SURVEY
a ... is used to plan a full scale ventilation survey
pre-survey
what are the types of pressure losses
friction, dynamic, and contractions (vena contracta)
... is the area of a cross-section of duct
duct area
What is the hierarchy of controls & give an example of each control
Engineering controls -> administrative controls -> PPE
... is created by temperature differences, wind, etc. while ... is achieved using a fan
natural ventilation & mechanical ventilation
what tool is used to measure face velocity
thermoanemometer
Static pressure is negative ... and ... upstream
-upstream & +downstream
what are the two types of hoods for Local exhaust ventilation
enclosing hood and exterior hood
.... is the time it takes for a chemical to pass through a barrier after contact
breakthrough time
2ppm (The most stringent standard is the Air Force OEL)
a ... is used to ensure a ventilation system is within the design specifications
initial survey
... is the potential energy of the ventilation system, ... is the kinetic energy of the ventilation system, and ... is the sum of these energies
static pressure (SP), velocity pressure (VP), and total pressure (TP)
what are the components of a ventilation system
inlet, duct, air cleaner, fan, outlet
What are the four basic engineering controls
substitution, minimization, isolation, and ventilation
a ... is where a chemical is contained in a controlled environment and access is restricted to only authorized people
regulated area
If a ventalation system has fallen below the paramaters in a routine survey what is the first thing that you should do?
Troubleshoot! (fan rotation direction, RPM, slipping fan belt, clogged ductwork etc.)
... is the measure of air flow in fpm right at the hood, ... is the velocity needed to take contaminates into the system, and ... is the velocity needed to move contaminates through the system
face velocity, capture velocity, transport velocity
What are advantages and disadvantages of Local exhaust ventilation systems
Advantages: low air volume used, cheaper long run, limits spread of contaminant, worker exposure reduced
Disadvantages: expensive installation, limits worker access, false sense of security, and co-localized with source of contamination
.... is when a chemical passes through a barrier that has no holes while ... is when a chemical passes through a barrier with preexisting holes. ... is when the chemical makes its own holes
permeation & penetration. degradation
what are the four causes of friction loss
air velocity, duct material, diameter, & length
How are baseline and routine surveys different
baseline ensures that the system is capable of controlling a hazard below the OEL (survey in combination with air sampling), routine survey is done periodically and ensures the system is within parameters
explain what volumetric flow rate is
the measurement of the volume of air flowing through a specific point in the ventilation system. measured in cubic feet per minute (cfm)
what are the advantages and disadvantages of a dilution ventilation system
advantages: usually lower installation costs, requires less maintenance, effective control for small amounts of low toxicity chemicals, not co-located with source of contamination
Disadvantages: does not completely remove contaminants, cannot be used for high toxicity chemicals, infective for large amounts of dust, fumes, gases, ineffective for surges
For chemicals where additional protection measures are needed, OSHA has developed .... sometimes referred to as ....
substance-specific standards or expanded standards
CONTROL A CHEMICAL HAZARD