Page 78 - Plant design and economics for chemical engineers

60 PLANT DESIGN AND ECONOMICS FOR CHEMICAL ENGINEERS

Safety Regulations
The expressed intent of the Occupational Safety and Health Act (OSI-IA)
originally enacted in 1970 is “to assure so far as possible every working man and
woman in the Nation safe and healthful working conditions and to preserve our
human resources. . . .” The act presently affects approximately 6 million work-
places and 70 million employees. Over 500 amendments to the Act have been
introduced since the original legislation. A recent printing of the OSHA
standards can be found in Title 29, Chapter XVII, Part 1910 of the Code of
Federal Regulations.
Two of the standards directly related to worker health and important in
design work are Toxic Hazardous Substances and Occupational Noise Exposure.
The first of these two concerns the normal release of toxic and carcinogenic
substances, carried via vapors, fumes, dust fibers, or other media. Compliance
with the Act requires the designer to make calculations of concentrations and
exposure time of plant personnel to toxic substances during normal operation of
a process or plant. These releases could emanate from various types of seals and
from control-valve packings or other similar sources. Normally, the designer can
meet the limits set for exposure to toxic substances by specifying special valves,
seals, vapor-recovery systems, and appropriate ventilation systems.
The list of materials declared hazardous is being updated at a rapid rate.
Acceptable material exposure times and concentrations, likewise, are undergo-
ing continuous revision. Thus, it is important that the Federal Register be
examined closely before beginning the detailed design of a project. A useful
publication, Chemical Regulation Reporter,? detailing these proposed and new
regulations is now available to the design engineer. This weekly information
service includes information concerning the Toxic Substances Control Act (a law
administered by EPA rather than OSHA).
The Occupational Noise Exposure standard requires a well-planned, timely
execution of steps to conform to the 90-dBA rule in the design stages of a
project. Since many cities have adopted EPA’s recommended noise-level crite-
ria, or have stringent regulations of their own, design-stage noise control must
also consider noise leaving the plant. It is a good idea, during plant design, to
prepare two noise specifications: one to define the designer’s own scope of work
and the other to set vendor noise-level requirements for various pieces of
equipment.
Other standards in the safety area that are most often citied by OSHA and
which must be considered in detailed designs are the. National Electric Code and
Machinery and Machinery Guarding. A cursory investigation by a designer of
these and other OSHA standards quickly points out several problems, particu-
larly in interpretation. The standards frequently do not allow for alternate

tChemical Regulation Reporter, Bureau of National Affairs, Inc., 1231 25th Street, NW, Washington
DC 20037.