Occupational Fatalities Associated with Exposure to Epoxy
Resin Paint in an Underground Tank -- Makati, Republic of the
Philippines
On October 31, 1988, three men who were plugging leaks in and
waterproofing an underground water tank at a building in Salcedo
Village, Makati, Republic of the Philippines, were overcome by
paint fumes and died in the tank. The incident was investigated
by the Philippines Department of Health Field Epidemiology
Training Program.
The underground water storage tank measured 20 meters (66 feet)
long by 6 meters (19.8 feet) wide by 3 meters (9.9 feet) high and
was divided into three communicating compartments; entry and exit
were through one access hole. Because of typhoon rains on the
evening of October 30, the tank contained approximately 60
centimeters (2 feet) of water when the five-person crew began
work at 8 a.m., although company procedures required that such
tanks be dry before any waterproofing materials were applied. By
9 p.m., when the crew started to apply an epoxeal waterproofing
paint, the water was 10.2 centimeters (4 inches) deep. Two
60-centimeter (2-foot) diameter electrically powered exhaust fans
were provided to ventilate the tank, but the workers did not use
them because of concern for a possible electrocution hazard from
the standing water. At approximately 10 p.m., one worker left the
tank because he had become drowsy and nauseated and was vomiting.
At 10:30 p.m., a second worker left the tank to obtain coffee.
When these two workers returned to the tank at approximately
11:30 p.m., they found the three other crewmembers dead.
Autopsy reports attributed the cause of death to asphyxia. A
toxicology report from the Philippines National Bureau of
Investigation indicated that blood specimens from the three men
who died were negative for alcohol, sulfur, cyanide, and
phosphorus. Analysis of samples of the paint by the Philippines
Department of Science and Technology confirmed the presence of an
epoxy resin.
Reported by: RR Gavino, MD, ES Salva, MD, SP Gregorio, MD, NB
Bautista, MD, MM Dayrit, MD, Field Epidemiology Training Program,
CN Reodica, MD, National Capital Region, Philippines Dept of
Health; E Luis, MD, V Diaz, MD, Dept of Science and Technology; B
Vitasa, MD, Coll of Public Health, Univ of the Philippines; R
Garcia, MD, Philippines National Bureau of Investigation. Global
EIS Program, Div of Field Svcs, Epidemiology Program Office; Div
of Safety Research, National Institute for Occupational Safety
and Health, CDC.
Editorial Note
Editorial Note: Epoxy-based waterproofing paints contain several
types of toxic chemicals, and precautionary measures are required
when these paints are used in a confined space. Constituents of
epoxy resins will displace oxygen in a confined space and may
have an independent narcotic effect on exposed workers. In this
episode, the epoxy paint contained glycidyl ether, a reactive
dilutent used to decrease viscosity (1). Uncured glycidyl ether
vapors are more dense than air and will settle to the bottom of a
confined space, such as the water storage tank, thereby
displacing oxygen. For this reason, in the United States, CDC's
National Institute for Occupational Safety and Health (NIOSH)
recommends use of appropriate personal protective equipment
(i.e., a positive pressure-supplied air respirator and clothing)
and adequate ventilation when persons work with (or assess the
presence of) glycidyl ether in confined spaces.
In the United States, acute traumatic occupational deaths are
monitored by NIOSH through the National Traumatic Occupational
Fatalities (NTOF) data file (2). The NTOF data file uses death
certificates as the source of information for work-related
fatalities resulting from external causes of injury and poisoning
(International Classification of Diseases, Ninth Revision
(ICD-9), rubrics E800-E899). From 1980 through 1985, the NTOF
data file included 286 deaths (an average of 48 work-related
deaths per year) that involved workers in confined spaces with
cause of death directly attributable to asphyxiation, explosion,
or drowning. This figure probably underestimates the number of
such confined-space-related fatalities in the United States
because of misclassification and the lack of a specific ICD-9
code for "confined spaces" on the death certificate.
NIOSH defines a confined space as one that "by design has limited
openings for entry and exit, unfavorable natural ventilation
which could contain or produce dangerous air contaminants, and
which is not intended for continuous employee occupancy" (3). The
water storage tank in the incident reported here not only met
these criteria, but also contained dangerous air contaminants
introduced by the workers through the use of epoxeal
waterproofing paint.
Companies, municipalities, and other organizations who assign
workers to perform tasks within confined spaces should develop
and implement a comprehensive program for working in confined
spaces (3,4). Important considerations for such recommendations
are whether 1) entry is necessary or the assigned task can be
completed from the outside; 2) a confined space safe entry permit
has been issued by the company; 3) warning signs are posted where
they will be noticed by employees; 4) air quality in the confined
space has been tested for safety according to basic criteria*; 5)
employees and supervisors have been trained in the proper
selection and use of appropriate respiratory protection (6,7),
protective clothing, lifelines, and emergency rescue equipment;
6) employees have been trained to work in confined spaces and in
confined space rescue procedures; and 7) ventilation equipment is
available and/or used and air quality is tested when the
ventilation system is operating.
In addition, confined space procedures for work performed inside
tanks should specifically incorporate use of explosion-proof
lighting and fixtures in and near flammable atmospheres** and use
of nonflammable paints (when possible) for coating the interior
of tanks.
References
NIOSH. Criteria for a recommended standard...occupational
exposure to glycidyl ethers. Cincinnati, Ohio: US Department of
Health, Education, and Welfare, Public Health Service, CDC, 1978;
DHEW publication no. (NIOSH)78-166.
NIOSH. National traumatic occupational fatalities: 1980-85.
Morgantown, West Virginia: US Department of Health and Human
Services, Public Health Service, CDC, 1990.
NIOSH. Criteria for a recommended standard...working in
confined spaces. Cincinnati, Ohio: US Department of Health,
Education, and Welfare, Public Health Service, CDC, 1979; DHEW
publication no. (NIOSH)80-106.
NIOSH. A guide to safety in...confined spaces. Morgantown,
West Virginia: US Department of Health and Human Services, Public
Health Service, CDC, 1987; DHHS publication no. (NIOSH)87-113.
Office of the Federal Register. Code of federal regulations:
labor. Subpart Z, revised as of July 1, 1989. Washington, DC:
Office of the Federal Register, National Archives and Records
Administration, 1989. (29 CFR Section 1910.1000).
NIOSH. NIOSH respirator decision logic. Morgantown, West
Virginia: US Department of Health and Human Services, Public
Health Service, CDC, 1987; DHHS publication no. (NIOSH)87-108.
NIOSH. Guide to industrial respiratory protection. Morgantown,
West Virginia: US Department of Health and Human Services, Public
Health Service, 1987; DHHS publication no. (NIOSH)87-166.
National Fire Protection Association. The national electric
code handbook: the national electric code 1990. Quincy,
Massachusetts: National Fire Protection Association, 1989.
(Article nos. 501-9(a)(1) and 501-9(b)(1)).
National Fire Protection Association. Standard for spray
application using flammable and combustible materials. Quincy,
Massachusetts: National Fire Protection Association, 1989. (NFPA
standard no. 33.)
Oxygen concentration, greater than or equal to 19.5%;
concentration of flammable substances, less than 10% of their
respective lower explosive limits (i.e., the lowest concentration
at which explosive combustion can occur); and toxic air
contaminants, less than the concentration levels referenced in 29
CFR Section 1910.1000, subpart Z (5).
** Required by the National Electric Code Articles 501-9(a)(1)
and 501-9(b)(1) (8) and the National Fire Protection Association
Standard 33 (9).
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