California Code of Regulations › Title 8 - Industrial Relations › Division 1 - Department of Industrial Relations › Chapter 4 - Division of Industrial Safety › Subchapter 7 - General Industry Safety Orders › Group 16 - Control of Hazardous Substances › Article 110 - Regulated Carcinogens › Appendix C - Medical Surveillance Guidelines for Acrlonitrile

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
I. Route of Entry
Inhalation; skin absorption; ingestion.
II. Toxicology
Acrylonitrile vapor is an asphyxiant due to its
						  inhibitory action on metabolic enzyme systems. Animals exposed to 75 or 100 ppm
						  for 7 hours have shown signs of anoxia; in some animals which died at the
						  higher level, cyanomethemoglobin was found in the blood. Two human fatalities
						  from accidental poisoning have been reported; one was caused by inhalation of
						  an unknown concentration of the vapor, and the other was thought to be caused
						  by skin absorption or inhalation. Most cases of intoxication from industrial
						  exposure have been mild, with rapid onset of eye irritation, headache,
						  sneezing, and nausea. Weakness, light-headedness, and vomiting may also occur.
						  Exposure to high concentrations may produce profound weakness, asphyxia, and
						  death. The vapor is a severe eye irritant. Prolonged skin contact with the
						  liquid may result in absorption with systemic effects, and in the formation of
						  large blisters after a latent period of several hours. Although there is
						  usually little or no pain or inflammation, the affected skin resembles a
						  second-degree thermal burn. Solutions spilled on exposed skin, or on areas
						  covered only by a light layer of clothing, evaporate rapidly, leaving no
						  irritation, or, at the most, mild transient redness. Repeated spills on exposed
						  skin may result in dermatitis due to solvent effects.
Results after one year of a planned two-year animal
						  study on the effects of exposure to acrylonitrile have indicated that rats
						  ingesting as little as 35 ppm in their drinking water develop tumors of the
						  central nervous system. The interim results of this study have been supported
						  by a similar study being conducted by the same laboratory, involving exposure
						  of rats by inhalation of acrylonitrile vapor, which has shown similar types of
						  tumors in animals exposed to 80 ppm.
In addition, the preliminary results of an
						  epidemiological study being performed by duPont on a cohort of workers in their
						  Camden, South Carolina, acrylic fiber plant indicate a statistically
						  significant increase in the incidence of colon and lung cancer among employees
						  exposed to acrylonitrile.
III. Signs And Symptoms of Acute Overexposure
Asphyxia and death can occur from exposure to high
						  concentrations of acrylonitrile. Symptoms of overexposure include eye
						  irritation, headache, sneezing, nausea and vomiting, weakness, and
						  light-headedness. Prolonged skin contact can cause blisters on the skin, with
						  the appearance of a second degree thermal burn, but with little or no pain.
						  Repeated skin contact may produce scaling dermatitis.
IV. Treatment of Acute Overexposure
Remove employee from exposure. Immediately flush eyes
						  with water and wash skin with soap or mild detergent and water. If AN has been
						  swallowed and person is conscious, give large quantities of water immediately,
						  and induce vomiting. Give artificial resuscitation if indicated. More severe
						  cases, such as those associated with loss of consciousness, may be treated by
						  the intravenous administration of sodium nitrate, followed by sodium
						  thiosulfate, although this is not as effective for acrylonitrile poisoning a
						  for inorganic cyanide poisoning.
V. Surveillance and Preventive Considerations
A. Exposure to acrylonitrile has been linked to
						  increased incidence of cancers of the colon and lung in employees of the duPont
						  acrylic fiber plant in Camden, S.C. In addition, the animal testing of
						  acrylonitrile has resulted in the development of cancers of the central nervous
						  system in rats exposed by either inhalation or ingestion. The physician should
						  be aware of the findings of these studies in evaluating the health of employees
						  exposed to acrylonitrile.
Most reported acute effects of occupational exposure to
						  acrylonitrile are due to its ability to cause tissue annoxia and asphyxia. The
						  effects are similar to those caused by hydrogen cyanide. Liquid acrylonitrile
						  can be absorbed through the skin upon prolonged contact. The liquid readily
						  penetrates leather, and will produce burns of the feet if footwear contaminated
						  with acrylonitrile is not removed.
It is important for the physician to become familiar
						  with the operating conditions in which exposure to acrylonitrile may occur.
						  Those employees with skin diseases may not tolerate the wearing of whatever
						  protective clothing may be necessary to protect them from exposure. In
						  addition, those with chronic respiratory disease may not tolerate the wearing
						  of negative-pressure respirators.
B. Surveillance and screening. Medical histories and
						  laboratory examinations are required for each employee subject to exposure to
						  acrylonitrile above the action level. The employer must screen employees for
						  history of certain medical conditions which might place the employee at
						  increased risk from exposure to acrylonitrile.
1. Central nervous system dysfunction. Acute effects of
						  exposure to acrylonitrile generally involve the central nervous system.
						  Symptoms of acrylonitrile exposure include headache, nausea, dizziness, and
						  general weakness. The animal studies cited above suggested possible
						  carcinogenic effects of acrylonitrile on the central nervous system, since rats
						  exposed by either inhalation or ingestion have developed similar CNS
						  tumors.
2. Respiratory disease. The duPont data indicate an
						  increased risk of lung cancer among employees exposed to acrylonitrile.
3. Gastrointestinal disease. The duPont data indicate
						  an increased risk of cancer of the colon among employees exposed to
						  acrylonitrile. In addition, the animal studies show possible tumorogenic
						  effects on the stomachs of the rats in the ingestion study.
4. Skin disease. Acrylonitrile can cause skin burns
						  when prolonged skin contact with the liquid occurs. In addition, repeated skin
						  contact with the liquid can cause dermatitis.
5. General. The purpose of the medical procedures
						  outlined in the standard is to establish a baseline for future health
						  monitoring. Persons unusually susceptible to the effects of anoxia or those
						  with anemia would be expected to be at increased risk. In addition to emphasis
						  on the CNS, respiratory and gastrointestinal systems, the cardiovascular
						  system, liver and kidney function should also be stressed.