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Engineering Control of Hazards
(See NFPA No. 30)
Regulations
The design, installation and operation of epichlorohydrin facilities should
comply with the federal rules and regulations of Title 29, Chapter XVII,
Part 1910, "Occupational Safety and Health Standards." These regulations
make mandatory the provisions of the standards promulgated by the American
National Standards Institute (ANSI) and the National Fire Protection
Association (NFPA). Part 1910 also requires compliance with Title 29,
Chapter XVII, Part 1926, "Safety and Health Regulations for Construction,"
and with the Walsh-Healy Act, Title 41-CFR, Chapter 50, Part 50-204. The
facilities also should comply with any state or local regulations if they
are more stringent than those mentioned above. The data and
recommendations contained in this bulletin are more specific in nature and
pertain primarily to epichlorohydrin.
Building Design
Equipment and vessels containing epichlorohydrin preferably should be
isolated from other facilities by walls and floors of fire resistive
construction.
At least two means of exit should be provided from each separate room or
building in which epichlorohydrin is stored, handled, or used. No portions
of such a room or building should be farther than 75 feet from the nearest
exit. Additional exits should be provided depending upon the number of
persons in the building. All exit doors should open out in the direction
of travel and should be provided with panic hardware. Fire doors should
open in the direction of travel and be of an approved type. (See NFPA
Standard No. 101, Life Safety Code.)
Operations where large quantities of epichlorohydrin are used should
preferably be open or housed in well-ventilated one story buildings.
Buildings containing packaged epichlorohydrin must be designed so that
vapors cannot concentrate and form flammable mixtures. Adequate low level
exhaust ventilation should be provided to remove these vapors in the event
that leakage does occur.
Provisions should be made for adequate spacing of chemical storage
buildings from other buildings and processing equipment.
Circumstances of use and the accident potential may require segregation of
floor drains from sanitary or process sewer systems.
Equipment Design
The technical problems of designing equipment, providing adequate ventilation, and formulating operating procedures which ensure maximum security and economy should be handled by experienced engineers and safety and fire protection specialists.
Relief valve discharges and intentional vapor releases should be collected for recovery or disposed of by burning if concentrations would subject personnel to exposure exceeding established limits.
For equipment handling liquid epichlorohydrin (inside a confined area), safety shields should be considered for stuffing boxes and mechanical seals. Caution should be exercised to ensure that the shield does not mask leaks and corrosion and provide a false sense of security.
Losses from the equipment to the work environment must be avoided or at least limited to the time weighted established limits. Personnel monitoring is recommended to assure such control.
The possibility of inadvertent mixing of epichlorohydrin with other chemicals in piping system merits extreme emphasis; the design of piping systems carrying ECH must address and avoid this possibility.
System Types
Totally Enclosed Systems
Totally enclosed systems are recommended for processes using epichlorohydrin as a raw material. The opening of equipment during
operation for adding or removing materials should be avoided to prevent
escape of epichlorohydrin.
Commercial combustible gas indicators are useful for periodic inspections
and for the location of small leak sources.
Partially Enclosed Systems
Processes where solid materials are in contact with epichlorohydrin should be totally enclosed, but it may be necessary on occasion to open the equipment, epichlorohydrin vapors can be removed from residual materials. Eye and skin contact and inhalation of vapors must be avoided in cleaning equipment and materials and handling these residues.
Personnel should not enter equipment unless proper precautions are taken to ensure that conditions are safe for entry. This may include measures such as purging with air and checking for the presence or level of ECH by detector tubes.
For enclosed systems that are continuously or periodically pressured with inert gas from a central supply, positive means of preventing backup of flammable, corrosive, or toxic materials into supply system should be furnished.
Equipment that is periodically filled with epichlorohydrin should be vented thru a scrubbing system and then to the outside atmosphere. Vents may be protected with flame arresters approved for this material. However, flame arresters are subject to plugging, particularly from corrosive epichlorohydrin vapors in contact with damp air. If used they should be so located that they can be frequently inspected and maintained. Vented epichlorohydrin should not enter the atmosphere where people will be exposed.
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