JICOSH was closed in 2008. For further information, please contact JISHA.
|
|
|
|
Case No.5
Chemical burns to skin by contact with high-concentration
raw liquid phenol while taking countermeasures
against abnormal reactions in the synthesizing
reaction process for phenol |
Click Here |
[Circumstances of Incident]
This accident occurred in a phenol
resin
manufacturing plant, where the phenol
resin
synthesis process included: mixing
raw phenol
with acid in a reaction vessel; adding
formalin
while heating the raw material; and
adding
denaturant prior to completing the
reaction
process by steam heating. Phenol resin
is
then produced by dehydration.
A team consisting of a supervisor and
four
workers was scheduled to work from
11:00
in the evening to 8 o'clock the next
morning.
Trouble occurred during phenol reaction
process.
As temperatures in the reaction vessel
rose
to an excessive level due to operational
mistakes by workers, cooling operations
were
started. However, other mistakes in
the cooling
process resulted in foam resin (an
intermediate
product) adhering to pipes and a wide
range
of other equipment. Although the foam
resin
was removed, there was another serious
mistake
by the supervisor. When the supervisor
ordered
the cover of a check valve to be opened
for
cleaning at around 10:30 in the
morning,
dehydration liquid spouted from the
valve.
Four workers who were engaged in this
emergency
operation were injured when their skin
was
burned by the high-concentration phenol.
|
[Causes]
The direct causes of this accident
may be
attributed to the supervisor's erroneous
instructions to clean the check valve
instead
of cleaning a strainer contaminated
by foam
resin due to trouble during the phenol
resin
synthesis process. Dehydration liquid
containing
high-density phenol spouting from the
valve
injured four workers
Although the supervisor and four workers
knew about the presence of the check
valve,
but had no knowledge of its structure
and
functions. This is why they mistook
the valve
as the strainer.
Moreover, while workers were wearing
protective
masks and rubber gloves, their clothing
was
made of cotton rather than impermeable
protective
fabric. As a result, they sustained
injuries
on their necks, bodies, arms and legs.
The indirect causes of this accident
relate
to the following:
(1) An instruction book covering this
operation
indicated no clear instructions on
vacuum
adjustments, leading to rapid increases
in
the temperatures in the reaction vessel
due
to a worker's erroneous operations.
Thus
vacuum cooling is required to correct
the
situation.
(2) When proceeding with the vacuum
cooling,
workers mistakenly switched over to
"dehydration
piping" as they normally do during
the
resin transport process, thus requiring
the
cleaning of the strainer and other
equipment.
|
[Type of business] Inorganic/organic chemicals manufacturing
[Type of accident] Contact with hazardous substances, etc.
[Number of victims]Four injured (involving absence from work) |
|