
The National Institute for Occupational Safety and Health is a federal agency. It conducts research on health and safety concerns, tests and certifies respirators and trains occupational health and safety professionals
NTP
National Toxicology Program. The NTP publishes an annual report on carcinogens
OSHA
Occupational Safety and Health Administration, which is part of the U.S. Department of Labor.
Particulate matter
A suspension of fine solid or liquid particles in air, such as dust, fog, fume, mist smoke or sprays. Particulate matter suspended in air is commonly known as an aerosol.
PEL
Permissible exposure limit. An exposure limit that is published and enforced by OSHA as a legal standard.
Personal Protective Equipment
The last line of defense to protect workers from exposure to hazards. PPE should be used in conjunction with engineering and administrative controls. It includes items such as hard hats, goggles, face shields, steel-toed shoes, respirators, aprons, gloves, and full body suits.
Reproductive hazards
Chemicals that affect either the male or female reproductive system or a developing fetus.
Route of entry
The path by which chemicals can enter the body. There are three main routes of entry: Inhalation, ingestion and skin absorption.
Sensitizer
A substance which on first exposure causes little or no reaction but which on repeated exposure may cause a marked response, not necessarily limited to the contact site. Skin sensitization is the most common form of sensitization in the industrial setting.
Short-term exposure limit (STEL)
ACGIH-recommended exposure limit which is the maximum concentration to which workers can be exposed for a short period of time (15 minutes) for only four times throughout the day with at least one hour between exposures.
Solvent
A substance , usually a liquid, in which other substances are dissolved. The most common solvent is water.
Synergistic effect
This occurs when the two chemicals together create an effect that is greater than either of the chemicals alone. This can occur when one chemical exposure enhances the impact of another chemical, creating a health or human impact that is greater than the individual chemicals alone.
Teratogen
Substances which can cause birth defects in the developing fetus.
Vapor
The gaseous form of substances that are normally in the solid or liquid state (at room temperature and pressure. The vapor can be changed back to the solid or liquid state either by increasing the pressure or decreasing the temperature alone. Vapors also diffuse.