Chemistry Reference
In-Depth Information
should be made to appreciate the delayed effects following potentially lethal ex-
posures to phosgene.
Requirements for safety and environmental protection in industrial processing
using phosgene supplied on demand of the consumer by the implementation of
'dynamic' reactors for its production have been reported (see Section 2.1.2). The
manufacture and delivery of phosgene to the users on demand, without interme-
diate storage, has made it possible to strongly reduce the quantities of phosgene
contained within the plant. Confinement of the phosgene production, supply, and
utilization equipment in a double envelope makes it possible to collect any leakage
with ultimate destruction of the phosgene in specific installations [12, 13].
The following safety measures have been described for phosgene storage and
handling in a plant environment [1].
.
Phosgene storage and handling operations should be in a remote location from
the rest of the plant.
.
Phosgene storage rooms should be provided with an inspection window to per-
mit viewing of the area without the need of entry.
.
Ventilation switches and emergency protection equipment should be located
outside the storage area in easily accessible locations, which would be uncon-
taminated in the event of an emergency.
.
Where possible, phosgene should be generated on demand to avoid cylinder
handling and phosgene storage.
.
Phosgene gas should be used in preference to the liquid material.
.
The phosgene storage area should be continuously vented to alkali scrubbers.
.
A system of automatic analyzers should be employed to continuously monitor
the ambient air and all phases of the operation.
.
Alarms (audible, visual, and valve-closing) should be set to operate automatically
when the concentration of phosgene reaches the sensored limit.
.
Phosgene should be piped through a double-skinned conduit, such as a pipe
within a pipe. The outer pipe should be continuously monitored for phosgene.
Pipes containing phosgene should be distinctively marked.
.
Where phosgene is stored in tanks, these should be of a double-shell construc-
tion. Bulk phosgene is preferably stored underground.
.
Plant hardware that is exposed to phosgene should be composed of high quality
stainless steel, or PTFE, as appropriate.
.
An extensive preventative maintenance program should be operated to safeguard
against leaks and equipment failure. Potential emission sources should be iden-
tified.
.
An extensive training program should be implemented and a 'Phosgene Manual'
should be available.
.
Dosimeter badges should be worn by personnel who work in the phosgene area.
.
An emergency/evacuation plan should be established and frequent drills exe-
cuted.
.
Before equipment is taken out of service, all lines must be purged of any phos-
gene.
