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MILES AND REGULATIONS
TW* 29--Labor
50 ppm, in order to assess in a more rary standard. In a telegram to the As
CHAPTER XVII--OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DE PARTMENT OF LABOR
PART 1910--OCCUPATIONAL SAFETY AND HEALTH STANDARDS
definitive way whether that level of ex sistant Secretary of Labor, received on posure produces tumors in animals. Data' or about March 14, 1974, the President reported by Torkelson, Oyea and Rowe of the United Rubber Workers Interna (American Industrial Hygiene Associa tional Union urged the establishment of tion J 22:354-361 (1961)) indicate that an emergency temporary standard for exposure to VC at concentrations of 50 VC. During the hearing of February 15,
Emergency Temporary Standard for
ppm failed to induce tumors in rats,
Exposure to Vinyl Chloride
hamsters, rabbits, and dogs.
1. Background. Vinyl chloride (chloroethene). Chemical Abstracts Service Registry No. 75015. is a synthetic chemi cal made by oxychlorination of ethylene
or by hydrochlorination of acetylene. It is the parent compound of a series of thermoplastic resin polymers and co
polymers which are widely used for con tainers, wrapping tissues, electrical in
sulation, pipe, conduit and a variety of
other products. Vinyl chloride has been made commercially in this country since
1939 and present production is in excess
of seven billion pounds per year. Vinyl chloride (VC) Is a gas at am
bient temperature and pressure and is a
chlorinated hydrocarbon which has mod erate liver toxicity. The present standard sets a ceiling value of 500 parts per
million (ppm) (29 CFR 1910.93).
On January 22. 1974. the Occupational Safety and Health Administration was
informed by the National Institute for Occupational Safety and Health (NIOSH> that the B. F. Goodrich Chem
ical Company reported that deaths of several of its employees from a rareform of liver cancer may have been occupa
tionally related. As a result of this notifi cation, and after consultation with NIOSH and a joint inspection of the
plant by OSHA, NIOSH, and the Ken
tucky Department of Labor, a fact-find ing hearing on possible hazards involved
with the manufacture and use of both VC and polyvinyl chloride was an nounced on January 30, 1974 (39 FR 3874), and held on February 15, 1974.
The employees of the B. F. Goodrich
Chemical Company who died from an giosarcoma of the liver had an average exposure of approximately 19 years to
vinyl chloride, at unknown concentra
tions, and variable exposures to other volatile chemicals. (TR 93). Some em ployees of Union Carbide Company and Goodyear Company are also reported In a post-hearing comment from NIOSH
dated March 11, 1974, to have had ex posure to vinyl chloride and to have died from angiosarcoma of the liver. Finally,
autopsies of lour deceased employees re vealed that liver angiosarcoma tumors were histologically indistinguishable from the angiosarcoma tumors observed
in Professor Maltonl's experimental ani. mals. It is concluded therefore, that
vinyl chloride is carcinogenic for hu mans.
We therefore conclude that the present
standard for VC should be lowered from
a ceiling of 500 ppm to a celling of 50 ppm for the following reasons:
(a) In light of the evidence referred
to above Including the Maltoni experi ments demonstrating that VC is carcino
genic in animals at 250 ppm, we conclude
that VC must be considered carcino genic in man at the same level:
(b) Although Professor Maltoni did
not Induce tumors in his experimental animals at an exposure concentration of 50 ppm, these data do not support the
concept that occupational exposure of employees to concentrations of 50 ppm throughout their working lifetime would be without detrimental health effects;
2. Carcinogenicity o'f VC. Information (c) The question whether safe levels
produced at the hearing demonstrated of exposure to carcinogens exist for hu
that exposure of laboratory animals mans and, if so, what such levels would
(mostly Sprague-Dawley rats) to VC by be, is the subject of continuing scientific
inhalation at and below the current deliberation. In the case of VC. Profes
OSHA standard of 500 ppm induced sor Maltoni did not observe tumors in
tumors, Including angiosarcomas of the his animals at exposure concentrations
liver. Professor Cesare Maltoni. of the of 50 ppm. In addition. Torkelson, Oyen,
Instituto di Oncoiogia, Bologna, Italy, re and Rowe found that exposure to con
ported on a series of experiments on the centrations of 50 ppm of VC failed to in
effect of exposure of rats, mice, and duce tumors in rats, hamsters, rabbits,
hamsters to VC at concentrations of 10,- and dogs. Accordingly, there is insuf
000; 6,000; 2,500; 500; 250; and 50 ppm ficient evidence at this time to conclude
for varying periods of time (TR 43-63). that VC at concentrations of 50 ppm or
Some of the experiments have been con below poses a grave danger to humans.
cluded, and others are still ongoing. The (d) The emergency temporary stand
experimental results so far reported are ard adopted represents a substantial re
that tumors have been observed in duction in the permissible level of expo
groups of animals exposed to VC at con sure and, in our practical judgment, is
centrations as low as 250 ppm. No tumors the lowest level that can be complied
have been observed in the group of ani with immediately: and
mals exposed to VC at a concentration (e) This standard will be in effect for
of 50 ppm. It also appears so far that a period of no longer than six months,
the total number of tumors, as well as during which time the whole question of
the numbers of angiosarcomas of the possible safe exposure of humans to VC liver, decrease as the concentrations of will be reconsidered more fully and in VC are reduced to 250 ppm. Finally, the light of more information, including
1974, the Industrial Union Department.
AFL-CIO, and the United Rubber Work ers International Union made a jo,n*
petition for an emergency temporary standard for VC (TR 141-148). which was also joined by the Oil, Chemical and
Atomic Workers International Union (Tit 37). At the same hearing, several participants urged, on the other hand, a regular rulemaking proceeding as the most suitable for the orderly develop ment of relevant information (TR 112, 180).
The petitions for an emergency tem porary standard specified in detail the
contents of the standard requested. In substance, the request is to issue a com prehensive fully-developed standard based on the recommendations of the
Standards Advisory Committee on Car cinogens submitted to the Assistant Sec
retary of Labor on or about August 27, 1973. The recommendations are farranging, and cover special categories ol operations, signs and labels, medical sur
veillance, reporting, etc., including a per mit system for the use of a carcinogen.
We agree that an emergency tempo
rary standard Is necessary; we cannot say on the basis of the information developed so far that a comprehensive standard, such as the one requested, is either neces sary or even desirable. It has been de cided to promulgate a standard contain
ing only those essential provisions which are deemed necessary to provide protec tion to employees from grave dancer
until a regular rulemaking proceeding in
accordance with sections 6 (b) and <c) of the Act can be concluded. The rea sons for a decision to establish a ceiling
value of 50 ppm have already been stated. A decision on other possible, ap
propriate provisions is best made after consideration of all relevant data and views that Interested persons may sub
mit during the proceeding soon to be
initiated. With respect to arguments in opposi
tion to issuance of an emergency tem
porary standard, the concern and efforts of several companies participating at the
hearing for the protection of their em ployees are recognized. It may also be that some employers in some plants have fully complied with the interim controls
recommended by NIOSH on January 30, 1974. There is, however, reason to believe that employees are currently being ex posed to VC at concentrations well above 50 ppm. This was asserted several times at the hearing, and not seriously ques tioned. Moreover, a report, dated March 1974, of a survey by the staff of the Office of Standards Development. OSHA. of several facilities manufacturing VC and polyvinyl chloride revealed concentra tions for some job classifications as high
another experiment by Professor Mal experiments which are under way at this as 229 ppm. Therefore, a regulation is
toni is underway involving the exposure time (TR 47, 49. 71-74).
considered necessary to provide, immedi
of 300 animals to VC at concentrations of 3. Petitions for an emergency tempo ately, adequate protection to workers ex-
toozTzez
RDCRAL REGISTER. VOL 39, NO. 67--FRIDAY, AMR 5, 1*74
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RULES AND REGULATIONS
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posed to VC. Also, the eight-hour, timeweighted average standard suggested by several participants at the hearing (see, for instance, TRTW). has been rejected.
The March 1974 report of the survey re vealed that several kinds of work or op erations are of short duration. Loading
or unloading of a tank car may require approximately 15 minutes. The cleaning of a reactor may require approximately
half an hour. An eight-hour, timeweighted average standard would permit exposure to VC at concentrations of 400
ppm for one hour. Such upward excur
sions. several times the 50 ppm level, can not be permuted to occur.
4. The standard. The standard set out below contains only the requirements deemed necessary to provide protection before the conclusion of the rulemaking proceeding to oe commenced shortly.
Because exposure to VC is hazardous,
and because such exposure can occur in the processes of synthesizing or polym erizing of VC or m the handling of VC polymers or copolymers which contain absorbed VC. thus standard applies to all such processes and to the handling, re acting, manufacturing, processmg, re leasing, repackaging, or storage of any of these materials. The monitoring require ments serve t;vo purposes, to trigger into operation a compliance program and to check the effectiveness of the program. Also, engineering controls are favored for compliance, and resonators are intended
to provide protection until such controls can be installed or in cases where such
controls are not feasible. Accordingly, by reason of the foregoing
and on the basis of the record of the hearing ol February 15. 1S74, with ex hibits, the written submissions received before the hearing pursuant to the notice of the hearing, the post-hearing written submissions by the participants at the hearing, the March 1974 report of a fact finding survey recommendations received from NIOSH. and the other data referred
to herein, it is found (1 > that VC at con centrations in excess of 50 ppm is physi cally harmful and carcinogenic: (21 that
exposure to VC at concentrations in ex cess of a concentration of 50 ppm poses a grave danger to employees: (3) that em
ployees are presently exposed to VC at concentrations in excess of 50 ppm: and (4) that the emergency temporary stand
ard set out below is necessary to provide Immediate protection to employees from such danger.
Pursuant to section 6(c) of the Occu
pational Safety and Health Act of 1970, a proceeding will commence shortly In accordance with section 6(b) of the Act, in which the emergency temporary standard will serve as a proposed rule, together with other subsidiary rules. As soon as possible a draft environmental impact statement will be filed with the
President's Council on Environmental Quality, and copies will be provided to other appropriate Federal agencies for
their comments.
Pursuant to sections 6(c) and 8(c) (3)
of the Williams-Steiger Occupational
Safety and Health Act of 1970 (84 Stat.
1596, 1599; (29 UB.C. 655, 657)), and
Secretary of Labor's Order No. 12-71 (36 PR 8754), 29 CFR Part 1910 Is amended by -adding thereto a new ! 1910.93q to read as set forth below. In addition, pur suant to section 4(b) (2) of the Act (84 Stat. 1592; (29 U.S.C. 653)), the stand ard in the new 5 1910.93q is determined to be more effective thin the corre sponding standards now in Subpart B of Part 1910. in Parts 1915, 1916, 1917, 1918, and 1926 of title 29. Code of Federal Reg ulations, and in Part 50-204 of Title 41 of the Code of Federal P.egulations. There fore. these corresponding standards are superseded by the new standard in 3 1910.93q.
1. In 29 CFR Part 1910. 5 1910.93 Is amended by deleting from Table G-l the line: " C Vinyl chloride 500 1300".
2. Part 1910 of Title 29 of the Code of Federal Regulations is amended by adding thereto a new 5 1910.93q to read as follows:
1910.93q Vinyl chloride.
(a) Scope and application. (1) This section applies to any area or operation in which vinyl chloride (chloroethene). Chemical Abstracts Service Registry Number 75015, is manufactured, reacted, handled, processed, released, repacked, or stored.
(21 This section does not apply to the handling, storage, or other use of vinyl chloride polymers and copolymers in the form of fabricated products.
(b) Permissible exposure. The occupa tional environment shall be controlled so that no employee is exposed to vinyl chloride at a concentration in excess of 50 parts per million (ppm). (127J) mg/cum).
(c> Monitoring--(1) Initial monitor ing. As soon as possible but not later than April 22, 1974, every employer of an em ployee working in an area or operation in which yinyl chloride is manufactured, re acted. handled, processed, released, re packed. or stored shall begin monitoring the ambient air of the area to determine whether it contains vinyl chloride in con centrations in excess of 50 ppm.
(2) Frequency. Monitoring of a suffi cient number of employees so that a representative sample of exposures to vinyl chloride may be determined shall be accomplished not less frequently than weekly until all results for three consecu tive weeks are at or below 50 ppm. There after, monitoring shall be conducted not less frequently than monthly so long as
the concentrations of vinyl chloride do not exceed 50 ppm. If a monitoring sam ple reveals vinyl chloride in concentra tions in excess of 50 ppm, weekly moni toring shall be resumed until all results
for three consecutive weeks are at or be low 50 ppm.
(3) Method of monitoring. Personnel monitoring shall be accomplished by col lecting samples by suitable devices worn by the employee. The samples shall be analyzed by gas chromatography or by
any other method which is of equivalent sensitivity. The analytical procedure shall be sensitive to 5 ppm of vinyl chlo ride in air with an accuracy of 20 per cent for a ten minute air sample.
(4) Employee observation of monitor ing. Employees working In an area or operation whose ambient air is moni tored, or their representatives, shall be
given a reasonable opportunity to observe the personnel monitoring required by this section.
(5) Recordkeeping. The results of all monitoring shall be recorded in writing. The records shall be retained for at least 5 years and shall be made available for inspection and copying by representa tives of the Assistant Secretary of Labor for Occupational Safety and Health and the Director of the National Insti tute for Occupational Safety and Health (NIOSH).
(6) Employee access. Each employee and former employee shall have access to such records of the results of monitoring required by this section as will indicate his own exposure to airborne concentra tions of vinyl chloride.
(7) Employee notification. Each em ployer shall promptly notify any em ployee who has been or is being exposed to vinyl chloride in concentrations in ex cess of 50 ppm, and shall Inform him of the corrective action being taken.
(d> Compliance. (1) Whenever any monitoring sample reveals vinyl chloride at a concentration in excess of 50 ppm, or whenever any accident, such as rup ture of equipment or spillage, indicates the likelihood of a greater than usual release of vinyl chloride into the ambient air. all employees exposed to such con centrations shall be withdrawn to a safe area and shall not be permitted to re enter the work area unless they wear either Type C continuous flow or pres sure demnrui air supplied respirators or self-contained breathing apparatus.
(2) Work which may reasonably be expected to release vinyl chloride in con centrations in excess of 50 ppm, such as repair, maintenance or cleaning of re actors or other equipment containing vinyl chloride, shall be accomplished only by employees wearing Type C continuous flow or pressure demand air supplied res pirators or self-contained breathing ap paratus.
(3) In any case covered by para graphs (d)(1) or (d)(2) of this section, in addition to providing the required respirators, the employer shall examine and analyze the source of the excessive concentrations of vinyl chloride in order to determine feasible engineering or op erational controls appropriate to reduce the airborne concentrations to the per-
missable level. Such controls shall he implemented as quickly as possible.
<4> Periodic tests shall be conducted for equipment leaks and for emissions of vinyl chloride which may result from work practices.
3. In 29 CFR Part 1910, 5 1910.19 is revised to read as follows:
1910.19 Special provisions for air con
taminants.
(a) Asbestos dust. Section 1910.93a
shall apply to the exposure of every em ployee to asbestos dust in every employ ment and place of employment covered by 91910.12. 91910.13. 91910.14. 9 1910.15, or 9 1910.16, In lieu of any dif-
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(b) Vinyl chloride. Section 1910.93q shall apply to the exposure of every em ployee to vinyl chloride in every employ ment and place of employment covered by i 1910.12, 1 1910.13, 11910.14, 11910.15, or (1910.16. in lieu of any dif ferent standard on exposure to vinyl chloride which would otherwise be ap plicable by virtue of any of thoee sec tions.
Effective date. These amendments shall become effective on April 5, 1974.
(Sees. 4, S. and 8, 84 Stat. 1593,1594.1599 (39 IT.S.C. <53. 856, 457); Secretary, of Labor's Order No. 13-71,84 FB 8754.)
Signed at Washington, DC., this 2d day of April 1974.
John Stxndih, Assistant Secretary of Labor. (PR Doc.74-7890 Piled 4-4-74;8:45 am]
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