|
Overview
Introduction
This document summarizes exposure data
collected by OSHA between mid-September and mid-December
2005, in the region impacted by hurricanes Katrina,
Rita, and Wilma. Response and recovery operations
occurred over a large physical area and encompassed
a wide range of specific activities and operations.
OSHA collected exposure data for a limited subset
of these operations, specifically those performed
regularly during the period covered by this summary:
- Debris reduction, recycling, and disposal*
- Tree trimming
- Restoring electrical utilities
- Locating and establishing temporary housing facilities
- Building demolition
- Sand/sludge removal
- Roof inspection, tarping, and repair
- Assessment, cleanup, and repair of structures
- Roadway and bridge inspection and repair
* Although all the listed
operations occurred regularly during this period,
debris reduction, recycling, and disposal were the most prominent
tasks and, therefore, were the activities where
OSHA most frequently evaluated worker exposures.
Operations conducted during the initial response,
such as floodwater removal and search and rescue,
are not represented in the data summarized here.
Nor does this summary include operations that had
not begun as of mid-December 2005, such as large-scale demolition of homes and structures, including
those built with asbestos-containing materials.
Limitations and Disclaimer
The Matrix does not provide an in-depth analysis of OSHA standards and
regulations and cannot address all hazards. It does not increase or diminish any OSHA requirement
or employer obligation under those requirements. It is intended as a guide and quick reference
for employers and response and recovery workers. The Matrix captures major activities involved
in hurricane response and recovery, highlights many of the hazards associated with them, and
recommends "best practices." Employers must evaluate the specific hazards associated
with the job/operation at the site where the work is being performed.
Employers are responsible for providing a safe and healthful workplace
for their workers. OSHA's role is to assure the safety and health of America's workers by
setting and enforcing standards; providing training, outreach, and education; establishing partnerships;
and encouraging continual improvement in workplace safety and health.
The Hazard Exposure and Risk Assessment Matrix for Hurricane Response
and Recovery Work provides a general overview of particular topics related to current OSHA standards.
It does not alter or determine compliance responsibilities in OSHA standards or the Occupational Safety and Health Act of 1970, or the equivalent State
Plan standards and requirements. Because interpretations and enforcement policy may change over time,
you should consult current OSHA/State Plan administrative interpretations and decisions by the
Occupational Safety and Health Review Commission and the courts for additional guidance on OSHA
compliance requirements. Employers should modify their procedures as appropriate when additional,
relevant information becomes available.
Noise and Air Monitoring Data and Assumptions
OSHA monitored the exposures
of hurricane response and recovery workers to a variety
of hazards including noise, dust (particulates),
silica, asbestos, gas and vapors, and metals. The
results of current hurricane-related worker sampling
can be found on OSHA's
Website. These results are updated regularly.
Sample results that were obtained over a period of less than 8
hours are extrapolated to provide an 8-hour time-weighted average
(TWA) by assuming that the
same level of exposure continued for the full 8-hour shift.
The exposure results obtained by OSHA suggest
that during the period covered by this summary,
hurricane response and recovery workers routinely
experienced noise, dust, or silica exposure when
they performed certain tasks such as debris collection,
debris reduction, site clearing, and activities
such as transportation restoration and the operation
of equipment such as chippers, chain saws, industrial
vacuums, heavy equipment, and related machinery.
Noise Exposure Results Summary
- Twenty percent
of the 324 workers evaluated had noise exposure
levels above OSHA's
permissible exposure limit (PEL) of 90 decibels
(dBA). Over 40 percent of the sampled workers
were exposed to noise levels of 85 dBA or higher.
- Hazardous levels of noise exposure were particularly
common among response and recovery workers involved in debris collection,
debris reduction, site clearing, and transportation
restoration activities. Some of the highest
noise exposures (above the PEL of 90 dBA) were
associated with operating heavy equipment,
chippers, chain saws, and industrial vacuums.
These overexposed workers must wear earplugs
or earmuffs to help prevent hearing loss.
- When workers are
exposed to hazardous levels of noise, employers
must enroll the workers in a hearing conservation
program, similar to the one outlined in 29
CFR 1910.95(c), OSHA's
standard on occupational noise exposure.
- See detailed results of noise sampling.
Dust
Exposure Results Summary
- Over 5 percent of all the 217 workers evaluated
experienced dust exposure that exceeded the
PEL, with another 10 percent at or above the
action level (usually defined as half of an
established occupational exposure level, such
as the PEL).
- The results suggest that heavy equipment
operators were the group most consistently
exposed to high levels of dust. Among those
operators evaluated, more than one-third were
exposed above the action level for dust (usually
defined as half of an established occupational
exposure level, such as a PEL).
- Most of highest dust exposure levels were
measured while collecting and reducing
debris or clearing sites (including grading
operations).
- Dust control methods should be used more
frequently during the dusty tasks, such as
operating chippers and heavy equipment.
- To suppress dust and reduce worker exposure,
some employers moisten materials with a water
mist, use climate-controlled or enclosed cabs,
use tools equipped with suction ventilation
or wetting mists to capture or suppress dust
before it spreads, and have workers stand up-wind
from the dust source whenever practical.
- See detailed results of dust/particulates sampling.
Silica Exposure Results Summary
- Air sampling results indicated that about
20 percent of the 276 workers sampled worked
in an area where silica exposure levels exceeded
the action level. Eleven percent were exposed
above the OSHA PEL for crystalline silica.
- Nearly two-thirds of the sawing/grinding
machine operators evaluated were exposed
to silica dust concentrations at or above the action level
(usually defined as half of an established occupational exposure level, such as the PEL).
- Results for the heavy equipment operators
and chipping equipment operators who were
sampled exceeded the silica PEL more frequently
than other workers evaluated.
- Workers with elevated silica exposures were
likely performing activities such as jack hammering
or sawing road surfaces and building materials,
moving and dumping dry concrete and brick rubble,
or crushing silica containing debris under
heavy equipment, generating silica containing
dusts.
- The silica sample results are important because
they represent airborne levels of respirable silica
dust, particles that are too small to see but
that can be breathed deeply and retained in
the lungs.
- Dust control methods, such as spraying water
or using vacuum equipment to suppress dust
generation, are particularly important for
protecting workers conducting dust-generating
activities on silica-containing materials (e.g.,
concrete, brick, mortar, grout, stone, sand,
and dried sludge containing sand).
- See detailed results of silica sampling.
Asbestos/Total
Fibers Results Summary
- Results indicate that many types of fibers
can be released during hurricane response and
recovery activities.
- Mixed fibers, including fiber glass, mineral
wool, man-made vitreous fibers, and synthetic
fibers, were present in 94 percent of the 235
samples analyzed for total fiber content.
- Overall, results obtained by OSHA showed
that individuals employed as heavy equipment operators,
laborers, waste/debris collectors, and quality assurance inspections had the
highest total fiber exposure levels. There
is not, however, a specific OSHA exposure standard
for total fibers.
- Although asbestos was found in less than
1 percent of the samples evaluated during this
phase of hurricane response and recovery, the
risk could be higher during later phases when
more workers are involved in building demolition.
- Individuals must wear an
appropriate respirator where asbestos or potential
asbestos containing materials may be present
and may be impacted by the operation until
the risk of asbestos exposure has been evaluated.
- Where asbestos is present, a specially trained competent
person, defined in 29 CFR 1926.1101,
can assist the employer in selecting the
controls (i.e., engineering controls, work
practices, and PPE) necessary to reduce exposures
and to protect workers.
- See detailed results of asbestos/total fiber sampling.
Gas and Vapor Results Summary
- Formaldehyde is a component of some building
materials, such as certain plywood, carpet
adhesive, and insulation sometimes used in
the manufacture of pre-fabricated trailers.
- Sampling results
for formaldehyde exceeded the action level
in nearly 20 percent of the 95 air samples
OSHA obtained during this phase of hurricane
response. Exposure levels for the individuals
evaluated approached, but did not exceed
OSHA's PEL.
- The available data suggests that the workers
most at risk of formaldehyde overexposure
were truck drivers and others responsible
for delivering and setting up prefabricated
trailers.
- Carbon monoxide is a colorless and odorless
gas released when gas flames, combustion engines,
and fires do not burn efficiently. Possible
sources of exposure include emergency power
generators used in poorly ventilated areas
and gas powered saws in need of service.
- Carbon monoxide levels exceeded the action
level in 17 percent of the 51 samples collected.
- On-site support workers (e.g., inspectors,
engineers) had the highest carbon monoxide
exposure levels among the workers evaluated.
- The available 399 results for 23 other gases
and vapors sampled were below the action level.
- See detailed results of gas and vapor sampling.
Metals Results Summary
- Exposure results indicate that the workers
evaluated during the operations characterized
during this phase of hurricane response and
recovery were rarely exposed to hazardous levels
of airborne metals (e.g., as metal dust or
fumes).
- These results represent
the sampled workers' exposure
to one or more of the 15 different metals analyzed,
including lead, zinc, copper, iron, nickel
and cadmium.
- OSHA evaluated workers in a wide range of
occupations, including heavy equipment operators,
structural steel workers, welders and cutters,
hazardous waste removal workers, and on-site
support personnel. Metal was detected in only
3 percent of the air samples.
- Only one of the 1,240 results for metals
exceeded the action level. That individual, exposed
to copper fume, was involved in debris reduction
activities. An exposure to copper fume could
result from hot work, such as cutting and welding.
- No metal was detected in most (97 percent)
of the air sample results that OSHA obtained.
- See detailed results of metal sampling.
Note: Cutting or burning on
painted metal surfaces must always be evaluated
for exposure to lead unless documentation
exists that precludes its presence.
Background
What these sampling results represent
This document summarizes
exposure results obtained by OSHA personnel between
mid-September and mid-December of 2005 in the region
impacted by hurricanes Katrina, Rita, and Wilma.
The area of impact included Texas, Louisiana, Mississippi,
Alabama, and Florida. Although the focus of both
the response and recovery effort and the exposure
data collection effort has been Mississippi and
Louisiana, all available results from Texas, Alabama
and Florida are also included in this summary.
Response and recovery operations occurred over
a large physical area and encompassed a wide range
of specific activities and operations. Exposure
data was collected for a limited subset of these
operations.
Operations conducted between September
and December 2005 included: utility restoration,
debris collection and reduction, tree trimming,
establishing temporary housing sites, demolishing
buildings, sand and sludge removal, repairing and
tarping roofs, community damage assessment, environmental
assessment and cleanup, and road and bridge repair.
During this time period, however, debris collection
and reduction activities were the primary operations
conducted and so they were also the activities most
frequently characterized in the exposure monitoring
data summarized here.
What these sampling results do not cover
Operations conducted during the initial response,
such as floodwater removal, and search and rescue
are not represented in the data summarized here.
Nor does this summary include operations that
had not begun as of mid-December 2005, such as
large-scale demolition of homes and structures,
including those built with asbestos-containing
materials.
How sampling was conducted
OSHA sampled a large number
of workers in a range of jobs to quickly identify
the most serious health threats during
response and recovery operations and to find
out what types of exposures typically occur during
these operations. In general, OSHA sampled the
substances that response and recovery workers were most likely to encounter
during the work they performed. The results of
these samples will help create an historic database
that can be used for future risk assessment.
Employers may use this information to evaluate
the level of hazard workers are likely to encounter
when working under similar conditions after future
hurricanes or related disasters.
OSHA collected air and noise samples to evaluate exposure
to air contaminants and noise during numerous
hurricane response and recovery activities. Except
for the gas and vapor samples, most of the results
summarized in this section were obtained using
personal sampling methods. To obtain personal
samples, individuals wore sampling devices during
the period evaluated to collect air samples from
their breathing zone or, in the case of noise
samples, from near their ears. In addition to
using personal sampling methods, some gas and
vapor samples were collected using area sampling
methods and using direct-reading instruments.
How samples were analyzed
Many types of air samples required laboratory
analysis and were sent to OSHA's Salt Lake
Technical Center laboratory, which is accredited
by the American Industrial Hygiene Association
(AIHA). The results of this analysis were recorded
as the average exposure level for the time period
that was sampled. Results for air samples obtained
with calibrated direct-reading instruments (e.g.,
carbon monoxide) were recorded as the average
exposure detected by the instrument during the
period sampled. Noise samples, which are also
obtained using direct reading instruments, were
reported the same way.
How results were evaluated
The
samples were collected during all or part of
the workers' work shifts and represent
their exposure during the period sampled. In
evaluating the results of these samples, OSHA
assumed that individuals experienced the same average
exposure during any additional unsampled portions
of their workshift. The results represent the
8-hour time-weighted-average (TWA) exposure
levels that the workers would have experienced
if they had continued the same tasks and used
the same methods throughout an 8-hour shift.
To determine whether an individual was overexposed
to a substance or noise, OSHA compared the sample
results to the:
- Permissible Exposure Limit (PEL). An worker
is considered overexposed if the sample result
exceeded the PEL for the hazard evaluated.
- Action Level (AL).
If not otherwise established by a standard,
the "action level" is
usually defined as half of an established occupational
exposure level. Although not overexposed, an
worker is considered at risk of being
overexposed if the result is between the AL
and the PEL. In this case the employer should
consider taking additional steps to ensure
the worker exposure levels do not reach the PEL.
Detailed Results
Summary of Noise Sampling Results
OSHA
measured noise exposure levels for workers performing
various hurricane response and recovery tasks involving
noisy activities or equipment. The 342 time-weighted
average (TWA) personal noise exposure levels obtained
by OSHA during this period indicate that many workers
are regularly exposed to hazardous levels of noise.
As shown in Table II-1, the noise exposure levels
for 20 percent of the 342 individuals sampled exceed
OSHA's PEL of 90 decibels on an A-weighted-scale
(dBA). Furthermore, when a subset of these workers
was evaluated using a lower (i.e., 80 dBA) threshold,
41 percent were found to have experienced TWA
noise levels of 85 dBA (the OSHA action level)
or higher.
This value of 85 dBA is important
because when exposure levels reach or exceed
an average level of 85 dBA as an 8-hour TWA,
workers should have employer-provided hearing
protection made available and be placed in a
hearing conservation program to minimize the
chance of noise-induced hearing loss. A hearing
conservation program should include noise exposure
monitoring, routine medical evaluations (hearing
tests), and training on noise and its effects.
General industry employers are required to take these steps when
exposures are at or above 85dBA.
| Table II-1:
Distribution of Personal Noise Dosimetry
Results for Hurricane Response and
Recovery Workers |
| |
Total
number of personal samples |
Number
of workers with noise exposure
in this range (percentage of total
number of results) |
| Workers Evaluated Against the
90dBA PEL |
|
90 dBA or less |
Over 90 dBA |
| All workers
evaluated |
342 |
274 (80%) |
68 (20%) |
| Workers Evaluated
Against the 85dBA General Industry Hearing
Conservation Level |
|
Less than 85
dBA |
85 dBA or greater |
| Workers evaluated
using methods for assessing hearing conservation
needs |
144 |
85 (59%) |
59 (41%) |
Notes:
Results summarize information posted to OSHA's
Hurricane Katrina, Rita and Wilma website
on December 16, 2005, without consideration
of sample duration and its effect on the
limits of detection.
dBA means decibels, measured on the A-weighted scale.
Results represent an 8-hour TWA value using a 5 dBA
doubling rate. Results that were obtained
over a period of less than 8 hours are extrapolated
assuming that the same level of exposure
continued for the full 8-hour shift.
Percentages may not add up to exactly 100 due to rounding.
Workers evaluated against the 90dBA PEL: Noise exposure
levels were obtained using either the method
for PEL comparison (90 dBA criteria, 90 dBA
minimum sampling threshold, 5 dBA doubling
rate) or the method for assessing hearing
conservation needs (85 dBA criteria, 80 dBA
minimum sampling threshold, 5 dBA doubling
rate).
Workers evaluated against
the 85dBA General Industry hearing conservation
level: Noise exposure levels were obtained
using only the method for assessing hearing
conservation needs (85 dBA criteria,
80 dBA minimum sampling threshold, 5
dBA doubling rate).
Results include only personal samples; area samples are not included. |
Analysis of the noise sampling results show
that the response and recovery workers most likely to be exposed to
hazardous levels of noise (over 90 dBA) include those involved in:
- Debris removal
- Debris reduction
- Site clearing
- Transportation restoration activities
In particular, those at greatest risk for overexposure
to noise include:
- Workers working with chippers, chain saws,
industrial vacuums, heavy equipment, or other
noisy machinery
- Laborers
- Waste/debris collectors
- Structural iron and steel workers
Sample results show that
individuals performing these jobs, as well as truck
drivers, flaggers/spotters, and others who spend
a significant amount of time in the immediate
vicinity of noisy operations, may be exposed
to noise levels above 90 dBA. Provide hearing
protection and training, and enroll workers in
a hearing conservation program. For general industry
employers, these actions are required when noise
exposures exceed 85dBA.
Workers are less likely
to experience hazardous noise exposure levels
if they do not operate noisy equipment themselves,
or if their jobs allow them to move away from
noisy equipment or to less noisy locations. The
available results suggest that some job categories,
such as utility workers and support personnel,
were less likely to expose the worker to hazardous
levels of noise for extended periods.
Users are cautioned, however that each work situation
is different. Regardless of an individual's
activities, if conditions are noisy enough
that workers separated by an arm's length
(approximately three feet) must raise their
voices to have a conversation, they are probably
exposed to 85 dBA or greater. If that level
of noise continues for most of the work shift,
the worker will likely be exposed to a level
of at least 85 dBA unless testing proves
otherwise.
Summary of Dust/Particulates Sampling Results
OSHA evaluated airborne
concentrations of dust (also called particulates)
in the breathing zone of 294 hurricane response
and recovery workers during this period. These
samples provided 217 results for total dust
and 77 results for the smaller respirable dust
particles (the respirable fraction). As shown
in Figure II-A and Table II-2:
- Analysis of the total dust samples indicate that six percent of the individuals sampled exceeded the PEL (15 milligrams per cubic meter (mg/m3), while another 10 percent were exposed
to concentrations above the action level (but below the PEL).
- The respirable dust
sample results indicate that 4 percent of
the individuals sampled exceeded the PEL (5 mg/m3),
while another 4 percent had exposures that
exceeded the action level.
The vast majority of the dust results that
exceeded either the action level or the PEL
were associated with:
- Debris collection/removal
- Debris reduction
- Site clearing/grading operations
However, not all jobs associated with this
work resulted in notable dust exposure. The
personal air sampling results for total and
respirable dust were below the action level
for the following occupation categories:
- Chain saw and sawing machine operators
- Welders
- Structural iron and steel workers
- Office personnel (e.g., administrators,
secretaries) and on-site support personnel
(e.g., engineers, inspectors, scientists,
technicians, estimators)
Under the conditions sampled, results were
below the action level even when these jobs
were associated with debris removal and reduction
or site clearing operations. In some cases,
workers might have been protected by dust control
methods such as standing upwind of dusty equipment,
or using wet methods or exhaust ventilation
for some tasks. For example, workers reduced
airborne dust at some debris sites by using
water spray to keep the roads and debris damp.
Other workers, such as steel erectors, office
personnel, and on-site support personnel might
have worked at a distance from the source of
the dust (or entered the dusty area only infrequently),
so their average dust exposure was below the
action level on the dates sampled. Finally,
the amount of rainfall preceding sampling would
directly impact the amount of ambient dust.
| Table
II-2: Distribution of Personal Air
Sampling Dust Results for Occupations
with at Least One Result Exceeding
the Action Level |
| |
Total
dust results, with PEL = 15 mg/m3 (percentage of total
number of results) |
Respirable
dust results, with PEL = 5 mg/m3 (percentage
of total number of results) |
| Occupation |
Number
of personal samples |
Less
than the action level |
From
the action level to the PEL |
Greater
than the PEL |
Number
of personal samples |
Less
than the action level |
From
the action level to the PEL |
Greater
than the PEL |
| All workers
evaluated |
217 |
183 (84%) |
21 (10%) |
13
(6%) |
77 |
71 (92%) |
3
(4%) |
3
(4%) |
| Heavy equipment
operators |
74 |
49 (66%) |
14 (19%) |
11 (15%) |
41 |
39 (93%) |
1
(2%) |
2
(5%) |
| Laborers |
35 |
29 (83%) |
5
(14%) |
1
(3%) |
17 |
16 (94%) |
1
(6%) |
1
(6%) |
| Spotters
and Flaggers |
23 |
22 (96%) |
0
(0%) |
1
(4%) |
7 |
7 (100%) |
0
(0%) |
0
(0%) |
| Waste and
debris collectors (including hazardous
waste) |
9 |
8 (89%) |
1 (11%) |
0
(0%) |
2 |
2 (100%) |
0
(0%) |
0
(0%) |
| Chippers |
1 |
0
(0%) |
1 (100%) |
0
(0%) |
2 |
1
(50%) |
1 (50%) |
0
(0%) |
Notes:
Results summarize information posted to OSHA's
Hurricane Katrina, Rita, and Wilma website
on December 16, 2005, without consideration
of sample duration and its effect on the
limits of detection.
Percentages may not add up to exactly 100 due to rounding.
Results that were obtained over a period of
less than 8 hours are extrapolated
assuming that the same level of exposure
continued for the full 8-hour shift.
The PELs for dusts are presented as a concentration
of dust in air, or milligrams of dust
per cubic meter of air (mg/m3 ). Sample
results for other occupations evaluated
were less than the action level.
This summary represents results of personal air
samples evaluating either total or
respirable dust. |
Summary of Silica Sampling Results
Response and recovery workers
may be exposed to crystalline silica (called
silica in this document) when they crush, grind,
chip, or cut concrete, stone, brick, tile, or mortar.
Individuals might also be exposed to this substance
if they handle materials that release very fine
silica particles (e.g., if they dump loads of materials
such as dry sludge and construction debris that
include dust from concrete or sand). In particular,
silica exposure can occur when heavy traffic disturbs
silica-containing road dust at hurricane debris
sites. Silica exposure is also common where workers
operate heavy equipment with open cabs (an enclosed
cab can separate the worker from the dust source),
or when workers do not use wet methods (such as
water mist spray) to suppress dust.
Figure II-B present information on hurricane response and
recovery worker exposure to silica. Overall the
PEL was exceeded in 11 percent of the samples
analyzed for silica. Another 9 percent of the results
were at or above the action level, but did not
exceed the PEL.
The percentage of workers exposed above the PEL
was higher in areas where samples confirmed that
airborne silica was present. Of the 276 personal
breathing zone samples analyzed, 83 (30 percent)
actually contained silica. However, among these
83 samples, results show that 30 percent of the
workers sampled exceeded the PEL, while another
34 percent had exposures exceeded the action level.
All but one of the samples at or above the action
level were associated with conducting debris
collection, reduction, or demolition activities.
The only exception was a sweeper working at a maritime
port restoration site. These results indicate that
dust control methods should be used more frequently
during debris collection, reduction, and demolition,
and other dusty tasks involving materials that
are suspected of containing silica.
Note about the silica PEL: OSHA's PEL for silica is calculated based on
the percentage of silica in a respirable
dust sample. Once the PEL has been calculated
for a specific sample, the respirable
dust concentration associated with that
sample can be compared to this PEL. To
calculate a silica PEL, OSHA uses the
following equation:
PEL = 10 mg/m3/([% silica in respirable
dust] + 2) |
As shown in Figure II-C and Table II-3, heavy
equipment operators and machine operators were
most likely to experience notable silica exposure.
Nearly two-thirds of machine operators sampled
were exposed at or above the action level. Nearly
one-quarter of heavy equipment operators sampled
were exposed above the action level. These operators
were likely performing activities such as jack
hammering or sawing building materials or road
surfaces, moving and dumping concrete and brick,
or crushing silica-containing debris under heavy
equipment that would produce silica-containing
dusts.
Sample results for several work groups consistently
indicated low concentrations of silica during this
phase of hurricane response and recovery. Job groups
for which all the available silica results were
less than 50 percent of the PEL include waste collectors,
truck drivers, and administrative personnel.
| Table
II-3: Distribution of Personal Air Sampling
Results for Crystalline Silica in Occupations
with at Least One Result Exceeding the
Action Level |
| |
Number
of Samples (percentage of total number
of results) |
| Occupation |
Total number of
personal samples |
Number of samples
where silica was detected |
Less than the action
level |
From the action
level to the PEL |
Greater than the
PEL |
| All workers evaluated |
276 |
83 |
222 (80%) |
25
(9%) |
29
(11%) |
| Heavy equipment operators |
144 |
51 |
109 (76%) |
16
(11%) |
19
(13%) |
| Laborers |
34 |
8 |
24
(71%) |
3
(9%) |
3
(9%) |
| Spotters and Flaggers |
33 |
4 |
30
(91%) |
2
(6%) |
1
(3%) |
| On-site support personnel
(e.g., engineers, inspectors, scientists,
technicians, estimators) |
25 |
6 |
24
(96%) |
0
(0%) |
1
(4%) |
| Machine operators (including
grinding, sawing machines) |
11 |
9 |
4
(40%) |
3
(20%) |
4
(40%) |
| Chipper operator |
6 |
1 |
5
(83%) |
0
(0%) |
1
(17%) |
| Sweeper |
2 |
1 |
1
(50%) |
1
(50%) |
0
(0%) |
Notes:
Results summarize information posted to OSHA's
Hurricane Katrina, Rita, and Wilma website
on December 16, 2005, without consideration
of sample duration and its effect on the limits
of detection.
Results that were obtained over a period
of less than 8 hours are extrapolated assuming
that the same level of exposure continued
for the full 8-hour shift.
Percentages may not add up to exactly
100 due to rounding.
See text box for information
on OSHA's PEL for silica.
Results include only personal samples; area samples are not included. |
Summary of Asbestos and Total Fiber Sampling Results
Asbestos
Response and recovery workers in numerous jobs were sampled to determine
their asbestos exposure levels. In particular,
OSHA evaluated workers in jobs related to debris
collection and reduction activities, such as heavy
equipment operators, truck drivers, hazardous materials
removal workers, and laborers. In all, OSHA obtained
221 personal air samples and 38 area samples (a
total of 259 samples). A measurable amount of asbestos
(also called a quantifiable level) was
found in only two of the 259 samples collected
and both of these results were less than one-tenth
of the PEL of 0.1 fiber per cubic centimeter of
air (f/cc). As shown in Figure II-D, this means
that asbestos was found in 1 percent of the samples.
The measurable amounts of asbestos were associated
with laborers performing site-clearing operations.
Although asbestos was not detected in air samples
from the breathing zone of most workers during
these first few months of hurricane response activity,
individuals might encounter asbestos more frequently
as demolition work increases in later phases of
hurricane recovery.
Note: There are over 45, 000 structures slated
for demolition in New Orleans. Approximately 90%
of these structures were built before 1980, increasing
the possibility that they contain Asbestos Containing
Building Materials.
Regardless of the phase of hurricane
response, employers need to take special steps
to protect workers involved in demolition of buildings
known to contain, or suspected of having asbestos
in some of the building materials. Workers must
also be protected when debris of those materials
are collected, removed, or processed for disposal.
Typical asbestos worker protection measures include:
- Evaluating work sites to determine whether asbestos
is in the building materials
- Using only workers that are trained and equipped
for handling asbestos
- Establishing restricted areas and erecting
enclosures (where feasible) to prevent asbestos
from spreading through the work area
- Wetting materials to keep fibers from becoming
airborne
- Selecting appropriate
personal protective equipment (PPE), including
respirators
- Avoiding dumping asbestos-containing materials
into dumpsters
A competent person,
who is specially trained in safe asbestos removal
and handling methods, can assist the employer in
selecting the controls (i.e., engineering controls,
work practices, and PPE) necessary to reduce exposures.
For additional information about asbestos at construction or demolition sites,
see OSHA's Asbestos Safety and Health Topics page.
OSHA's Asbestos Standard for construction is contained in 29 CFR 1926.1101.
Other Fibers
The analysis OSHA performed
for asbestos also showed that other types of fibers
were present in almost all the samples collected.
Mixed fibers in workplaces typically include fiberglass,
mineral wool, cellulose, man-made vitreous fibers,
and synthetic fibers from fabrics. The combined
result for asbestos and other fibers together is
called the total fiber level. Mixed fiber types
were detected in 222 of the 235 area and personal
samples analyzed for total fibers (a subset of
the samples analyzed for asbestos). As shown in
figure II-E, this mixed fiber was present in 94
percent of the samples. These results suggest that
fibers can become airborne during certain hurricane
recovery tasks, so worker protection is important
during jobs that involve handling fibrous materials
(fiberglass, asbestos, etc). In particular, workers
must wear an appropriate respirator until the risk
of asbestos exposure has been determined through
the identification of potential sources and through
airborne exposure sampling.
Among the samples reviewed
for this summary, the highest total fiber results
were associated with those employed as heavy
equipment operators, laborers, waste/debris collectors,
and quality assurance inspectors.
| Table
II-4: Summary Air Sampling Results for
Asbestos and Total Fibers |
| |
|
|
Number
of Samples
(percentage of
total number of results) |
| Fiber |
Total
number of samples |
Number
of samples with quantifiable results |
Less
than the action level |
From
the action level up to the PEL |
Greater
than the PEL |
| Asbestos |
259 |
2 |
259
(100%) |
0
(0%) |
0
(0%) |
| Total (mixed)
fiber |
235 |
222 |
N/A |
N/A |
N/A |
Notes:
Results summarize information posted to OSHA's
Hurricane Katrina, Rita, and Wilma website
on December 16, 2005, without consideration
of sample duration and its effect on the limits
of detection.
Results that were obtained over a period
of less than 8 hours are extrapolated assuming
that the same level of exposure continued
for the full 8-hour shift.
OSHA's PEL for Asbestos is 0.1 fibers per cubic
centimeter of air (f/cc). N/A means "not applicable" because
there is no PEL specifically for total fiber.
Results include both personal and area samples. |
Summary of Gas and Vapor Sampling Results
The available results for gas and vapor personal and
area sampling showed that, during this initial phase
of hurricane response and recovery, workers experienced
exposure to measurable levels of some substances;
however, their exposure to gases and vapors did not
exceed the respective PELs for the substances sampled.
OSHA obtained 545 air sample results for 25 different
individual substances or groups of substances (see
sidebar). Except for samples evaluating formaldehyde,
most results were obtained using direct reading instruments
and many represent area samples collected near the
source of the gas or vapor.
Table II-5 provides a summary of the gases and vapors for which samples
were collected and analyzed most frequently (i.e.,
more than 30 samples were collected for each). As
indicated in Figure II-F, exposure levels at or above
the action levels were found for formaldehyde and
carbon monoxide only. All results for other gases
or vapors were below the action level.
Formaldehyde is commonly used as a preservative
and is an ingredient in the binding agent used
to manufacture certain construction materials (e.g.,
some plywoods).
|
|
- 1,1,1,2-Tetrafluoroethane (8 results)
- Aliphatic organics (2 results)
- Ammonia (3 results)
- Aromatic organics (2 results)
- Benzene (47 results)
- Carbon dioxide (3 results)
- Carbon monoxide (51 results)
- Chlorine (2 results)
- Diazinon (3 results)
- Ethyl benzene (31 results)
- Formaldehyde (95 results)
- Glutaraldehyde (8 results)
- Hexone (10 results)
- Hydrocarbon (10 results)
- Hydrogen sulfide (10 results)
- Methane (6 results)
- Methylene bisphenyl isocyanate (2 results)
- Oxygen (10 results)
- Petroleum distillates (5 results)
- Petroleum hydrocarbons (7 results)
- Toluene (137 results)
- Toluene-2,4-diisocyanate (TDI) (4 results)
- Turpentine (3 results)
- Volatile organic (17 results)
- Xylene (36 results)
|
The individuals in the areas with the
highest formaldehyde exposure were truck drivers
and workers placing and constructing temporary
facilities, such as those delivering, inspecting,
and installing newly manufactured pre-fabricated
trailers that had been sealed (without air circulation)
during delivery. During these activities, employers
must conduct evaluations to determine if workers
are being exposed to formaldehyde at hazardous
concentrations. A variety of gas detection equipment
(e.g., air sampling media, hand-held instruments)
is commercially available for measuring
exposure to formaldehyde and can be used to identify
locations where workers could be overexposed.
| Table
II-5: Summary of Air Sampling Results for
Gases and Vapors for Which OSHA Obtained
at Least 30 Results |
| |
|
|
Number
of Samples (percentage of
total number of results) |
| Gas or
vapor |
Total
number of samples |
Number
of samples with quantifiable results |
Less
than the action level |
From
the action level up to the PEL |
Greater
than the PEL |
Applicable
exposure limits (as ppm) |
| Formaldehyde |
95 |
83 |
71* (75%) |
18** (19%) |
6*** (6%) |
PEL
0.75
AL 0.5
STEL 2.0 |
| Carbon monoxide |
51 |
15 |
48
(94%) |
3
(6%) |
0
(0%) |
PEL
50 |
| Toluene |
137 |
2 |
137
(100%) |
0
(0%) |
0
(0%) |
PEL
200
Ceiling 300 |
| Benzene |
47 |
2 |
47
(100%) |
0
(0%) |
0
(0%) |
PEL
1
AL 0.5 |
| Xylene |
36 |
0 |
36
(100%) |
0
(0%) |
0
(0%) |
PEL
100 |
| Ethyl Benzene |
31 |
0 |
31
(100%) |
0
(0%) |
0
(0%) |
PEL
100 |
Notes:
Results summarize information posted to OSHA's
Hurricane Katrina, Rita, and Wilma website
on December 16, 2005, without consideration
of sample duration and its effect on the limits
of detection.
Percentages may not add up to exactly
100 due to rounding.
Exposure limits are presented as parts
of contaminant per million parts of air
(ppm).
PEL means permissible exposure limit,
as an 8-hour time-weighted average (TWA).
Action level means OSHA's action
level for the substance; or, if not otherwise
established by a standard, the "action
level" is usually defined as half
of an established occupational exposure
level.
STEL means short-term exposure limit.
Ceiling level means the maximum exposure limit for a
substance, which worker exposure must never exceed—even for an instant. If
instantaneous monitoring is not feasible, then the ceiling level is measured as
a 15-minute TWA exposure that shall not be exceeded at any time during the working day.
* For formaldehyde, this category includes
results that are less than the action level
of 0.5 ppm or, if short term samples, less
than half the STEL of 2 ppm.
** For formaldehyde,
this category includes results that are
equal to or greater than OSHA's action
level of 0.5 ppm or, if short term samples,
half the STEL of 2 ppm.
*** For formaldehyde,
this category includes results that are
greater than the PEL, or for short term
samples, OSHA's STEL. Results that were obtained over a period
of less than 8 hours are extrapolated assuming
that the same level of exposure continued
for the full 8-hour shift.
Results include both personal and area
samples. |
Carbon monoxide is a gas that can cause death
within several minutes of exposure to high concentrations.
The gas is a natural byproduct of combustion and
is generated by gas flames, internal combustion
engines (such as gasoline powered generators or
motors), or fires. The hurricane response and recovery
workers in the areas with the highest carbon monoxide
exposure levels were on-site support workers conducting
building inspections. In these cases, the carbon
monoxide likely originated from generators, gas
powered saws, and other internal combustion engines.
Do not use this type of equipment in enclosed areas,
where the toxic gas can build up. Where the possibility
of carbon monoxide exposure exists, employers must
conduct evaluations to determine if workers are
being exposed to carbon monoxide at hazardous concentrations.
Hand-held direct-reading instruments for measuring
carbon monoxide are readily available from commercial sources.
Summary of Metal Sampling Results
The available exposure
results for metals indicate that the evaluated
workers rarely experienced significant
exposure to metals during this phase of
hurricane response and recovery activities.
Overall, OSHA recorded air sampling results
for 15 different metals (see sidebar).
Because most workers did not work with
a large number of different metals in a
day, OSHA focused primarily on the metals
associated with materials that the individual
handled.
However, the standard analytical
test methods used to measure certain metals
also test for the presence of other metals
at the same time. When tests provided results
for additional metals, those additional
results were included in this review. Altogether,
OSHA obtained 1,240 results representing workers exposures to airborne metals,
including metal fumes.
|
|
- Antimony (90 results)
- Arsenic (44 results)
- Beryllium (90 results)
- Copper (128 results)
- Cadmium (130 results)
- Chromium [metal and insoluble salts] (84 results)
- Cobalt (87 results)
- Iron oxide (88 results)
- Lead (136 results)
- Manganese (86 results)
- Molybdenum (87 results)
- Nickel (87 results)
- Silver (5 results)
- Tin (5 results)
- Zinc oxide (92 results)
|
OSHA evaluated metal exposure
for response and recovery workers in many occupations and performing
diverse activities including heavy equipment operators,
chipping equipment operators, structural iron and
steel workers, truck drivers, flaggers/spotters,
saw operators, welders and cutters, hazardous waste
removal workers, and on-site support personnel
(e.g., engineers, inspectors, scientists, technicians,
estimators). Only 3 percent (42) of the
results showed detectable levels of metals and
only one was more than the action level (see Figure
II-G). That result, 68 percent of the PEL for copper,
was associated with a laborer involved in debris
reduction activities. Examples of debris reduction
tasks that could generate airborne copper include
grinding actions, such as abrasive cutting
of copper objects, which generates copper dust,
or hot work (welding or cutting metal) with
a gas torch or electric arc equipment, which
can generate metal fume.
Table II-6 summarizes the air sampling results
for some metals commonly found in construction
materials.
Table
II-6: Summary Personal Air Sampling Results
for Metals
|
| |
|
|
Number
of Samples
(percentage of total number of results) |
| Metal |
Total
number of personal samples |
Number
of samples with quantifiable results |
Less
than the action level |
From
the action level up to the PEL |
Greater
than the PEL |
Exposure
limits (as mg/m3) |
| Cadmium |
130 |
0 |
130
(100%) |
0
(0%) |
0
(0%) |
PEL
= 0.005
AL = 0.0025 |
| Chromium (metal
and insoluble salt) |
84 |
0 |
84
(100%) |
0
(0%) |
0
(0%) |
PEL = 1 |
| Copper fume |
128 |
5 |
127
(99%) |
1
(1%) |
0
(0%) |
PEL = 0.1 |
| Iron oxide fume |
88 |
21 |
88
(100%) |
0
(0%) |
0
(0%) |
PEL = 10 |
| Lead (inorganic) |
136 |
0 |
136
(100%) |
0
(0%) |
0
(0%) |
PEL
= 0.05
AL = 0.03 |
| Zinc oxide fume |
92 |
3 |
92
(100%) |
0
(0%) |
0
(0%) |
PEL = 5 |
Notes:
Results summarize
information posted to OSHA's Hurricane
Katrina, Rita, and Wilma website on December
16, 2005, without consideration of sample
duration and its effect on the limits
of detection.
Percentages may not add up to exactly
100 due to rounding.
PEL means permissible exposure limit,
as an 8-hour time-weighted average (TWA).
AL means OSHA's
action level for the metal.
The exposure limits for metals are presented
here as concentrations of dust in air,
or milligrams of dust per cubic meter
of air (mg/m3).
The PELs for
cadmium, chromium and lead are often
also presented as micro grams per cubic
meter of air (μg/m3 ),
obtained by multiplying the mg/m3 value
by 1,000 (e.g., 0.005 mg/m3 x 1,000
= 5 μg/m3).
Results that were obtained over a period
of less than 8 hours are extrapolated assuming
that the same level of exposure continued
for the full 8-hour shift.
Results for all the other metals sampled
were below the action levels for those
metals.
Results include only personal samples; area samples are not included. |
|
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