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 B - Substance Technical Guidelines for Acrylonitrile

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
I. Physical and Chemical Data
A. Substance Identification:
1. Synonyms: AN; VCN; vinyl cyanide; acrylic nitrile;
						  cyanoethylene; Acrylon; Carbacryl; Fumigrain; Ventox; propenenitrile.
2. Formula: CH2 = CHCN
3. Molcular Weight: 53.1.
B. Physician Data:
1. Boiling Point (760 mm Hg): 77.3° C (171°
						  F)
2. Specific Gravity (water = 1): 0.81 (at 20° C or
						  68° F)
3. Vapor Density (air = 1) at boiling point of
						  acrylonitrile: 1.83.
4. Melting Point: -83° F (-117° F)
5. Vapor Pressure at 20° C (68° F): 83 mm
						  Hg.
6. Solubility in Water: Percent by weight at 20° C
						  (68° F): 7.35.
7. Evaporation Rate (Butyl Acetate = 1): 4.54.
8. Appearance and Odor: Colorless to pale yellow liquid
						  with a pungent odor at concentrations above the permissible exposure level. Any
						  detectable odor of acrylonitrile may indicate overexposure.
II. Fire, Explosion, and Reactivity Hazard Data
A. Fire:
1. Flash Point: -1° C (30° F) (open cup)
2. Autoignition Temperature: 481° C (898°
						  F).
3. Flammable Limits in Air, Percent by Volume: Lower:
						  3; Upper: 17.
4. Extinguishing Media: Alcohol foam, carbon dioxide,
						  dry chemical.
5. Special Fire-fighting Procedures: Do not use a solid
						  stream of water, since the stream will scatter and spread the fire. Use water
						  spray to cool containers exposed to a fire.
6. Fire and Explosion Hazards: Acrylonitrile is a
						  flammable liquid. Its vapors can easily form explosive mixtures with air. All
						  ignition sources must be controlled where acrylonitrile is handled, used, or
						  stored in a manner that could create a potential fire or explosion hazard.
						  Acrylonitrile vapors are heavier than air and may travel along the ground and
						  be ignited by open flames or sparks at locations remote from the site at which
						  acrylonitrile is being handled.
7. For purposes of compliance with the requirements of
						  Articles 141 through 148 of the General Industry Safety Orders, acrylonitrile
						  is classified as a Class 1B flammable liquid. For example, 7500 ppm,
						  approximately one-fourth of the lower flammable limit, would be considered to
						  pose a potential fire and explosion hazard.
8. For purposes of compliance with the regulations for
						  fire protection, acrylonitrile is classified as a Class B fire hazard.
9. For purpose of compliance with the Electrical Safety
						  Orders (California Administrative Code, Chapter 4, Subchapters 5 and 6)
						  locations classified as hazardous due to the presence of acrylonitrile shall be
						  Class I Group D.
B. Reactivity.
1. Conditions Contributing to Instability:
						  Acrylonitrile will polymerize when hot, and the additional heat liberated by
						  the polymerization may cause containers to explode. Pure AN may self-polymerize
						  with a rapid build-up of pressure resulting in an explosive hazard. Inhibitors
						  are added to the commercial product to prevent self-polymerization.
2. Incompatibilities: Contact with strong oxidizers
						  (especially bromine) and strong bases may cause fires and explosions. Contact
						  with copper, copper alloys, ammonia, and amines may start serious
						  decomposition.
3. Hazardous Decomposition Products: Toxic gases and
						  vapors (such as hydrogen cyanide, oxides of nitrogen, and carbon monoxide) may
						  be released in a fire involving acrylonitrile and certain polymers made from
						  acrylonitrile.
4. Special Precautions: Liquid acrylonitrile will
						  attack some forms of plastics, rubbers, and coatings.
III. Spill, Leak, and Disposal Procedures
A. If acrylonitrile is spilled or leaked, the following
						  steps should be taken:
1. Remove all ignition sources.
2. The area should be evacuated at once and reentered
						  only after the area has been thoroughly ventilated and washed down with
						  water.
3. If liquid acrylonitrile or polymer intermediate,
						  collect for reclamation or absorb in paper, vermiculite, dry sand, earth, or
						  similar material, or wash down with water into process sewer system.
B. Persons not wearing protective equipment should be
						  restricted from areas of spills or leaks until cleanup has been
						  completed.
C. Waste Disposal Methods: Waste material shall be
						  disposed of in a manner that is not hazardous to employees or to the general
						  population. Spills of acrylonitrile and flushing of such spills shall be
						  channeled for appropriate treatment or collection for disposal. They shall not
						  be channeled directly into the sanitary sewer system. In selecting the method
						  of waste disposal, applicable local, state, and federal regulations should be
						  consulted.
IV. Monitoring and Measurement Procedures
A. Exposure Above the Permissible Exposure
						  Limit:
1. Eight-hour Exposure Evaluation: Measurements taken
						  for the purpose of determining employee exposure under this section are best
						  taken so that the average eight-hour exposure may be determined from a single
						  8-hour sample or two (2) 4-hour samples. Air samples should be taken in the
						  employee's breathing zone (air that would most nearly represent that inhaled by
						  the employee).
2. Ceiling Evaluation: Measurements taken for the
						  purpose of determining employee exposure under this section must be taken
						  during periods of maximum expected concentrations of acrylonitrile in the
						  employee's breathing zone. A minimum of three (3) measurements should be taken
						  on one work shift. The average of all measurement taken is an estimate of the
						  employee's ceiling exposure.
3. Monitoring Techniques: The sampling and analysis
						  under this section may be performed by collecting the acrylonitrile vapor on
						  charcoal adsorption tubes or other composition adsorption tubes, with
						  subsequent chemical analysis. Sampling and analysis may also be performed by
						  instruments such as real-time continuous monitoring systems, portable
						  direct-reading instrument or passive dosimeters. Analysis of resultant samples
						  should be by gas chromatography.
Appendix D lists methods of sampling and analysis which
						  have been tested by NIOSH and OSHA for use with acrylonitrile. NIOSH and OSHA
						  have validated modifications of NIOSH Method S-156 (see Appendix D) under
						  laboratory conditions for concentrations below 1 ppm. The employer has the
						  obligation of selecting a monitoring method which meets the accuracy and
						  precision requirements of the standard under his unique field conditions. The
						  standard requires that methods of monitoring must be accurate, to 95-percent
						  confidence level, to ±35 percent for concentrations of AN at or above 2
						  ppm, and to ±50 percent for concentrations below 2 ppm. In addition to
						  the methods described in Appendix D, there are numerous other methods available
						  for monitoring for AN in the workplace.
Since many of the duties relating to employee exposure
						  are dependent on the results of monitoring and measuring procedures, employers
						  shall assure that the evaluation of employee exposures is performed by a
						  competent industrial hygienist or other technically qualified person.
V. Protective Clothing
Employees shall be provided with, and required to wear
						  appropriate protective clothing to prevent any possibility of skin contact with
						  liquid AN. Because acrylonitrile is absorbed through the skin, it is important
						  to prevent skin contact with the liquid. Protective clothing shall include
						  impermeable coveralls or similar full-body work clothing, gloves,
						  head-coverings, and workshoes or shoe coverings, as appropriate, to protect
						  areas of the body which may come in contact with liquid AN.
Employers should ascertain that the protective garments
						  are impermeable to acrylonitrile. Non-impermeable clothing and shoes should not
						  be allowed to become contaminated with acrylonitrile. If permeable clothing
						  does become contaminated, it should be promptly removed, placed in a regulated
						  area for removal of the AN, and not worn again until the AN is removed. If
						  leather footwear or other leather garments become wet from acrylonitrile, they
						  should be replaced and not worn again, due to the ability of leather to absorb
						  acrylonitrile and hold it against the skin. Since there is no pain associated
						  with the blistering, it is essential that the employee be informed of this
						  hazard so that he or she can be protected.
Any protective clothing which has developed leaks or is
						  otherwise found to be defective should be repaired or replaced. Clean
						  protective clothing shall be provided to the employee, as necessary to assure
						  adequate protection. Whenever impervious clothing becomes wet with liquid AN,
						  it shall be washed down with water before being removed by the employee.
						  Employees are also required to wear splash-proof safety goggles where there is
						  any possibility of acrylonitrile contacting the eyes.
VI. Housekeeping and Hygiene Facilities
For purposes of complying with Article 9 of the General
						  Industry Safety Orders the following items should be emphasized
A. The workplace should be kept clean, orderly, and in
						  a sanitary condition. The employer is required to institute a leak and spill
						  detection program for operations involving liquid AN in order to detect sources
						  of fugitive AN emissions.
B. Dry sweeping and the use of compressed air is unsafe
						  for the cleaning of floors and other surfaces where liquid AN may be
						  found.
C. Adequate washing facilities with hot and cold water
						  are to be provided, and maintained in a sanitary condition. Suitable cleansing
						  agents are also to be provided to assure the effective removal of acrylonitrile
						  from the skin.
D. Change or dressing rooms with individual
						  clothes-storage facilities must be provided to prevent the contamination of
						  street clothes with acrylonitrile. Because of the hazardous nature of
						  acrylonitrile, contaminated protective clothing must be placed in a regulated
						  area designated by the employer for the removal of the AN before the clothing
						  is laundered or disposed of.
VII. Miscellaneous Precautions
A. Store acrylonitrile in tightly-closed containers in
						  a cool, well-ventilated area and take the necessary precautions to avoid an
						  explosion hazard.
B. High exposure to acrylonitrile can occur when
						  transferring the liquid from one container to another.
C. Non-sparking tools must be used to open and close
						  metal acrylonitrile containers. These containers must be effectively grounded
						  and bonded prior to pouring.
D. Never store uninhibited acrylonitrile.
E. Acrylonitrile vapors are not inhibited. They may
						  clog vents of storage tanks through the formation of polymer.
F. Use of supplied-air suits or other impervious
						  coverings may be necessary to prevent skin contact as well as to provide
						  respiratory protection where the concentration of acrylonitrile is unknown or
						  is above the ceiling limit. Supplied-air suits should be selected, used, and
						  maintained under the immediate supervision of persons knowledgeable in the
						  limitations and potential life-endangering characteristics of supplied-air
						  suits.
G. Employers shall advise employees of all areas and
						  operations where exposure to acrylonitrile could occur.
VIII. Common Operations
Common operations in which exposure to acrylonitrile is
						  likely to occur include the following: manufacture of acrylonitrile monomer;
						  synthesis of acrylic fibers, ABS, SAN and nitrile barrier plastics and resins,
						  nitrile rubber, surface coatings, specialty chemicals, use as a chemical
						  intermediate, use as a fumigant and in the cyanoethylation of
						  cotton.