# (b) Protective Clothing
In any operation where the worker may come into direct contact with liquid ethylene dichloride, protective clothing shall be worn. The clothing shall be both impervious and resistant to ethylene dichloride.
Gloves, boots, overshoes, and bib-type aprons that cover boot tops shall be provided when necessary. Impervious supplied-air hoods or suits shall be worn when entering confined spaces such as pits or tanks unless known to be safe.
In situations where heat stress is likely to occur, air-supplied suits shall be used. All protective clothing shall be well-aired and inspected for defects prior to reuse.  (1)
Samples shall be collected at least quarterly in accordance with Appendix I for the evaluation of the work environment with respect to the recommended limit.
(  In a few of these capsule formations, there was desquamated epithelium. The renal tubular epithelium was swollen, and the tubules and lumina had many damaged cells.
The straight portions of the epithelium were the most severely affected.
 The liver showed individual or small groups of transparent cells and degenerative nuclear changes. There was considerable swelling of the reticuloendothelium, leukocytic infiltration, and moderate fatty degeneration.
The course of illness of the second worker (the 39-year-old man), who also died, followed a similar pattern with conspicuous jaundice and anuria.   ----   Rats, guinea pigs, rabbits, and monkeys were exposed at 400 ppm ethylene dichloride 7 hours/day, 5 days/week for various periods. All female rats were killed by the 10th exposure and all males by the 40th exposure. All male guinea pigs were killed by the 10th exposure and all females by the 24th. One female and 2 male rabbits were exposed 165 times.      From these considerations it would appear that a more realistic appraisal of the TWA exposures of the majority of workers is 10-15 ppm.
Crystallization
Ethylene dichloride was found in the milk of nursing women occupa tionally exposed at approximately 15.5 ppm for an unspecified time.
The concentrations of ethylene dichloride in the milk ranged from 0.54 to 0.64 mg %. Concentrations of about 14.5 ppm ethylene dichloride were found in the women's breath.
Eighteen hours after exposure, the concentrations of ethylene dichloride in milk samples and breath were found to be 0.195-    Both male and female guinea pigs exposed at 100 ppm ethylene dichlo ride for as many as 162 7-hour exposures in 226 days had reduced growth rates and increased liver to body weight ratios compared to controls.
Lung, heart, kidney, spleen, and testes organ weight to body weight ratios were normal.
 Cats similarly exposed also had reduced growth rates.
A summary of findings from animal exposures is presented in Table XII-  A total of 30 breathing zone samples were taken in the center of the room and at points considered to have high concentrations of vapor. Twenty-five of the 30 measurements exceeded the maximum permissible concentration of 12.4 ppm (50 mg/cu m ) . The highest concentration of ethylene dichloride was found during its suction transfer from a carboy into the extractor.
During the 7-10 minutes required for this transfer operation, concentrations of 5.6 to 22.5 ppm (22.7-90.0 mg/cu m) were found. Ethylene dichloride vapor was also released during the discharge of brine into a sewer after it had been used for washing the ethylene dichloride extract.
Cetnarowicz  reported ethylene dichloride concentrations in a petroleum refinery which used an extraction solvent containing 80% ethylene dichloride and 20% benzene to separate and purify mineral oils from paraffins.
The concentrations determined at 4 locations within the refinery ranged from 10 to 200 ppm (0.04-0.8 mg/liter). The results of 2-3 samples collected at each site are presented in Table III-l.
The measured benzene concentrations ranged from 10-25 jug/liter. The sampling and analytical methods used in this study were not given.  In another study, Brzozowski Carbon disulfide was determined to be the best desorbent for ethylene dichloride collected in charcoal tubes.

# (c) Analysis
Several methods have been used to quantify ethylene dichloride in air samples.
The analytical methods can be divided into 2 broad categories:
( V.

# DEVELOPMENT OF STANDARD

# Basis for Previous Standards
The  in order to avoid confusion about the word ''allowable" in the MAC concept.
The TLV was maintained at 75 ppm until 1952. At that time, the ACGIH changed the TLV back to 100 ppm. Again, no information was given about the reasons for the change.
 The definition of TLV as a time-weighted average (TWA) was formulated in 1953 by the ACGIH.
The   Under these conditions, it should not be necessary to comply with all of the provisions of this recommended standard. However, concern for worker health requires that protective measures be instituted below the enforceable limit to ensure that exposures stay below that limit. Therefore, environmental monitoring and recordkeeping is recommended for those work situations which involve exposure above one-half the recommended limit, to delineate work areas that do not require the expenditure of health resources for control of inhalation hazards. One-half the environmental limit has been chosen on the basis of professional judgment rather than on quantitative data that delineate nonhazardous areas from areas in which a hazard definitely exists.

# VI. WORK PRACTICES
The principal method for manufacturing ethylene dichloride is by reacting chlorine with ethylene.  Other chlorinated ethanes may be co products of ethylene dichloride manufacture and caution must be taken to avoid exposure to these substances as well.

# EXTREME CAUTION MUST BE EXERCISED AT ALL TIMES WHEN USING CARBON DISULFIDE BECAUSE OF ITS HIGH TOXICITY AND FIRE AND EXPLOSION

# HAZARDS. IT CAN BE IGNITED BY HOT STEAM PIPES. ALL WORK WITH CARBON DISULFIDE MUST BE PERFORMED UNDER AN EXHAUST HOOD. (d) Typical chromatographic operating conditions:
(1) 50 ml/min (70 psig) helium carrier gas flow.
(2) 65 ml/min (24 psig) hydrogen gas flow to detector.
(3) 500 ml/min (50 psig) airflow to detector.