# INTRODUCTION
Furthermore, product substitution should be a paramount consideration wherever ethylene dichloride is identified or its presence suspected, and it should be replaced wherever feasible with less harmful substitutes.
The recommended standard would apply to the processing, manufacture, and use of ethylene dichloride and products containing ethylene dichloride.

# I. BASIS FOR A REVISED ETHYLENE DICHLORIDE STANDARD
No epidemiologic studies that were designed to investigate the carcinogenicity of ethylene dichloride in humans have been found in the literature.
The seven epidemiologic studies referenced in the criteria document refer to physiological alterations and morbidity (1).

# Studies at the National Cancer Institute have been completed on an animal bioassay of ethylene dichloride (EDC)
given by gastric intubation.
The results are summarized in Table I.
There is a statistically significant positive association between the dosage of ethylene dichloride and the incidence of squamous-cell carcinomas of the forestomach and hemangiosarcomas of the circulatory system in male rats. In female rats, there was a statistically significant increased incidence of adenocarcinomas of the mammary gland.
Ethylene dichloride was carcinogenic in mice also, causing mammary adenocarcinomas and endometrial tumors in female mice, as well as producing lung adenomas in mice of both sexes.
There was a doseresponse relationship for total tumors in both mice and rats, as well as a dose-response relationship for most specific types of tumors.  (2) Comprehensive physical examination.
( (5) Emergency telephone numbers shall be prominently posted.

# (b) Engineering Controls
Engineering controls shall be used to limit the inhalation of, and to minimize skin contact with, ethylene dichloride by controlling the amount of ethylene dichloride that is emitted into the air. The most effective control measure is enclosure of unit operations and processes. (1) Access to the regulated area shall be limited to employees having assigned duties there.
(2) A daily entry roster shall be kept of all employees entering the regulated area and of their length of stay.
(3) Employees working in regulated areas shall wash their face, neck, hands, and forearms each time they leave the regulated area. Washing facilities shall be provided at each exit. Employees working in regulated areas shall wash their hands and forearms before using the toilet.
(4) Employees engaged in operations in which ethylene dichloride is transferred, charged, or discharged, or which involve using a laboratory-type hood, opening a closed system, or repackaging, shall be provided with gloves and aprons or coveralls or with fullbody protective suits resistant to penetration by ethylene dichloride.
(5) As a backup precaution, employees using glove boxes to handle ethylene dichloride shall wash their hands and arms on completion of the assigned task.
(6) When employees use protective clothing and equipment, they shall remove it and leave it at the exit before they leave the regulated area; the employees shall then wash their hands, forearms, face, and neck to remove accumulated ethylene dichloride before they enter nonregulated areas.

# (d) Clean Work Clothing Room
A clean work clothing room shall be established and maintained that is free of ethylene dichloride contamination and that contains locker facilities.
(1) Shower facilities shall separate the clean work clothing room from the regulated area.
(2) The clean work clothing room shall be kept under positive pressure relative to the regulated area.
(  and that prescribed procedures will be followed.
(1) All lines shall be disconnected or blocked while a vessel is being cleaned. All valves or pumps leading to and from the vessel shall be closed down.
(2) The vessel shall have all liquid ethylene dichloride removed and be purged completely with air.
( (1) A program of personal monitoring shall be instituted to identify and measure, or permit calculation of, the exposure of each employee. Source and area monitoring may be used to supplement personal monitoring.
(2) In all personal monitoring, samples representative of exposure in the breathing zone of the employee shall be collected.
(3) For each ethylene dichloride determination, a sufficient number of samples shall be taken to characterize the employee's work and production schedules, location, or duties. Changes in production schedules shall be considered in deciding when samples are to be collected.
(4) Each operation in each regulated area shall be sampled at least once every 6 months while ethylene dichloride is produced or handled. For intermittent operations, ie, those lasting less than 6 months, at least one monitoring regimen shall be conducted during each operation period, and monitoring should coincide with the periods of maximum potential exposure to ethylene dichloride.
If an employee is found to be exposed to ethylene dichloride at concentrations exceeding the recommended occupational exposure limit, the exposure of that employee shall be measured at least once every

# D E P A R T M E N T O F H E A L T H , E D U C A T IO N , A N D W E L F A R E P U B L IC H E A L T H S E R V IC E C E N T E R FO R D IS E A S E C O N T R O L N A T I O N A L IN S T IT U T E FO R O C C U P A T I O N A L S A F E T Y A N D H E A L T H R O B E R T A T A F T L