Acute Effects
Results from a single dose or exposure to a material. Signs and symptoms may be immediate or may not be evident for 24 to 72 hours after the exposure.
Acute Exposure
An immediate exposure such as a single dose that might occur during an emergency response.
Acute Emergency Guidelines
Developed by The National Research Council’s Committee on Toxicology to provide uniform exposure guidelines for the general public.
Chronic Effects
Resulting from a single exposure or from repeated doses or exposures over a relatively long period of time.
Chronic Exposure
Low exposure repeated over time, such as responding to a number of hazmat emergencies while serving as a member of a public safety HMRT or conducting on-scene investigations of hazmat incidents over many years.
Dose. Response Relationship
The cause/effect relationship relating to a substance absorbed by the body and the body’s response to that substance.
Emergency Response Planning Guidelines (ERPG)
Air concentration guidelines for single exposures to hazardous materials.
Exposure
Contact with a chemical.
Medical Surveillance Program
The cornerstone of an effective employee health and safety management system. The primary objectives are (1) to determine an individual can perform his or her assigned functions and (2) to detect any changes in the body system functions caused by physical and/or chemical exposures.
Permissible Exposure Limit
Maximum time weighted concentration at which 95% of exposed health adults will suffer no adverse effects over a 40 hour work week, based on a 8 hour time-weighted average concentration.
Recommended Permissible Limite
Maximum time weighted concentration at which 95% of exposed health adults will suffer no adverse effects over a 40 hour work week, based on a 10 hour time-weighted average concentration.
Short Term Exposure Limit
The 15-minute time weighted average exposure that should not be exceeded at any time, nor repeated more than four times daily with a 60 minute rest period required between each STEL exposure.
Threshold Limit Value/Skin
Indicates a possible and significant contribution to overall exposure to a material by absorption through the skin, mucous membranes. and eyes by direct or airborne contact.
Threshold Limit Value / Time Weighted Average
The maximum airborne concentration of a material to which an average healthy person may be exposed repeatedly for 8 hours each day, 40 hours per week without suffering adverse effects.
Toxicity
The ability of a substance to cause injury to a biological tissue.
Toxicology
The study of a chemical or physical agents that produce adverse responses in the biological systems with which they interact.
