[+] BLOCK 4: CHEMICAL CONTROLS - PRACTICE (complete) Flashcards
These cards are sample questions, varying in complexity, that are pulled from every testable unit in Block 4. Not every topic covered is represented here, only samples from each concept. For example, some of the first cards ask about controls, but not every type of control (or control method) is covered. It follows that these cards alone will not be comprehensive enough to be called a complete review.
Used as a means of determining how to implement feasible and effective control solutions. It ranks control measures in the order of their effectiveness and stresses the elimination of the hazards as preferable to the use of personal protective equipment (PPE).
HIERARCHY OF CONTROLS
The methods of control of health hazards in the workplace are divided into three categories: Engineering, Administrative and PPE. The Figure 1 is a representation of the hierarchy of controls.
The term applied when a barrier is interposed between a material, equipment, or process hazard and the property or persons who might be affected by the hazard (e.g., glove box, blast shield).
ISOLATION (CONTROL)
Controls frequently used with existing processes where hazards are not particularly well controlled. They consist of managerial efforts to reduce hazards through planning, training, job rotation, reduction of exposure time and written policies and procedures. These methods for protecting workers have proven to be less effective than engineering controls, requiring significant effort by the affected workers.
ADMINISTRATIVE CONTROLS
Standards developed by OSHA for chemicals where additional protection measures are needed to protect workers - outlined in OSHA General Industry Standard (1910 series, Subpart Z).
SUBSTANCE-SPECIFIC STANDARDS or EXPANDED STANDARDS
- 1910.1001 - Asbestos
- 1910.1002 - Coal tar pitch volatiles
- 1910.1003 - 13 Carcinogens (4-
Nitrobiphenyl, etc.) - 1910.1004 - alpha-Naphthylamine
- 1910.1006 - Methyl chloromethyl ether
- 1910.1007 - 3,’-Dichlorobenzidine
- 1910.1008 - bis-Chloromethyl ether
- 1910.1009 - beta-Naphthylamine
- 1910.1010 – Benzidine
- 1910.1011 - 4-Aminodiphenyl
- 1910.1012 - Ethyleneimine
- 1910.1013 - beta-Propiolactone
- 1910.1014 - 2-Acetylaminofluorene
- 1910.1015 - 4-Dimethylaminoazobenzene
- 1910.1016 - N-Nitrosodimethylamine
- 1910.1017 - Vinyl chloride
- 1910.1018 - Inorganic arsenic
- 1910.1024 - Beryllium
- 1910.1025 - Lead
- 1910.1026 - Chromium (VI)
- 1910.1027 - Cadmium
- 1910.1028 - Benzene
- 1910.1029 - Coke oven emissions
- 1910.1030 - Bloodborne pathogens
- 1910.1043 - Cotton dust
A ____________________ limits access to a work area where specific hazardous chemicals/materials exceed allowable exposure limits (PEL, TWA, action limit, etc.) as stated in the relevant standard.
REGULATED AREA
____________________ disorders are one of the NIOSH’s top 10 leading occupational health problems. These disorders are primarily a result of unprotected exposures to harmful chemical, biological, and physical agents.
DERMATOLOGICAL
Most of the injuries and disease risks from dermatological disorders can be prevented or reduced through the appropriate selection and use of protective clothing.
The net heat load to which a worker may be exposed from the combined contributions of metabolic heat, environmental factors, and clothing requirements.
HEAT STRESS
Mild or moderate heat stress may cause discomfort and may adversely affect performance and safety, but it is not harmful to health. As the heat stress approaches human tolerance limits, the risk of heat-related disorders increases.
The process by which a chemical moves through a material at the molecular level. Individual chemical molecules enter the material and pass between the molecules of the protective clothing.
CHEMICAL PERMEATION
A change in one or more physical properties of a protective material caused by contact with a chemical.
DEGRADATION
Law stating that the amount of air coming in equals the amount of air going out. This can be stated by the equation (Q1 = Q2) where each Q is the volumetric flow rate at a point in the system.
CONSERVATION OF MASS
____________________ is exerted in all directions and is the result of a volume of air occupying the space in the duct. It is the pressure that tends to either collapse (negative) or expand (positive) the ductwork with the greatest amount of pressure near the fan.
STATIC PRESSURE
The amount of airflow required inside a duct to keep a contaminant entrained throughout the system. It is expressed in feet per minute (fpm).
TRANSPORT VELOCITY
In a ventilation system, the __________ generates static pressure and moves the air.
FAN
Velocity pressure is measured on an incline manometer in ________________
a.) Feet per minute (FPM)
b.) Cubic feet per minute (CFM)
c.) Inches of water guage (in wg)
d.) Educated guesses (?)
C.) Inches water guage (in wg)
At the vena contracta, the air velocity has increased and can only come at the expense of SP, which _______________ at the vena contracta.
a.) Increases
b.) Decreases
c.) Remains constant
B.) Decreases
As the air velocity (velocity pressure) goes up, the static pressure decreases.
A combination of supply (make-up air) and exhaust is preferred for proper distribution and
dilution.
TRUE OR FALSE:
Supply is often used alone with satisfactory results, but exhaust alone cannot usually provide proper dilution.
TRUE
Exhaust cannot usually provide dilution, at least some supply (make-up air) is needed.
How many times the air volume of the room is replaced in one hour of time.
AIR CHANGES PER HOUR (ACH)
If we know the room volume (ft3) and the volumetric flow rate (cfm), we can determine our air changes per minute (AC/min) by the equation below. Don’t forget to convert to hours.
What are these?
SMOKE TUBES
Some rooms have a requirement to be under either positive or negative pressure. It can sometimes be difficult to tell what the conditions are because the pressure difference may be very slight. To visualize the direction of air flow, you can use smoke tubes. If the room is under negative pressure, smoke will flow into the room through any opening, such as a space under the door.
A ______________________________ system is designed to capture and remove emissions prior to their escape into the workplace environment. Typically consists of hoods, exhausted enclosures, ductwork, air cleaners, fans, and stacks; a primary means of controlling employee exposure to gases, vapors, and particles in traditional workplaces.
LOCAL EXHAUST VENTILATION (LEV)
Identify this instrument and determine its use.
THERMOANEMOMETER
Used to determine face velocity during survey.
The level of respiratory protection expected to be provided by a properly functioning respirator.
ASSIGNED PROTECTION FACTOR (APF)
These respirators cover the wearer’s mouth and nose. They extend from above the nose to below the chin, creating a tight seal around the lower face. These offer the lowest level of protection for all industrial respiratory protection options.
HALF FACE RESPIRATOR
Respirator component designed to prevent exhaled air from adversely affecting filters, cartridges, and canisters, while allowing air to pass through when inhaling.
INHALATION VALVES
Identify the picture below and determine what they are used for.
PARTICULATE FILTERS
They will protect against aerosols such as dusts, mists, fumes, and other particulate matter, but do not protect against gases or vapors. They may not be used in oxygen deficient atmospheres or in an area designated as IDLH.
