TLV Manual Flashcards

Facts From The TLV Book
Terms Definitions
The minimum oxygen requirement is...
19.5% at sea level 148 torr
The TLV for particulates not otherwise specified is...
3 mg/m3 for respirable particles and 10 mg/m3 for inhalants particles.
The BEI(A) is for which class of compounds.
Acetylcholinesterase inhibitors
The BEI(M) is for which class of compounds?
Inducers of methemoglobin.
The BEI(P) is for what class of compounds?
What is the meaning of the inhalant fraction and vapor (IVF)?
It is used when a material exerts sufficient vapor pressure such that it may be present in both vapor and particulate phases and each can contribute significantly to the dose. This is based on the ratio of the saturated vapor conc to the TLV. The footnote is generally used for ratios of 0.1-10.
The IH should consider both particulate and vapor phases to assess exposures from...
From spraying operations, from processes involving temperature changes that may affect the physical state of matter, and when a significant fraction of the vapor is dissolved into or adsorbed on to particles of another substance such as water soluble compounds in a high humidity environment.
The DSEN and RSEN designations stand for...
Dermal and respiratory sensitizers, respectively.
Do the SEN notations imply that these are the critical effects for the TLV?
No. If sen data exist, they are considered.
Does a TLV with a SEN notation protect already sensitized workers?
No. It is designed to protect individuals from being sensitized, but does not protect already sensitized individuals.
What is the significance of the skin notation?
The potential significant contribution to the overall exposure by the cutaneous route, including mucous membranes and the eyes by contact with vapors, liquids, and solids.
Can over exposure occur following dermal contact with liquids and aerosols from chemicals with skin notation, even when airborne concentrations are below the TLV?
Is a skin notation applied to chemicals that cause skin irritation?
No. A skin notation is not applied to chemicals that cause irritant or corrosive effects in the absence of systemic toxicity.
What should be considered to assess the dermal contribution to the dose from a compound with a skin notation?
Biological monitoring. The skin notation indicates that air sampling alone is insufficient to quantify exposure.
A1 carcinogen defined as...
Known human based on epi data
A2 carcinogen defined as...
Suspected human carcinogen. Human data not sufficient, or carcinogenic in animals by relevant doses, routes, sties, tissue type to humans.
A3 carcinogen defined as...
Confirmed animal carcinogen - doses and mechanisms may not be relevant to humans. Epi data are negative.
A4 carcinogen defined as...
Not classifiable as a human carcinogen. Have potential, but inadequate data. In vivo or animal data not sufficient to place in higher category.
A5 carcinogen defined as...
Not suspected as a human carcinogen. Based on properly conducted epi studies or a lack of carcinogenicity in lab animals.
If there are no human or animal carcinogenicity data for a substance, how is it classified.
A compound with no data is not assigned a carcinogenicity designation.
For A1-A3 carcinogens, exposures should be controlled...
To levels as low as possible below the TLV. Eliminate exposure to the fullest extent possible.
The PNOS designation refs to particles that...
Do not have a TLV, are insoluble or poorly soluble in water, and have low toxicity. Or cause toxic effects other than by inflammation or the mechanism of lung overload.
For aerosols or particulate matter, the hazard depends on particle size and mass concentration because...
Particle size determines the deposition site within the respiratory tract, and many occupational diseases are associated with deposition in particular areas of the respiratory tract.
Inhalable particulate matter is defined as...
Particles that are hazardous when deposited anywhere in the respiratory tree.
Thoracic particulate matter (TPM) is defined as...
Particles that are hazardous when deposited anywhere within the lung airways and the gas-exchange region.
Respirable particulate matter (RPM) is defined as...
Materials that are hazardous when deposited in the gas exchange region.
The median cut point for the inhalable fraction is...
100 um
The median cut point for thoracic particulate matter is...
10 um
The median cut point for respirable particulate matter is...
4 um
The ACGIH mixture formula applies to what type of interaction?
Additive. I should be used when the agents have the same target organ or system.
The additive mixture formula for TLVs is...
The sum of each chemical concentration divided by its respective TLV. If the number is greater than 1, then there is an issue.
Full shift additive formulas can involve...
TWAs and ceilings
Short-term additive formulas can include...
STELs and ceilings or the excursion limit (5xTLV)
Can the additive mixture formula apply to sequential expsusures?
Yes, but not for consecutive ceiling exposures.
Exceptions to the additive formula occur when...
There is good reason to believe that the effects are not additive, then there are suspected synergistic effects or potentiation effects. Potentiation is exhibited at high exposures. You can include a synergy factor to adjust.
Can the additive formula be used for complex mixtures?
No. It cannot be used for complex mixtures such as gasoline, diesel exhaust, thermal decomposition products, fly ash, etc...
The onset and severity of symptoms due to oxygen deprivation are affected by many factors including...
Magnitude of oxygen deficiency, exposure duration, work rate, breathing rate, temperature, health status, age, and pulmonary acclimatization.
The initial symptoms of oxygen deprivation occur at a hemoglobin saturation of...
90% and below
At hemoglobin concentrations between 80-90%, what happens?
Healthy individuals compensate or resist hypoxia. In compromised patients oxygen would be prescribed.
What partial pressure of oxygen is needed in the pulmonary capillaries to maintain 90% hb sat?
An alveolar pO2 of 60 torr, which corresponded to 120 torr in the ambient air.
A pO2 of less that 120 torr, what happens to I acclimatized workers?
Symptoms of increased pulmonary ventilation, and cardiac output, incoordination, and impaired attention and thinking. This is incompatible with safe work. Also happens at 5,000 to 7,000 feet above sea level.
What pO2 does ACGIH recommend?
132 torr
The reciprocal calculation serves what purpose?
It is a method for calculating OEL's for refined hydrocarbon mixtures. There are two parts: the calculation methodology, and the group guidance values (GGVs). The RCP calculates an unique OEL based on the mass composition of the mixture.
The RCP is to be used only for...
Hydrocarbon solvents containing saturated aliphatics that have additive effects. The principal effect is CNS depression. It can also include aromatics predominantly of carbon numbers 5-15 derived from petroleum and boiling from 35-320C. Does not apply to HC's with significant toxicity such as benzene, hexane, or methylnaphthalene.
The reciprocal equation for a hydrocarbon mixture is...
GGV of the mixture is equal to 1/ the sum of the liquid mass fraction of each component divided by each component's GGV(guidance value or TLV). The liquid mass fraction is given as a decimal from 0-1.0.
How does the BEI relate to the TLV?
It generally represents the concentration a workers should exhibit if exposed by inhalation at the TLV. It generally indicates a concentration that nearly all workers could be exposed to without adverse health effects.
What are the typical media for biological sampling?
Blood, urine, and exhaled air.
Are all BEIs based on the TLV?
No. Some, such as lead, are based on adverse health effects.
What are some factors that may result in inconsistencies in the BEI and TLV?
Physiological makeup and health status, metabolism, etc...; occupational exposure factors such as work rate intensity and duration, skin exposure, temp and humidity; non-occupational exposure factors, smoking, alcohol, off job exposures; methodological factors specimen collection and deterioration, location of air sampling device in relation to breathing zone, particle size distribution and bioavailability, variable effectiveness of PPE.
A "prior to shift" sample should be collected...
16 hours after exposure ceases
A "during shift" sample should be collected...
Anytime after 2 hours of exposure.
An "end of shift" sample should be taken...
ASAP after exposure ceases.
An "end of the workweek" sample should be taken...
After 4 or 5 consecutive working days with exposure.
A "discretionary" sample should be taken at...
Any time
The urine specimen acceptability criteria for the BEI are...
A creatinine concentration between 0.3 and 3.0 g/l or a specific gravity between 1.010 and 1.030
The BEI notation of "B" means....
Background. Can be present in biological specimens from non-occupational exposure. Background is included in the BEI.
The BEI notation of "Nq" means...
Bio monitoring is recommended, however, the data are insufficient to determine a BEI.
The BEI notation of "Ns" means...
Non-specific, since the analyte can be seen after exposure to other chemicals.
The BEI notation "Sq" means...
Semi-quantitative. The analyte is an indication of exposure tot eh chemical, but quantitative interpretation is ambiguous. This should be used a as screening test or as a confirmatory test.
Does exceedance of a BEI indicate harm?
No. The BEI does not indicate a sharp distinction between haz and non- haz exposures. Look at repeat sampling to see if there is a pattern of exceedance a. If so, look reduce exposure. Dependence should not be placed on one specimens due to the variable nature of bio monitoring.
What is the exposure duration to which BEIs apply?
8 hr day, 5. Days/week the BEI committee does not recommend any adjustment or correction factor regardless of the work schedule.
What are the intended used of the BEI?
A guideline for the control of potential health hazards to the worker and should not be used for other purposes. Not applicable to the general population or for non-occupational exposures. They are not rigid lines of safety or danger, and they are not an index of toxicity.
The TLV limits for infrasound and low-frequency sound are...
An SPL ceiling limit of 145dB and an overall unweighted SPL of should not exceed a ceiling of 150dB. This is for exposures except impulsive sound with durations of less than 2 seconds, one-third octave band. May also use a peak SPL of 145dB for non-impulsive events.
What frequency sounds may cause whole body vibration?
50-60Hz may cause annoyance and discomfort. The SPL of these sounds may need to be reduced.
Noise TLVs are based on...
Protection of the ability to hear and understand normal speech.
The TLV prevents hearing loss at which frequencies?
3,000 and 4,000 Hz
The noise TLVs are designed to protect what proportion of workers?
They are designed to protect the median of the population against noise-induced hearing loss exceeding 2 dB after 40 years of occupational exposure of 0.5, 1, 2, and 3, Hz. A hearing protection program including audiometry is necessary when workers are exposed to noise at or above the TLV.
How do you a count for a mixed exposure when two or more periods of noise exposure are experienced?
Calculate he sum of each invidious noise level duration divided by the respective duration of exposure permitted at that level.
What is the minimum noise level to be considered in a TLV noise calculation?
80 dB
What is the minimum duration needed to calculate the combined effects of noise?
Tree seconds. If noise events are shorter, use a dosimeter or integrating sound meter set with a 3 dBA exchange rate and an 8-hr criteria level of 85 dBA.
What are the requirements for instruments measuring implusive or impact nise
A measurement range between 80-140 dB and a pulse range of a least 63dB.
What is the maximum allowable noise exposure?
A C-weighted SPL of 140 dB. If no instrumentation is available to measure a C-weighted peak, an unweighted peak measurement below 140dB may be used.
What instrumentation should be used to measure the sound TLV?
The sound level meter must meet the requirements of ANSI specification for sound level meters S1.4 Type S2A, and set to A-weighted network with slow response.
A dosimeter or integrated sound level meter is recommended for measuring
Above 120dB
The 8-hr sound level and doubling time for the TLV is?
85 dB and a doubling rate of 3 dB. example, raising the decibel rate by 3dB decreases the corresponding exposure time by 1/2. This can go either way, but stops at 80 dB and 24 hrs/ day.
What standard provides guidance for impulse exposure above a C-weighted level of 140dB?
The MIL-STD-1474C. Provides guidance for single or double protection.
What chemicals can cause hearing loss?
Carbon monoxide, lead, manganese, styrene, toluene, or xylene. When combine with noise exposures, periodic audiograms are advised and should be carefully reviewed. Other ototoxic compounds under investigation include arsenic, carbon disulfide, mercury, and TCE.
Under what conditions may noise cause hearing loss in a fetus?
Noise exposure in excess of a C-weighted 8-hr TWA of 115 dBC or a peak exposure of 155 dBC to the abdomen of pregnant workers beyond the 5th month of pregnancy.
How are the noise limits considered on a weekly basis?
The sum of the fractions on any one day may exceed one; however, the sum of fractions over a 7-day period must be 5 or less and no daily fraction can exceed 3.
What is the background noise level for a worker who is restricted to a workspace that also serves as their place of rest?
When a worker is restricted to areas such as this for more than 24-hours, the background noise level for spaces used for relaxation and sleep should be 70 dBA or below.
What is the retinal hazard region wavelength range for lasers?
400-1400 nm
What is the Ca correction factor for the laser TLV for the eye?
The Ca factor is for wavelengths between 700-1049 nm to account for reduced absorption of melanin.
What is the Cb correction factor for the laser TLV?
The Cb correction factor is for wavelengths from 400-600 nm to account for reduced photochemical sensitivity for retinal injury.
What is the purpose of the Cc correction factor applied to the laser TLV
It is applied to wavelengths from 1150-1400 nm to account for pre-retinal absorption of the ocular media.
What correction factor is to be applied to the skin for the laser TLV?
A Ca factor is to be applied for wavelengths between 700-1400 nm.
The energy cutoff for x-rays being considered ionizing radiation is...
> 12.4 eV whic corresponds to wavelength of less than approx 100 nm.
The justification for radiation exposure to workers is...
No exposure is warranted unless it produces sufficient benefit to the exposed individual or society to offset the detriment it causes.
The optimization of radiation exposure refers to...
Keeping radiation exposure as low as reasonably achievable (ALARA), taking into account economic and social factors.
What is the cancer risk limitation for occupational radiation exposure?
The rad dose from all occupational radiation exposures should not exceed a risk of 10-3 per year of inducing fatal cancer during the lifetime of the exposed individual. This is based on the ICRP and NCRP estimate of a 5% lifetime risk of fatal cancer for and exposure of 1Sv and an annual occupational exposure of 20 mSv averaged over 5 years.
The radiation exposure guideline for effective dose is...
50 mSv in any single year and 20 mSv per year averaged over 5 years.
The annual equivalent radiation dose to the lenses of the eye is...
150 mSv
The annual equivalent radiation dose to the skin, hands, and feet is...
500 mSv
The allowable cumulative effective dose of radiation is...
10 mSv x age in years.
The allowable embryo/fetus monthly equivalent radiation dose is....
0.5 mSv
The guideline for exposure to radon and its daughters is...
4 working level months. A WLM is equal to 3.5 x 10-3 Jh/m3. This is equivalent to an individual worker annual dose of 10 mSv or an upper reference activity of 1500 Bq per m3.
The field of ergonomics is defined as...
As the field that studies and designs the human-machine interface to prevent illness and injury and to improve work performance. It attempts to ensure that jobs and work tasks are designed to be compatible with the capabilities of the workers.
What are some of the important ergonomic considerations?
Force, work duration, repetition, contact stresses, postures, and psychological issues.
Musculoskeletal disorders (MSDs) are defined as...
Chronic muscle, tendon, and muscle disorders caused by repetitive exertions, rapid motions, high forces, contact stresses, extreme postures, vibration, and/or low temperatures.
Other names for MSDs include...
Cumulative trauma disorders (CTDs), repetitive motion illnesses (RMIs), and repetitive strain injuries (RSIs)
What is an unacceptable threshold for discomfort at work?
Discomfort that persists from day to day or interferes with activities of work or daily living.
The major elements of an ergonomic program include...
Recognition of the problem; evaluation of suspected jobs for possible risk factors; identification and evaluation of causative factors; involvement of workers as fully informed active participants; appropriate health care for workers who have developed musculoskeletal disorders.
General programmatic controls that should be implemented when risk of MSDs is recognized include...
Education of workers, supervisors, engineers, and managers; early reporting of symptoms by workers; and ongoing surveillance and evaluation of injury, health and medical data.
What engineering controls could be implemented to eliminate or reduce risk factors on the job...
Using work method engineering, i.e. time study, motion analysis, to eliminate unnecessary motions and exertions. Using mechanical assists to eliminate or reduce exertions to hold tools and work objects. Selecting or designing tools that reduce force requirements, reduce holding time, and improve postures. Implementing quality control and maintenance problems that reduce unnecessary forces and exertions, especially associated with nonvalue-added work.
Administrative controls reduce risk through...
Reduction of exposure time and sharing the exposure among a larger group of workers.
Administrative controls to address ergonomic issues can include...
Implementing work standards that permit workers to pause or stretch as necessary but at least once per hour. Re-allocating work assignments (e.g. Using worker rotation or work enlargement)so that a worker does not spend an entire work shift performing high-demand tasks.
What principals should apply when selecting actions to address MSDs...
Appropriate engineering and administrative controls will vary from industry to industry and company to company. Informed professional judgement is required to select the appropriate control measures. Work-related MSDs typically require periods of weeks to months for recovery. Control measures should be evaluated accordingly to determine their effectiveness.
Non-occupational factors that me be associated with cases of MSDs include
Rheumatoid arthritis, endocrine disorders, acute trauma, obesity, pregnancy, age, gender, level of physical conditioning, previous injuries, diabetes, recreational/leisure activities.
The Hand Activity Level is base on...
The exertion frequency, rest pauses, and the speed of motion. It is a scale from 0-10. 0 is idle and 10 is repaid steady motion that is difficult to keep up with.
The hand activity level TLV is based on...
The hand activity level (HAL) and the normalized peak force.
What is the peak hand force?
The peak force exerted by the hand during each regular work cycle. It can be determined by a trained observer, reading workers using a Borg-like scale, or measured with instrumentation such as strain gauges or electromyography. It is normalized to a scale of 0-10, which corresponds to 0% to 100% of the posture-specific strength for the applicable population. Normalized peak force = (peak force/posture-specific referent strength) x 10.
The brief and scala model is...
TLV reduction factor = 8/Hrs worked x (24-hrs worked)/16
Hand activity level TLVs may be reduced below action levels for the following factors...
Sustained non-neutral postures such as wrist flexion, extension, deviation, or forearm rotation. Contact stresses. Low temperatures. Vibration.
A mono-lifting task is defined as...
One in which the loads are similar and the starting and destination points are similar. The TLV is only applicable to mono-lifting tasks and does not cover other manual material handling tasks such as carrying, pushing, or pulling.
Under what factors should professional judgement be used to reduce weight limits below the recommended TLV?
High frequency lifting >360 lifts per hour. Extended work shifts, lifting for more then 8 hrs per day. High asymmetry, lifting more than 30 degrees from Sagittal plane. Rapid lifting motions with twisting. One-handed lifting. Constrained lower body posture such as sitting or kneeling. High heat and humidity. Lifting unstable objects. Poor hand coupling, lack of handles, cut outs or other grasping points. Unstable footing. During or immediately after whole body vibration at to above the TLV.
What are the three horizontal lifting zones?
Close <30 cm, intermediate 30-60 cm, extended >60-80 cm
What are the vertical lifting zones?
Floor to middle shin, middle shin to knuckle height, knuckle height to below shoulder, and reach limit or 30 cm above shoulder to 8 cm below shoulder. The maximum lifting height is 180 cm above floor level.
The hand arm segmental vibration is designed to protect against...
Nearly all workers will not profs beyond stage -1 of the Stockholm Workshop Classification System for Vibration-induced White Finger (VWF) aka Raynaud's Syndrome of Occupational Origin.
In addition to the TLV, suggested controls for hand-arm vibration syndrome (HAVS) include...
1. Antivibration tools. 2. Antivibration gloves. 3. Proper work practices to keep hands and body warm and minimization of vibration coupling between the worker and the tool, and 4. Medical surveillance program.
Stockholm Workshop HAVS classification system for cold-induced peripheral vascular and sensorineural symptoms stages are...
0 - no attacks; 1- Mild, occasional attacks affecting only the tips of one or more fingers; 2 - Moderate, occasional attacks affecting distal and middle (rarely also proximal) phalanges of one or more fingers; 3 - Severe, frequent attacks affecting all phalanges of most fingers; 4 - Very Severe, as stage 3, with tropic skin changes on finger tips.
The acceleration of a vibration handle or workpiece should be determined...
I three mutually orthogonal directions at a point where vibration enters the hand. The directions should be those for,one the biodynamic coordinate system, but may be a closely related basicentric system. The freq range is 5-1500 Hz. Each component should be frequency-weighted to human response to account for change in vibration hazard with frequency
Vibration measurements should be expressed in which way?
The root mean square (RMS) of the frequency-weighted component accelerations in units of m/s2 or gravitational units (g)' the largest of which a sub K, forms the basis for the exposure assessment.
The whole-body vibration (WBV) TLV is designed to protect against...
Minimum risk of back pain, adverse health effects to the back, and inability to operate a land-based vehicle properly.
Human vibration resonance frequency occurs in what ranges?
The 4-8 Hz frequency in the z-axis, and the 1-2 Hz range for the x and y axes.
The TLV is valid for vibration crest factors of...
Of 6 or less. The crest factor is defined as the ratio of peak to RMS acceleration measured in the me direction over one minute. If the crest actor exceeds 6, the TLV will underestimate the effects of WBV.
The TLV for WBV is not intended for which structures?
Fixed buildings, off-shore structures or ships.
The objective of the cold stress TLV is to...
Prevent the deep body temp from falling below 36 C or 96.8 F and to prevent cold injury to the extremities. For a single occupational to a cold environment, a drop in core temp to no lower than 35 C should be permitted.
What occurs when core temps fall below 36C?
Reduced mental alertness, reduction in rational decision making, and loss of consciousness with potentially fatal outcomes.
When does maximum severe shivering occur?
Core temps below 35 C.
Insulated clothing to maintain core temps above 36 C is required below what ambient temp?
4 C or 40 F.
Severe hypothermia occurs below what core temp?
33 C or 91.4 F
Continuous exposure of exposed skin should not be permitted at wind chill temps of less than...
-32 C or -25.2 F
Superficial or deep local tissue freezing will occur only at temperatures below...
-1 C or 30.2 F regardless of wind speed.
Below what temp is it imperative that workers in wet clothing be provided a dry change of clothes and treatment for hypothermia?
2 C or 35.6 F
Special hand protection is required to maintain dexterity for the prevention of accidents when...
Fine work is conducted with bare hands for more than 10-20 min in temps below 16C (60.8 F). Special provisions should be made to keep hands work i.e. air jets, radiant heaters or contact warm plates. Metal handles should be insulated at temps below -1C (30.2F). If air temp is below 16 C for sedentary, 4 C for light, or -7 C (19.4 F) for moderate work with no fine dexterity required, gloves should be worn.
To prevent frostbite, workers should wear anti-contact gloves and...
When cold surfaces below -7C or 19.4F are within reach, each worker should be warned against inadvertent contact. If the air temp is below -17.5C (0F), hands should be protected by mittens, and machine controls should be designed for mittens.
Provisions for total body protection are required is work is performed at what temp?
At or below 4C.
Workers should wear cold protective clothing appropriate for the level of cold and physical activity:
If he air velocity is increased. By wind, draft, or artificial ventilating equipment, workers should be shielded or wear an easily removable windbreak garment. Workers may wear raincoats for light work; for heavy work, the outer layer may be water repellant and should be changed when wet and should provide ventilation to keep inner layer dry; clothing should be dry before entering cold area; socks and felt insoles should be changed daily. If exposed areas of the body cannot be protected form frost bite, auxiliary heated version of protective items should be used. If available clothing is not protective of frostbite or hypothermia, work should be modified or suspended until weather improves. Workers handling evaporative liquids should take special precautions to avoid soaking of clothing or gloves.
Heated warming shelters should be made available when...
Work is performed continuously in the cold or equivalent chill temps (ECT) below -7C (19.4F). The onset of heavy shivering, minor frostbite, and the feeling of excessive fatigue, drowsiness, irritability, or euphoria are indicates of immediate return to shelter. When entering the shelter, the outer layer of clothing should be removed and the remainder loosened to permit sweat evaporation or dry clothes provided. Dehydration can occur, and warm sweet drinks and soups should be provided for caloric intake and fluid volume. The intake of coffee should be limited due to the diuretic and circulatory effects.
For work at or below -12C (10.4F), the following should apply...
The worker should be under constant protective observation. The work rate should not cause heave sweating resulting in wet clothing, for heavy work, rests should be taken in heated shelters and the opportunity for dry clothing should be provided. New employees should not be required to work full shifts during the first days till acclimated to temps and clothing. Weight and bulk invests of clothing should be included in estimating required work performance and weights to be lifted by the worker. Sitting or standing still for long periods of time should be minimized. Unprotected metal chairs should not be used and workers should be protected from drafts.
Workers should be trained in the following safety and health procedures when working in cold environments...
Proper warming procedures and appropriate first aid treatment. Proper clothing practices, proper eating and drinking habits, recognition of impending frostbite, recognition of signs and symptoms of impending hypothermia or excessive cooling of the body even when shivering does not occur. Safe work practices
Special requirements for refrigerated rooms include...
The air velocity should be minimized as ,ugh as possible and should not exceed 1m/s (200 fpm). Special wind protective clothing should be provided based on existing air velocities.
Cold exposure may require reduced exposure limits for which situations?
Vibration or toxic substances.
Workplace monitoring for cold is required as follows...
Suitable thermometry at any workplace where the environmental temps are below 16C and 60.8F. Whenever the air temp falls below -1C (32.2F), the dry bulb temp should be measured and recorded at least every 4 hours. In indoor workplaces, the wind speed should be recorded at least every 4 hours whenever air flow exceeds 2 m/s (5 mph). In outdoor woke situations, wind speed should be measured when air temp is below -1C (30.2F). The ECT should be recorded with the other data when air movement measurements are required, and recorded when the ECT is below -7C (19.4F).
Employees taking medications or suffering form diseases that reduce cold tolerance below what temps?
-1 C (30.2 F)
The cold temp limits for medical certification are...
Routine exposure to temps below -24 C (-11.2F) with wind speeds below 5 mph or air temps below -18 C (0 F) with wind speeds above 5 mph.
The goal of the heat stress TLV is to...
Maintain the body core temp within + 1 C of normal. This temp can be exceeded under certain circumstances with selected populations, environmental and physiologic monitoring and other controls. The TLV is designed to protected nearly all heat acclimated adequately hydrated heathy workers.
The heat-related action level is designed to...
To protect unacclimated workers and represents a condition where a heat stress management program should be considered.
Heat stress is defined as...
The net load is the net heat load from the combined contributions of metabolic heat, environmental factors (air temp, humidity, air movement, and radiant heat) and clothing requirements.
Mild or moderate heat stress may...
Cause discomfort and may adversely affect performance and safety, but is not harmful to human health.
Heat strain is defined as...
The overall physiological response resulting from heat stress which are dedicated to dissipating excess heat from the body.
Acclimatization is defined as...
The gradual physiological adaptation that improves an individual's ability to tolerate heat stress.
Under what conditions does acclimatization occur?
It requires physical activity under heat stress conditions similar to those anticipated for work.
A worker can be considered acclimatized under what conditions?
After a recent heat stress exposures of at least two consecutive hours (eg 5 of the last 7 days to 10 of 14 days).
Heat acclimatization is lost after...
Noticeable loss occurs after 4 days and may be completely lost in 3-4 weeks.
Clothing adjustment factors for some clothing ensembles include...
Working clothes (long sleeve shirt and pants) and cloth coveralls - no adjustment. Double layer clothing - add 3C to WBGT. SMS Polypropylene coveralls - add 0.5 C. Poly olefin coveralls - add 1 C. Limited-use vapor-barrier coveralls - add 11 C. These values are not applicable to encapsulating suits and cannot be added for multiple layers of clothing. In these instances, physiological signs and symptom monitoring should be followed to assess exposure.
WBGT Is dependent on what factors?
Air temp, radiant heat, air movement, and humidity.
The TLV WBGT ranges for the various work loads are...
Light 31-32.5. Moderate, 28-31.5. Heavy 27.5-30.5 (no 75-100% work cycle). Very heavy 28-30 (only for 0-25 and 25-50% work cycles) the action levels are roughly 3-4 degrees lower for each category.
The metabolic rate for resting is...
115 W. example is sitting.
The metabolic rate for light work is...
180 W. example is sitting with light manual work with hands or hands and arms, and driving. Standing with some light arm work and occasional walking.
The metabolic rate for moderate work is...
300 W. example is sustained moderate hand and arm work, moderate arm and leg work, moderate arm and trunk work, or light pushing and pulling. Normal walking.
The metabolic rate for heavy work is...
415 W. example is intense arm and trunk work, carrying, shoveling, manual sawing, pushing and pulling heavy loads, and walking at a fast pace.
The metabolic rate for very heavy work is...
520 W. example is very intense activity at fast to maximum pace.
The metabolic rate category can be adjusted for body weight by...
Multiplying the estimated metabolic rate by the ratio of the actual BW divided by 70 kg.
What elements should be considered when establishing a heat stress management program?
Training about heat stress and strain, small drinks of cool water every 20 min, encourage employees to report sx of heat-related disorders to a supervisor, encourage self-limitation of exposures, encourage co-worker observation of heat stress, counsel and monitor those taking relevant meds or abuse alcohol or other intoxicants, encourage healthy lifestyles and weight, encourage consumption of salty foods, consider pre-placement medical screening, and monitor the heat stress conditions and reports of heat-related disorders.
Indications of heat strain include...
Sustained heart rate in excess of 180 bpm minus the individual's age. Body core temp greater than 38.5 C (101.3 F) for medically selected and acclimatized individuals, or greater than 38 C (100.4 F) of unselected unacclimitized workers; or recover heart rate at one minute after peak work effort greater than 120 bpm, or there are sx of sudden and severe fatigue, nausea, dizziness, or lightheadedness.
A individual may be at greater risk of heat-related disorders if...
Profuse sweating is sustained over hours, or weight loss over a shift is greater than 1.5% of body weight, or 24-hr urinary sodium excretion is less than 50 mmoles.
What conditions should trigger the initiation of a heat stress program?
1). Heat stress levels that exceed the action limit, or 2). Working in clothing ensembles that limit heat loss.
The key elements in Heat stress hygiene practices are...
Fluid replacement, self-determination of exposures, health status monitoring, maintenance of a healthy lifestyle and adjustment of expectation based on acclimitization state.
Job-specific controls for heat stress include...
Consideration of engineering controls that reduce metabolic rate, provide general air movement, reduce process heat and water vapor release, and shield radiant heat sources. Consideration of administrative controls that set acceptable exposure times, allow sufficient recovery, and limit physiological strain. Consideration of PPE that is demonstrated effective for the specific work practices and conditions at the location.
What are the digs of heat stroke?
Core temp greater than 40 C (104 F). The victim is often manic, disoriented, confused, delirious, or unconscious. Aggressive cooling should be started immediately and emergency care and hospitalization are essential.
Prolonged increases in deep body temp are and chronic exposures to high levels of heat stress are associated with...
Temporary infertility, elevated heart rate, sleep disturbance, fatigue, and irritability.
What core body temp can endanger the fetus in the first trimester of pregnancy?
Biologically-derived airborne contaminants include...
Bio aerosols - airborne particles composed of or derived from living organisms, and VOCs that organisms release. Bioaerosols include microorganisms ( ie culturally, nonculturable, and dead microorganisms) and fragments, toxins, and particulate waste products from all varieties of living things.
Indoor biological contamination is defined as...
The presence of a). Biologically derived aerosols gases, and vapors of a kind and concentration likely to cause disease or predispose humans to disease; b). Inappropriate concentrations of outdoor bioaerosols, especially in buildings designed to prevent their entry; or c). Indoor microbial growth and remnants of biological growth that may become aerosolized and to which humans may be exposed.
The term "biological agent" refers to...
A substance of biological origin that is capable of producing an adverse effect, e.g. An infection or hypersensitivity, irritant, inflammatory, or other response.
The ACGIH recommended approach to bioaerosols relies heavily on...
Visually inspecting buildings, assessing occupant symptoms, evaluating building performance, monitoring potential environmental sources, and applying professional judgement.
There are no TLVs for the following biologically derived contaminants...
A). Total culturally or countable bioaerosols (eg total bacterial or fungi); b). Specific or countable bioaerosols (eg Aspergillus fumigatus); c). Infectious agents (eg Legionella pneumophilia pr Mycobacterium tuberculosis); or d). Assayable biological contaminants (eg endotoxins, mycotoxin, antigens or microbial VOCs).
Culturable bioaerosols are defined as...
Those bacteria and fungi that can be grown in laboratory culture. They are reported a colony forming units (CFUs).
Countable bioaerosols are defined as...
Pollen grains, fungal spores, bacterial cells, and other material that can be counted and identified by microscope.
A TLV has not Ben established for culturable or countable bioaerosols for the following reasons...
1). They do not represent a single entity. They are often complex mixtures. 2). Human responses range from innocuous to serious, even fatal depending on the material and susceptibility. 3). It is not possible to collect and evaluate all components using a single sampling method. Different methods of sample collection and analysis may result in different estimates of culturally and countable bioaerosol concentrations. 4). Exposure-response relationships are not well defined.
Specific TLVs have not been established to prevent...
Hypersensitivity, irritant, or toxic responses.
Reasons for the lack of good exposure-response relationships because...
1). Most data are derived from indicators, not the actual etiology all agent. Most samples are not personnel samples either. 2). There is wide concentration variation, and replicate samples are rarely taken. Most samples are short-term or grab samples and may not predict average concentrations. 3). Often, only a small number of workers is affected. Statistical power of studies is low.
How often can employees be exposed to the STEL?
No more than 4 times per day with 60 min between exposures.
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