Chapter 11 Flashcards
Exposure limits refer to values expressing the maximum dose or concentration to which individuals should be exposed given a specific time frame.
Exposure limits
Milligrams per cubic meter - Expresses concentrations of dusts, gases, or mists in air.
Milligrams per cubic meter
Grams per kilogram - Denotes grams of a substance dosed per kilogram of animal body weight.
Grams per kilogram
Exposure limit - Maximum length of time an individual can be exposed to an airborne substance before injury, illness, or death occurs.
Exposure limit
Concentration - Quantity of a material in relation to a larger volume of gas or liquid.
Concentration
Milligrams per kilogram - Toxicological dose that denotes milligrams of a substance dosed per kilogram of animal body weight.
Milligrams per kilogram
Micrograms of material per liter of air - Describes concentrations of chemicals in air.
Micrograms of material per liter of air
Milligrams per liter - Expresses concentrations of chemicals in water
Milligrams per liter
Parts per milion - May describe the concentration of a gas or vapor in air or the concentration of a specific material in a liquid or solid.
Parts per milion
Threshold limit value - Concentration that can be tolerated during 8 hour workdays.
Threshold limit value
Short-term exposure limit - Concentration that can be tolerated for 15 minutes at a time, provided an appropriate interval between exposures.
Short-term exposure limit
Threshold limit value ceiling - Concentration that should not be exceeded during 8 hour workdays.
Threshold limit value ceiling
Permissible exposure limit - Concentration at which most people are not adversely affected.
Permissible exposure limit
The knowledge, skills and ability of the individual using the instrument determine the effectiveness of that instrument.
effectiveness
Instrument response time - Elapsed time between the movement of an air sample into a monitoring device and the reading provided to the user.
Instrument response time
In order to accurately assess the environment, consider instrument response time.
instrument response time
At WMD or criminal incidents, personnel who conduct sampling activities must follow evidence preservation and chain of custody procedures.
evidence preservation
Regardless of the mission, hazardous materials incidents will always require size up and risk assessment.
risk assessment.
In the U.S., OSHA 29 CFR 1910.120(q) requires detection and monitoring before entry into potentially hazardous atmospheres.
1910.120(q)
Responders may consult resources to understand the hazards and properties of the materials involved and to develop an appropriate risk based response.
risk based response
When dealing with unknown materials, take an analytic approach in attempting to identify and characterize the hazards present.
analytic approach
Detection devices do not provide accurate readings if used in an oxygen deficient atmosphere
oxygen deficient
Understand the limitations of the instruments and detection devices. Follow manufacturers instructions for calibration and usage.
calibration
Action levels can be defined as a response to known or unknown chemicals or products that will trigger some action.
Action levels
Responders at a hazmat incidents involving hazardous solids will typically be sufficiently protected when using firefighter protective equipment with SCBA or level C PPE for monitoring and sampling activities.
C
Action levels trigger specific actions such as donning SCBA or evacuating the area.
Action
Ensure usability before selecting devices.
usability
Field tests may include calibration tests and zeroing
Field tests
The cost of the instrument does not determine its effectiveness.
cost
To determine the appropriate risk based response for identifying hazards in the field, responders should follow the sop of the AHJ.
risk based response
The primary equipment used to detect and measure corrosivity are pH meters and pH paper.
pH
the concentration of hydronium or hydroxide ions in a solution determines the solution’s pH.
hydronium or hydroxide
Acidic substances have excess hydronium ions and pH less than 7.
Acidic
Basic substances have excess hydroxide ions and a pH greater than 7.
Basic
As pH levels increase above 7, compounds become more alkaline.
alkaline
As pH levels decrease below 7, compounds become increasingly acidic.
acidic
Hydronium - Water molecule with an extra hydrogen ion.
Hydronium
Hydroxide - Water molecule missing a hydrogen ion.
Hydroxide
Acidic an basic solutions usually consist of chemicals dissolved in water.
water
The ration of the amount of chemical to the amount of water determines the solutions concentration.
concentration
Generally, the higher concentration, the more damage the acid or base will do relative to itself.
relative to itself
Although they have similar pH, sodium hydroxide will be far more caustic than sodium bicarbonate because it releases more hydroxide ions in solution.
caustic
pH paper is designed to change color when it comes into contact with corrosive materials.
corrosive materials
A pH of 1 is 1,000,000 times more acidic than a pH of 7 while a pH of 13 is 1,000,000 times more alkanline.
1,000,000
Many hydrocarbons may appear to give a reading between 4-6, but this is not a true measure of corrosivity.
4-6
Of all the chemical elements, Fluorine is the most reactive.
Fluorine
In the presence of fluorides, the pinkish red paper turns yellowish white.
yellowish white
Organic peroxides can initiate explosive polymerization in certain materials, and they are components of improvised explosives such as triacetone triperoxide and hexamethylene triperoxide diamine.
Organic peroxides
Potassium iodide starch paper can be used to test peroxides and or potential explosives.
Potassium iodide
Normal air contains 20.9% oxygen, 78.1% nitrogen and 1% other gases.
nitrogen
Because a contaminant will displace air proportionally, a one percent drop in oxygen is equivalent to 50,000 ppm of something else in the air.
50,000
Oxygen sensors should be zeroed in clean air at the elevation of the incident.
zeroed
Large amounts of radiation exposure are usually expressed in a unit called Roentgen equivalent in man, smaller amount of radiation exposure may be described in millirem.
Roentgen equivalent in man
Roentgen - Only measure exposure to gamma and X-ray radiation.
Roentgen
Radiation absorbed dose - Express the amount of radiation energy absorbed by a material.
Radiation absorbed dose
Roentgen equivalent in man - Express the absorbed dose equivalence as pertaining to a human body.
Roentgen equivalent in man
For gamma and X-ray radiation, apply the following common conversion factor among exposure, absorbed dose, and dose equivalent: 1 R = 1 rad = 1 rem
1 R = 1 rad = 1 rem
The SI unit used to measure absorbed dose is called gray whereas the unit for dose equivalence is sievert.
gray, sievert
Millirem - One thousandth of one rem.
Millirem
roentgen - used to measure radiation exposure; applied only to gamma and X-ray radiation.
roentgen
radiation absorbed dose - unit used to measure the amount of radiation energy absorbed by a material.
radiation absorbed dose
Sievert - measurement for low levels of ionizing radiation and their health effect in humans
Sievert
Gray - ionizing radiation dose, defined as the absorption of one joule of radiation energy per one kilogram of matter.
Gray
The two general categories of detectors are gas filled detectors and scintillation detectors.
scintillation
Ion chambers often use ambient air as the detection gas, which can cause them to be affected by temp and humidity.
temp and humidity
GM tubes with sealed metal body are better suited for measuring penetrating gamma radiation that can be an external exposure hazard.
gamma
The crystal in a scintillation detector will produce a small flash of light when interacting with radiation.
flash of light
Dosimetry devices help wearers keep track of their total accumulated radiation dose.
Dosimetry
Toxic compounds produce an effect primarily as a function of the dose and the concentration of the compound.
concentration
This principle, termed the dose response relationship, is a key concept in toxicology.
dose response relationship
The severity of the toxic effect also depends on the duration of exposure, a factor that influences the dose of the compound in the body.
duration of exposure
toxicity is also a factor of exposure over time.
toxicity
An exposure to 200 ppm of a toxin over the course of 10 minutes will have more exaggerated effects than a cumulative exposure to 200 ppm of a toxin over the course of 48 hours.
48
Dose response relationship - Comparison of changes within an organism per amount, intensity, or duration of exposure to a stressor over time.
Dose response relationship
Solvent - A substance that dissolves another substance resulting in a third substance.
Solvent
As a chemical dose increases, the toxic response increases.
toxic response
Poisons and the measurements of their toxicity are often expressed, on safety data sheets, in terms of lethal dose for amounts ingested and lethal concentration for amounts inhaled.
lethal dose, lethal concentration
A typical four gas monitor will detect LEL, oxygen, carbon monoxide, and hydrogen sulfide.
hydrogen sulfide
Ionization potential - Energy required to free an electron from its atom or molecule.
Ionization potential
Detection of ionization may require several steps, and some materials may require the use of correction factors.
correction factors
