Chapter 6 - Industrial Hygiene Flashcards
Industrial Hygiene
Science and art dedicated to the anticipation, recognition, evaluation, and control of workplace hazards that may cause worker injuries or illnesses
Anticipation of hazards
What type of facility/site What type of operations/processes What materials are present Facility schematics for drawings available for review? Standard Operating Procedures SDS sheets available for review
Recognition of hazards
walk-through inspection
Evaluation of hazards
may require specialized sampling equipment for quantification- samples analyzed by accredited laboratory
Control of Hazards
plan of action to eliminate, minimize, or mitigate hazards, which may include engineering controls, administrative controls, or personal protective equipment
Vapors
gaseous form of a substance that is normally a solid or liquid at room temperature
gases
substance that completely occupy a space and can be converted to a liquid or solid by increasing or decreasing temperature
vapor pressure
the pressure that a vapor at equilibrium with a pure liquid at a given temperature exerts to the surrounding atmosphere
Particulate
fine solid or liquid particles, such as dust, fog, mist, smoke, or spray
dust
solid particles generated by mechanical action. Size range from 0.1-30um
fume
airborne solid particles formed by condensation of vapor size range from 0.001 to 1.0 um
mist
suspended liquid droplets generated by condensation (fogs) or atomization
size range 0.01 to 10 um
fibers
particulate with an aspect ration (length to width) of 3.1
Why air sampling?
to determine compliance with regulations to assess worker exposure to monitor implemented control measures to evaluate contaminate emissions documentation for legal reasons
Grab sampling
collecting a known volume of air in a container for laboratory analysis or by a direct-reading instrument
Performed using direct-reading instruments or a known volume of air collected in a container such as a Tedlar Bag, and sent to a laboratory
Personal sampling
Employee wears a sampling device which draws air across a filter media for sample collection which is sent to a laboratory- preferred for measuring employee worker exposure
Area sampling
Uses same type of media as in personal sampling, however, sampling device and media are stationary inside a room
Integrated sampling
Collecting one or more personal air samples to estimate the worker’s 8-hr time-weighted average exposure
Analyzing samples
Use an AIAH accredited laboratory
direct reading
direct reading instruments are calibrated for specific contaminants. Air samples are drawn into the direct-reading instrument and analyzed by several methods, including but not limited to fiber optics, photo ionization detection, or flame ionization detection methods
sampling methodology
determined by AIHA ( American Industrial Hygiene Association) or OSHA (Occupational Safety and Health Administration) (or NIOSH (National Institute of Occupational Safety and Health)
Air sampling pumps
most common equipment used to collect both personal and area samples
draw volumes at known flow rates through a filter/media through means of a pump
Low volume = 100cc/min to 5000 cc/min
high volume = 5000 cc/min - 30,000 cc/min
Piston and Bellow Air Pump
Piston-type- handheld pump to draw a known volume of air across and absorbent tube designed for specific contaminants
Both piston and bellows used for screening purposes during walkthrough surveys of a facility to make an initial assessment of potential exposures
Direct-Reading instruments
permit real time measurements of worker exposure to gases, vapors, aerosols and fine particulates suspended in the air
Multi-gas meter- various sensors installed inside meter and may include oxygen, sulfur dioxide, carbon monoxide, carbon dioxide, hydrogen sulfide and combustible gases.
Need to be calibrated, and personnel must be adequately trained.
Cyclones
Used for respirable fraction of airborne particles
In conjunction with sampling filters and cassettes and air sampling pumps, cyclones are devices that discard larger particles
Filters / Filter media
Used primarily to sample for particulates, such as total and respirable particulates, metals, lead, and zinc and so on
Types include: PVC (poly vinyl chloride) , MCEF (mixed cellulose ester ), glass, matched weighted, tare-weighted
Sorbent tubes
Glass encapsulated tubes with various media inside. Used for sampling gases and vapors.
Sample bags or canisters
used to take grab samples of gases or vapors
Positive or negative pressure can be used to fill bag which is sent to laboratory for analysis
Passive samplers
commercially available sample media which is worn by the worker as a badge- diffusion through static air or permeation through a membrane- badge worn for a documented time, then sealed, and sent for analysis
Sampling pump calibration
sample validity and reproducibility
pumps must be pre and post calibrated using primary or secondary standard
Primary standards- spirometer, bubble burette, electronic soap bubble flow meter
Secondary standards- wet test gas meter, dry gas meter, rotameters
Take a minimum of three measurements which must be +/- 2% of each other - the average of these three readings is your calibrated flow rate
Limit of Detection
lowest level that can be determined to be statistically different from a blank sample
Limit of quantification
concentration level above which quantitative results may be obtained with a certain degree of confidence- can be obtained from the analytical procedure or by consulting the analytical laboratory prior to sampling
Upper measurement limit
the useful limit of (in mg of analyte per sample) of the analytical instrument
If post-sampling flow rate is outside the +/- 5% of the pre-sampling flow rate
Samples must be discarded
Target concentration
Estimate of the airborne concentrations of the contaminant being tested
