(1)
Physical and chemical data:
(a) Substance
identification:
(i) Synonyms: Dihydrooxirene,
dimethylene oxide, EO, 1,2-epoxyethane, EtO, ETO, oxacyclopropane, oxane,
oxidoethane, alpha/beta-oxidoethane, oxiran, oxirane.
(ii) Formula:
(C2H4O).
(iii) Molecular weight: 44.06.
(b) Physical data:
(i) Boiling point (760 mm Hg): 10.70°C
(51.3°F);
(ii) Specific gravity
(water = 1): 0.87 (at 20°C or 68°F);
(iii) Vapor density (air = 1):
1.49;
(iv) Vapor pressure (at
20°C): 1,095 mm Hg;
(v)
Solubility in water: Complete;
(vi)
Appearance and odor: Colorless liquid; gas at temperature above 10.7°F or
51.3°C with ether-like odor above 700 ppm.
(2) Fire, explosion, and reactivity hazard
data:
(a) Fire:
(i) Flash point; Less than 0°F (open
cup);
(ii) Stability: Decomposes
violently at temperatures above 800°F;
(iii) Flammable limits in air, percent by
volume: Lower: 3, Upper: 100;
(iv)
Extinguishing media: Carbon dioxide for small fires, polymer or alcohol foams
for large fires;
(v) Special
firefighting procedures: Dilution of ethylene oxide with 23 volumes of water
renders it nonflammable;
(vi)
Unusual fire and explosion hazards: Vapors of EtO will burn without the
presence of air or other oxidizers. EtO 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 EtO is being used.
(vii) For purposes of compliance with the
requirements of WAC
296-24-330,
EtO is classified as
a flammable gas. For example, 7,500 ppm, approximately one-fourth of the lower
flammable limit, would be considered to pose a potential fire and explosion
hazard.
(viii) For purposes of
compliance with WAC
296-24-585,
EtO is classified as
a Class B fire hazard.
(ix) For
purpose of compliance with chapter
296-24 WAC Part L, and WAC
296-800-280, locations classified
as hazardous due to the presence of
EtO shall be Class I.
(b) Reactivity:
(i) Conditions contributing to instability:
EtO will polymerize violently if contaminated with aqueous alkalies, amines,
mineral acids, metal chlorides, or metal oxides. Violent decomposition will
also occur at temperatures above 800°F;
(ii) Incompatibilities: Alkalines and
acids;
(iii) Hazardous
decomposition products: Carbon monoxide and carbon dioxide.
(3) Spill, leak, and
disposal procedures:
(a) If
EtO is spilled or
leaked, the following steps should be taken:
(i) Remove all ignition sources.
(ii) The area should be evacuated at once and
reentered only after the area has been thoroughly ventilated and washed down
with water.
(b) Persons
not wearing appropriate protective equipment should be restricted from areas of
spills or leaks until cleanup has been completed.
(c) Waste disposal method: Waste material
should be disposed of in a manner that is not hazardous to employees or to the
general population. In selecting the method of waste disposal, applicable
local, state, and federal regulations should be consulted.
(4) Monitoring and measurement procedures:
(a) Exposure above the permissible exposure
limit:
(i) Eight-hour exposure evaluation:
Measurements taken for the purpose of determining employee exposure under this
section are best taken with consecutive samples covering the full shift. Air
samples should be taken in the employee's breathing zone (air that would most
nearly represent that inhaled by the employee.)
(ii) Monitoring techniques: The sampling and
analysis under this section may be performed by collection of the EtO 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 instruments, or passive dosimeters as long as measurements taken using
these methods accurately evaluate the concentration of EtO in employees'
breathing zones.
(iii) Appendix D
describes the validated method of sampling and analysis which has been tested
by OSHA for use with EtO. Other available methods are also described in
Appendix D. The employer has the obligation of selecting a monitoring method
which meets the accuracy and precision requirements of the standard under
his/her unique field conditions. The standard requires that the method of
monitoring should be accurate, to a ninety-five percent confidence level, to
plus or minus twenty-five percent for concentrations of EtO at 1 ppm, and to
plus or minus thirty-five percent for concentrations at 0.5 ppm. In addition to
the method described in Appendix D, there are numerous other methods available
for monitoring for EtO in the workplace. Details on these other methods have
been submitted by various companies to the rulemaking record, and are available
at the OSHA Docket Office.
(b) Since many of the duties relating to
employee exposure are dependent on the results of measurement procedures,
employers should assure that the evaluation of employee exposures is performed
by a technically qualified person.
(5) Protective clothing and equipment:
(a) Employees should be provided with and be
required to wear appropriate protective clothing wherever there is significant
potential for skin contact with liquid EtO or EtO-containing solutions.
Protective clothing shall include impermeable coveralls or similar full-body
work clothing, gloves, and head coverings, as appropriate to protect areas of
the body which may come in contact with liquid EtO or EtO-containing
solutions.
(b) Employers should
ascertain that the protective garments are impermeable to EtO. Permeable
clothing, including items made of rubber, and leather shoes should not be
allowed to become contaminated with liquid EtO. If permeable clothing does
become contaminated, it should be immediately removed, while the employer is
under an emergency deluge shower. If leather footwear or other leather garments
become wet from EtO they should be discarded and not be worn again, because
leather absorbs EtO and holds it against the skin.
(c) Any protective clothing that has been
damaged or is otherwise found to be defective should be repaired or replaced.
Clean protective clothing should be provided to the employee as necessary to
assure employee protection. Whenever impermeable clothing becomes wet with
liquid EtO, it should be washed down with water before being removed by the
employee. Employees are also required to wear splashproof safety goggles where
there is any possibility of EtO contacting the eyes.
(6) Miscellaneous precautions:
(a) Store EtO in tightly closed containers in
a cool, well-ventilated area and take all necessary precautions to avoid any
explosion hazard.
(b) Nonsparking
tools must be used to open and close metal containers. These containers must be
effectively grounded and bonded.
(c) Do not incinerate EtO cartridges, tanks
or other containers.
(d) Employers
should advise employees of all areas and operations where exposure to EtO
occurs.
(7) Common
operations:
Common operations in which exposure to EtO is likely to occur
include the following: (a) Manufacture of EtO, (b) surfactants, (c)
ethanolamines, (d) glycol ethers, (e) specialty chemicals, and (f) use as a
sterilant in the hospital, health product and spice
industries.