Chapter 12 Flashcards
Detection monitoring and sampling
Reliable measurements of ‘’’ are necessary for :
Choosing appropriate containment methods
Assessing the potential health effects
Determining need for specific medical monitoring
Selecting appropriate PPE/respirator
Selecting appropriate decontamination methods
contaminants
Two terms of measurement commonly qualify the concentrations of a substance in the atmosphere or any solution they are:
PPM
PBV
Parts per million
Percentage by volume
The term ‘’ is usually used to express extremely low concentrations
Parts per billion p. 458
’’’ hazards generally fall into the following categories x3
Oxygen enrichment or deficiency
Flammability ( percentage of flammable gas in the air)
Toxicity ( measured in parts per million of toxic gas)
Atmospheric
Norma air is composed of approximately:
Oxygen-
Nitrogen
Miscellaneous gases
20.9%
78.1%
1%
Atmosphere containing less than 19.5% oxygen is considered a
Oxygen deficient atmosphere
An atmosphere containing greater than 23.5% oxygen is considered
Oxygen enriched atmosphere p. 459
An oxygen enrich atmosphere greatly increases. What of any fuel within the space
Flammability or explosive potential
For combustibility to occur after a fuel converts into a gasous state the fuel must mix with ?
Mix with air(oxidizer) in the proper ratio
LFL is the minimum concentration of ‘’ and’’ that supports combustion. Concentrations below LFL I said to be. ?
Fuel vapor/ air
To lean to burn
UFL is the concentration above which combustion ‘’’ concentrations above, the UFL are said to be ?
Cannot take place
Too rich to burn
According to WISER methane, flammable range is approximately
5-14 %
5% by volume methane equals
100% LEl, 5% methane is 100% of the flammable concentration p. 460
Most portable gas detectors will alarm at ‘’ of LEL
10%
100 % LEL =
10 % LEL =
1% LEL =
5 %
0.5 %
0.05%
The ‘’ of a substance is the potential of that substance to cause harm, and is only one factor and determining whether it hazard exists
Toxicity p461
a Typical 4 gas detector detects what ?
L
O
CM
HS
LEL
Oxygen
Carbon monoxide
Hydrogen sulfide
If the oxygen is too low, what sensor will not work properly?
LEL
Toxic compounds primarily work as a function of the dose and the concentration of the compound, this principal termed ‘’’ is a key concept and toxicology
Dose – response relationship
What is the most common byproduct of incomplete combustion?
Carbon monoxide p. 462
Poisons and the measurement of toxicity are often expressed on safety data sheets in terms of ‘’’ for Amounts ingested, or absorbed and ‘’’’ for amount inhaled ?
Lethal dose
Lethal concentration
As a general rule, the smaller the value regarding lethal dose/lethal concentration, the more what ‘’’ the substances
Toxic
What indicates the minimum amount of solid or liquid that when ingested, absorbed or injected through the skin will cause death
Lethal dose
Sometimes the lethal dose gets expressed with a percentage, such as LD 50 ( most common) or LD 100 what does the number refer to
The percentage of test subjects that died at that dose
What units are often qualified Lethal Dose measured in:
GPK
MPK
Grams per kilogram
Milligrams per kilogram
What indicates the lowest administered dose of a material capable of causing death?
Lethal dose low
What indicates the minimum concentration regardless of independent of body weight of an inhaled substance that will kill the test group?( 1-4 hours )
Lethal concentration
What indicates concentration at the list value killed half of the test group units ‘’’ often measured in ‘’ x2
Median lethal concentration
Parts per million
Milligrams per cubic meter p. 464
What indicates the lowest concentration of gas or vapor capable of killing a specific species over a specific time?
Lethal concentration low or lcl
What for an organism indicates the dose of a chemical or substance required to incapacitate that organism
Incapacitating dose
Incapacitating varies from ?
Moderate( unable to see difficulty breathing)
Severe( convulsing)
Categories of incapacity doses include
ID 50 -
ID 10
What’s serves as a average exposure to any hazardous gas in the workplace based on an eight hour workday or 40 hour work week it is the maximum exposure without experiencing significant adverse health effects
Time weighted average TWA
What is a allowable average exposure over a short period of time typically 15 minutes that should not be exceed more than four times in a day STEL
Short term exposure limit STEL
What is defined by OSHA as the maximum concentration, healthy adults can be exposed to over a 40 hour work week without adverse effects based on workday: PEL
Permissible exposure limits PEL
What is defined as NIOSH as TWA for up to a 10 hour workday during a 40 hour week: REL
Recommended exposure limit
REL
what Condition poses an immediate hazard to health respiratory, protection is required
Immediate danger to life or health IDLH
D, M, S ‘’ assist in the following mitigation tasks:
Identifying hazard
Determining perimeter and scope of the incident
Determining PPE tools and equipment
Check the effectiveness of defense operations
In the effectiveness of Decon ops
Detect leaks from containers or piping systems
Monitors the contamination levels of Decon or runoff p. 465-6
Detection, monitoring and sampling
As a responder, remember that most gases ‘’’
Sink and display air while only a few rise p. 466
The knowledge skill and ability of individuals using the instrument determines it’s
Effectiveness p. 467
Reason they detector may not provide a usable result in an environment include
Incorrect use
Below detection of threshold
No instrument response
Calibration
Low battery
Temperature and humidity
When responding to an unidentified material. Take a risk base response approach and attempting to identify and characterize the hazard present this includes for:;
C
ER
F
O
OL
R
TM
Corrosion
Exothermic reactions
Flammables
Oxidizers
Oxygen levels
Radiation
Toxic materials
Pay particular attention to low lying areas such as ‘’’’ vapors and gases will likely concentrate
Confined spaces and containers p. 469
Personnel should document monitoring, detections, and sampling results which include:
T
L
#
IU
Time of the reading
Location and level of the reading
Reading obtain
Instrument used
What is a threshold measurement that triggers an action established by AHJ.. often maybe set by OSHA PEL
Action levels
When an ‘’’ or action point is reached, it may trigger what:
Removal of unprotected or unnecessary personeel
Additional monitoring
Alteration or adjustment of PPE
Total evacuation p. 470
action level
Hazardoussolids will usually not travel far unless ? Responders will typically be protected using what ?’’
Blown by wind or dispersed by explosion..
Firefighter protective equipment with SCBA OR NFPA CLASS 3 (OSHA/EPA level B) PPE
Hazardous ‘’’ may vaporize and expand rap, potentially travel, great distances and fill low level and confines spaces. responders at these incidents may need to down the highest respiratory and chemical protection equipment before engaging which is PPE
Liquids
NFPA class 2 PPE ( OSHA/EPA level B)
What can damage and penetrate firefighter protective clothing, and SCB and kill quickly if inhaled ?
Corrosive gases
At Gas release responders should operate with extreme caution and wear what class of NFPa/EPA ppe ?
NFPA class 1 PPE //EPA level a
NFPA class one PPE provides what against fire
Very little protection
When determining what ‘’ is used for detection and monitoring operations responder should consider the following:
Mission of operation
Subjected hazard involved
Instrument reaction
Sensitivity and select
Interference
Training p. 471
Equipment
Considering other factors that may reduce ‘’’, reliability include:
The amount of processing time during each use
Effective elements( moisture temperature atmosphere) may have the instrument
instruments
Most instruments need wide before each use per AHJ ?
Calibration
What ensures sensor’s function Appropriately for alarms and other functions, but it does not test accuracy of the sensor,
Field test or bump test
what is Resetting the memory of an instrument to read normal baseline levels and fresh air
Zero
Avoid ‘’ the instrument in locations with potential containment
Zeroing p. 472 right
What measures the amount of flammable vapors and gases in the atmosphere?
LEL sensor, also known as a combustible gas indicator
Typically devices will sound an alarm at ‘’ of the LEL
10%
LeL sensor is calibrated to a specific flammable gas commonly:
M
P
P
H
Methane
Pentane
Propane
Hexane p.477
Factors that influence ‘’ sensors include:
Catalyst Poison
Concentration exceeding 100% of LEL
Concentrations exceeding the upper explosive limit
Chlorinated hydrocarbons
Oxygen acetylene mixtures
LEL
’’ of LEL sensors include:
Battery power decreasing
Extremely cold weather
Cell phones, magnetic fields, high voltage, lines, radio, and static electricity may interfere with readings
Too little or too much oxygen
Limitations
it’s important to determine if any release material access and oxidizer different types of oxidizers may required different types of detections responders may use ‘’’ that include a reagent to detect organic peroxides..
Oxidizer paper strips
Organic peroxides can ignite ‘’ in certain materials and they are components of ‘’ ?
Explosive polymerization
Homemade explosives
Examples of ‘’’ are triacetone triperozides TATP
hexamethylene diamine HMTD p. 478
homemade explosives
One limitation of test strips is
The responder must be close to material in order to use them
One percent drop in oxygen is equivalent to’'’ppm of something else in air
50,000 ppm p. 479
