Chemical Engineering License Review, Second Edition
This text contains 146 problems with detailed step-by-step solutions, and is an ideal study guide and the first truly practical, no-nonsense review for the difficult PE Exam.
TABLE OF CONTENTS Chemical Engineering License Review, Second Edition
Chapter 16: Plant-Safety
The purpose of this chapter is to offer a guideline, not a rigid procedure, in the safety aspect of process engineering. The user must exercise his/her judgement as to the appropriateness of a proposed method and deviate if a comparatively safe design is achieved as a result of such deviation. Under any circumstance, however, safety must not be compromised with cost. Theoretical derivations of the formulas have been avoided to get to the point as quickly as possible.
Toxicology and Industrial Hygiene
The degree to which a substance is poisonous is termed its toxicity. A toxicant is any chemical substance which when inhaled, ingested, absorbed through the skin or when applied to, injected into or developed within the body, in relatively small amounts may cause, by its chemical reaction, damage to the body structure or disturbance to human function or even death. Most chemicals enter the body through eyes, respiratory tract, digestive tract and skin. Two levels of toxicity are defined: (1) acute "short term" exposure that causes initiation poisoning, (2) chronic-"long period" exposure that causes anemia, leukemia and death.
Threshold Limit Values (TLV) and Exposure Limits
Toxic threshold limit values (TLVs) are the greatest concentrations of a toxicant in air that can be tolerated for a given length of time without any toxic effects. Definitions of commonly used limit values are given below.
The different types of TLV's and exposure limits are as follows:
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TLV-TWA
The time weighted average for a normal eight-hour workday or 40 hour work week...
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