Disclaimer: These guidelines were developed under contract using generally accepted secondary sources. The protocol used by the contractor for surveying these data sources was developed by the National Institute for Occupational Safety and Health (NIOSH), the Occupational Safety and Health Administration (OSHA), and the Department of Energy (DOE). The information contained in these guidelines is intended for reference purposes only. None of the agencies have conducted a comprehensive check of the information and data contained in these sources. It provides a summary of information about chemicals that workers may be exposed to in their workplaces. The secondary sources used for supplements 111 and 1V were published before 1992 and 1993, respectively, and for the remainder of the guidelines the secondary sources used were published before September 1996. This information may be superseded by new developments in the field of industrial hygiene. Therefore readers are advised to determine whether new information is available.
OCCUPATIONAL SAFETY AND HEALTH GUIDELINE FOR DIPROPYLENE GLYCOL METHYL ETHER
INTRODUCTION
This guideline summarizes pertinent information about dipropylene glycol
methyl ether for workers and employers as well as for physicians, industrial
hygienists, and other occupational safety and health professionals who may
need such information to conduct effective occupational safety and health
programs. Recommendations may be superseded by new developments in these
fields; readers are therefore advised to regard these recommendations as
general guidelines and to determine whether new information is available.
SUBSTANCE IDENTIFICATION
* Formula
C(7)H(16)O(3)
* Structure
(For Structure, see paper copy)
* Synonyms
Dipropylene glycol monomethyl ether;
1-(2-methoxyisopropoxy)-2-propanol; dowanol 50B; propasol; solvent
DM; poly-solv; DPM solvent; UCAR solvent 2LM; arcosolv; dowanol DPM glycol
ether
* Identifiers
1. CAS No.: 34590-94-8
2. RTECS No.: JM1575000
3. Specific DOT number: None.
4. Specific DOT label: None.
* Appearance and odor Dipropylene glycol methyl ether is a colorless
liquid with a weak, ether-like odor.
CHEMICAL AND PHYSICAL PROPERTIES
* Physical data
1. Molecular weight: 148.20
2. Boiling point (at 760 mm Hg): 190 degrees C (374 degrees F)
3. Specific gravity: 0.95 at 20 degrees C (68 degrees F)
4. Vapor density: 5.11
5. Melting point: -80 degrees C (-112 degrees F)
6. Vapor pressure at 20 degrees C (68 degrees F): 0.3 mm Hg
7. Solubility: Completely miscible with water, acetone, ethanol, benzene,
carbon tetrachloride, ether, methanol, monochlorobenzene, petroleum ether,
and VM&P naphtha.
8. Evaporation rate: Data not available.
* Reactivity
1. Conditions contributing to instability: Heat or flame .
2. Incompatibilities: Contact between dipropylene glycol methyl ether and
strong oxidizing agents may cause fires and explosions.
3. Hazardous decomposition products: Toxic gases and vapors (such as
oxides of carbon) may be released in a fire involving dipropylene glycol
methyl ether.
4. Special precautions: None reported.
* Flammability
The National Fire Protection Association has assigned a flammability
rating of 2 (moderate fire hazard) to dipropylene glycol methyl
ether.
1. Flash point: 85 degrees C (185 degrees F) (open cup)
2. Autoignition temperature: Data not available.
3. Flammable limits in air: Data not available.
4. Extinguishant: Use water fog, dry chemical, alcohol foam, and carbon
dioxide to extinguish fires involving dipropylene glycol methyl ether.
Fires involving dipropylene glycol methyl ether should be fought
upwind from the maximum distance possible. Isolate the hazard area and deny
access to unnecessary personnel. Use water spray to cool fire-exposed
containers. Water or foam may cause frothing. Firefighters should wear a
full set of protective clothing and self-contained breathing apparatus when
fighting fires involving dipropylene glycol methyl ether.
EXPOSURE LIMITS
* OSHA PEL
The current Occupational Safety and Health Administration (OSHA)
permissible exposure limit (PEL) for dipropylene glycol methyl ether is 100
parts per million (ppm) parts of air (600 milligrams per cubic meter
(mg/m(3)) as an 8-hour time-weighted average (TWA) concentration. The OSHA
PEL also bears a "Skin" notation, which indicates that the cutaneous route of
exposure (including mucous membranes and eyes) contributes to overall
exposure [29 CFR 1910.1000, Table Z-1].
* NIOSH REL
The National Institute for Occupational Safety and Health (NIOSH)
has established recommended exposure limits (RELs) for dipropylene glycol
methyl ether of 100 ppm (600 mg/m(3)) as a TWA for up to a 10-hour workday
and a 40-hour workweek and 150 ppm (900 mg/m(3)) as a short-term exposure
limit (STEL). NIOSH also assigns a "Skin" notation to dipropylene glycol
methyl ether [NIOSH 1992].
* ACGIH TLV
The American Conference of Governmental Industrial Hygienists
(ACGIH) has assigned dipropylene glycol methyl ether threshold limit values
(TLVs) of 100 ppm (606 mg/m(3)) as a TWA for a normal 8-hour workday and a
40-hour workweek and a short-term exposure limit (STEL) of 150 ppm (909
mg/m(3)) for periods not to exceed 15 minutes. Exposures at the STEL
concentration should not be repeated more than four times a day and should be
separated by intervals of at least 60 minutes. The ACGIH also assigns a
"Skin" notation to dipropylene glycol methyl ether [ACGIH 1994, p.
20].
* Rationale for Limits
The NIOSH limits are based on the risk of narcotic effects and mild
irritation of the nose and eyes [NIOSH 1992].
The ACGIH limits are based on the risk of irritation and central
nervous system impairment [ACGIH 1991, p. 520].
HEALTH HAZARD INFORMATION
* Routes of Exposure
Exposure to dipropylene glycol methyl ether can occur through
inhalation, ingestion, and eye or skin contact [Sittig 1991].
* Summary of toxicology 1. Effects on Animals: Dipropylene glycol
methyl ether causes narcosis in animals at very high concentrations. The
acute oral LD(50)s in rats and dogs are 5,135 mg/kg and 7,500 mg/kg,
respectively [NIOSH 1991]. Death resulted from central nervous system
depression and respiratory failure [Clayton and Clayton 1982]. The dermal
LD(50) in rabbits is 9,500 mg/kg [ACGIH 1991]. Rats exposed for 7 hours to
500 ppm showed signs of mild narcosis but recovered rapidly [Hathaway et al.
1991]. Repeated daily exposures to 300-400 ppm for more than 100 days caused
minor cellular changes in the liver of rabbits, monkeys, and guinea pigs, but
not in the liver of rats [Hathaway et al. 1991]. Topical administration of 10
mg/kg dipropylene glycol methyl ether five times per week for 13 weeks to the
shaved skin of rabbits caused death in six of seven rabbits [Clayton and
Clayton 1982]. Direct eye contact or eye exposure to a high ambient
concentration results in slight and transient eye irritation but does not
cause permanent damage [Grant 1986].
2. Effects on Humans: Dipropylene glycol methyl ether is an irritant of
the eyes, nose, and throat. At very high concentrations, it is expected that
it would also cause narcosis in humans. The lowest concentrations that
produce nasal irritation of eye, throat, and upper respiratory tract
irritation are 35 and 75 ppm, respectively [Clayton and Clayton 1982]. The
eye irritation caused by these concentrations or by direct contact of the eye
with the liquid is transient [Hathaway et al. 1991]. The lowest
concentration which produced an intolerable odor was 80 ppm; for most
persons, its odor is transiently objectionable at 100 ppm [ACGIH 1991;
Clayton and Clayton 1982]. Central nervous system impairment occurred in one
subject exposed to 1,000 ppm [ACGIH 1991].
* Signs and symptoms of exposure
1. Acute exposure: Irritation of the eyes, nose, and throat may occur and
be associated with symptoms of burning, itching, runny nose, and nose and
throat soreness. At very high concentrations, central nervous system
impairment may occur with sleepiness, headache, inability to concentrate, and
other symptoms of narcosis [Sittig 1991].
2. Chronic exposure: No signs or symptoms of chronic exposure to
dipropylene glycol methyl ether have been reported in humans.
EMERGENCY MEDICAL PROCEDURES
* Emergency medical procedures: [NIOSH to supply]
5. Rescue: Remove an incapacitated worker from further exposure and
implement appropriate emergency procedures (e.g., those listed on the
Material Safety Data Sheet required by OSHA's Hazard Communication Standard
[29 CFR 1910.1200]). All workers should be familiar with emergency
procedures, the location and proper use of emergency equipment, and methods
of protecting themselves during rescue operations.
EXPOSURE SOURCES AND CONTROL METHODS
The following operations may involve dipropylene glycol methyl ether and
lead to worker exposures to this substance:
* The manufacture and transportation of dipropylene glycol methyl ether *
Used as a general and high-boiling solvent for oils, greases, lacquers,
paints, nitrocellulose and synthetic resins; used in application of
water-based surface coatings * Used as a coupling and dispersing agent in
manufacture and application of printing pastes, dyes, in ks, cosmetics, and
water-based polishes * Used in manufacture of latex paints, lacquers,
enamels, adhesives, and leather protective coatings * Used as slimicides
in food packaging and adhesives in food industry;
used as a solvent in hard-surface liquid household cleaners * Used as a
heat-transfer agent in hydraulic brake fluid
Methods that are effective in controlling worker exposures to dipropylene
glycol methyl ether, depending on the feasibility of implementation, are as
follows:
* Process enclosure * Local exhaust ventilation * General dilution
ventilation * Personal protective equipment
Workers responding to a release or potential release of a hazardous
substance must be protected as required by paragraph (q) of OSHA's Hazardous
Waste Operations and Emergency Response Standard [29 CFR 1910.120].
Good sources of information about control methods are as follows:
1. ACGIH [1992]. Industrial ventilation--a manual of recommended
practice. 21st ed. Cincinnati, OH: American Conference of Governmental
Industrial Hygienists.
2. Burton DJ [1986]. Industrial ventilation--a self study companion.
Cincinnati, OH: American Conference of Governmental Industrial Hygienists.
3. Alden JL, Kane JM [1982]. Design of industrial ventilation systems.
New York, NY: Industrial Press, Inc.
4. Wadden RA, Scheff PA [1987]. Engineering design for control of
workplace hazards. New York, NY: McGraw-Hill.
5. Plog BA [1988]. Fundamentals of industrial hygiene. Chicago, IL:
National Safety Council.
MEDICAL SURVEILLANCE
OSHA is currently developing requirements for medical surveillance. When
these requirements are promulgated, readers should refer to them for
additional information and to determine whether employers whose employees are
exposed to dipropylene glycol methyl ether are required to implement medical
surveillance procedures.
* Medical Screening
Workers who may be exposed to chemical hazards should be monitored
in a systematic program of medical surveillance that is intended to prevent
occupational injury and disease. The program should include education of
employers and workers about work-related hazards, early detection of adverse
health effects, and referral of workers for diagnosis and treatment. The
occurrence of disease or other work-related adverse health effects should
prompt immediate evaluation of primary preventive measures (e.g., industrial
hygiene monitoring, engineering controls, and personal protective equipment).
A medical surveillance program is intended to supplement, not replace, such
measures. To detect and control work-related health effects, medical
evaluations should be performed (1) before job placement, (2) periodically
during the term of employment, and (3) at the time of job transfer or
termination.
* Preplacement medical evaluation
Before a worker is placed in a job with a potential for exposure to
dipropylene glycol methyl ether, a licensed health care professional should
evaluate and document the worker's baseline health status with thorough
medical, environmental, and occupational histories, a physical examination,
and physiologic and laboratory tests appropriate for the anticipated
occupational risks. These should concentrate on the function and integrity
of the respiratory system. Medical surveillance for respiratory disease
should be conducted using the principles and methods recommended by the
American Thoracic Society.
A preplacement medical evaluation is recommended to assess medical
conditions that may be aggravated or may result in increased risk when a
worker is exposed to dipropylene glycol methyl ether at or below the
prescribed exposure limit. The health care professional should consider the
probable frequency, intensity, and duration of exposure as well as the nature
and degree of any applicable medical condition. Such conditions (which should
not be regarded as absolute contraindications to job placement) include a
history and other findings consistent with diseases of the respiratory
system.
* Periodic medical evaluations
Occupational health interviews and physical examinations should be
performed at regular intervals during the employment period, as mandated by
any applicable Federal, State, or local standard. Where no standard exists
and the hazard is minimal, evaluations should be conducted every 3 to 5 years
or as frequently as recommended by an experienced occupational health
physician. Additional examinations may be necessary if a worker develops
symptoms attributable to dipropylene glycol methyl ether exposure. The
interviews, examinations, and medical screening tests should focus on
identifying the adverse effects of dipropylene glycol methyl ether on the
respiratory system. Current health status should be compared with the
baseline health status of the individual worker or with expected values for a
suitable reference population.
* Termination medical evaluations
The medical, environmental, and occupational history interviews, the
physical examination, and selected physiologic or laboratory tests that were
conducted at the time of placement should be repeated at the time of job
transfer or termination to determine the worker's medical status at the end
of his or her employment. Any changes in the worker's health status should
be compared with those expected for a suitable reference
population.
* Biological monitoring
Biological monitoring involves sampling and analyzing body tissues
or fluids to provide an index of exposure to a toxic substance or metabolite.
No biological monitoring test acceptable for routine use has yet been
developed for dipropylene glycol methyl ether.
WORKPLACE MONITORING AND MEASUREMENT
Determination of a worker's exposure to airborne dipropylene glycol methyl
ether is made using a charcoal tube (100/50 mg sections, 20/40 mesh). Samples
are collected at a maximum flow rate of 0.1 liter/minute until a maximum
collection volume of 10 liters is reached. The sample is then treated with
95:5 methylene chloride:methanol. Analysis is conducted by gas
chromatography using a flame ionization detector (GC/FID). This method (OSHA
101) is fully validated and is described in the OSHA Computerized Information
System [OSHA 1994].
PERSONAL HYGIENE PROCEDURES
If dipropylene glycol methyl ether contacts the skin, workers should
immediately wash the affected areas with soap and water.
Clothing contaminated with dipropylene glycol methyl ether should be removed
immediately, and provisions should be made for the safe removal of the
chemical from the clothing. Persons laundering the clothes should be
informed of the hazardous properties of dipropylene glycol methyl ether,
particularly its potential for causing eye, nose, and throat irritation.
A worker who handles dipropylene glycol methyl ether should thoroughly wash
hands, forearms, and face with soap and water before eating, using tobacco
products, using toilet facilities, applying cosmetics, or taking medication.
Workers should not eat, drink, use tobacco products, apply cosmetics, or
take medication in areas where dipropylene glycol methyl ether or a solution
containing dipropylene glycol methyl ether is handled, processed, or stored.
STORAGE
Dipropylene glycol methyl ether should be stored in a cool, dry,
well-ventilated area in tightly sealed containers that are labeled in
accordance with OSHA's Hazard Communication Standard [29 CFR 1910.1200].
Containers of dipropylene glycol methyl ether should be stored out of direct
sunlight, ignition sources, and protected from physical damage, and should be
stored separately from strong oxidizing agents. Containers of dipropylene
glycol methyl ether should be inspected and monitored periodically. Empty
containers should be handled appropriately.
SPILLS AND LEAKS
In the event of a spill or leak involving dipropylene glycol methyl ether,
persons not wearing protective equipment and clothing should be restricted
from contaminated areas until cleanup has been completed. The following
steps should be undertaken following a spill or leak:
1. Notify safety personnel.
2. Remove all sources of heat and ignition.
3. Ventilate potentially explosive atmospheres.
4. Do not touch the spilled material; stop the leak if it is possible to
do so without risk.
5. Use non-sparking tools.
6. Absorb spills in vermiculite, dry sand, earth, or similar material and
deposit in sealed container.
SPECIAL REQUIREMENTS
U.S. Environmental Protection Agency (EPA) requirements for emergency
planning, reportable quantities of hazardous releases, community
right-to-know, and hazardous waste management may change over time. Users
are therefore advised to determine periodically whether new information is
available.
* Emergency planning requirements
dipropylene glycol methyl ether is not subject to EPA emergency
planning requirements under the Superfund Amendments and Reauthorization Act
(SARA) (Title III) in 42 USC 11022.
* Reportable quantity requirements for hazardous releases
A hazardous substance release is defined by EPA as any spilling,
leaking, pumping, pouring, emitting, emptying, discharging, injecting,
escaping, leaching, dumping, or disposing into the environment (including the
abandonment or discarding of contaminated containers) of hazardous
substances. In the event of a release that is above the reportable quantity
for that chemical, employers are required to notify the proper Federal,
State, and local authorities [40 CFR 355.40].
Employers are not required by the emergency release notification
provisions in 40 CFR Part 355.40 to notify the National Response Center of an
accidental release of dipropylene glycol methyl ether; there is no reportable
quantity for this substance.
* Community right-to-know requirements
Employers are not required by EPA in 40 CFR Part 372.30 to submit a
Toxic Chemical Release Inventory form (Form R) to EPA reporting the amount of
dipropylene glycol methyl ether emitted or released from their facility
annually.
* Hazardous waste management requirements
EPA considers a waste to be hazardous if it exhibits any of the
following characteristics: ignitability, corrosivity, reactivity, or
toxicity as defined in 40 CFR 261.21-261.24. Under the Resource Conservation
and Recovery Act (RCRA) [40 USC 6901 et seq.], EPA has specifically listed
many chemical wastes as hazardous. Although dipropylene glycol methyl ether
is not specifically listed as a hazardous waste under RCRA, EPA requires
employers to treat waste as hazardous if it exhibits any of the
characteristics discussed above.
Providing detailed information about the removal and disposal of
specific chemicals is beyond the scope of this guideline. The U.S.
Department of Transportation, EPA, and State and local regulations should be
followed to ensure that removal, transport, and disposal of this substance
are conducted in accordance with existing regulations. To be certain that
chemical waste disposal meets EPA regulatory requirements, employers should
address any questions to the RCRA hotline at (703) 412-9810 (in the
Washington, D.C. area) or toll-free at (800) 424-9346 (outside Washington,
D.C.). In addition, relevant State and local authorities should be contacted
for information on any requirements they may have for the waste removal and
disposal of this substance.
RESPIRATORY PROTECTION
* Conditions for respirator use
Good industrial hygiene practice requires that engineering controls
be used where feasible to reduce workplace concentrations of hazardous
materials to the prescribed exposure limit. However, some situations may
require the use of respirators to control exposure. Respirators must be worn
if the ambient concentration of dipropylene glycol methyl ether exceeds
prescribed exposure limits. Respirators may be used (1) before engineering
controls have been installed, (2) during work operations such as maintenance
or repair activities that involve unknown exposures, (3) during operations
that require entry into tanks or closed vessels, and (4) during emergencies.
Workers should only use respirators that have been approved by NIOSH and the
Mine Safety and Health Administration (MSHA).
* Respiratory protection program
Employers should institute a complete respiratory protection program
that, at a minimum, complies with the requirements of OSHA's Respiratory
Protection Standard [29 CFR 1910.134]. Such a program must include
respirator selection, an evaluation of the worker's ability to perform the
work while wearing a respirator, the regular training of personnel,
respirator fit testing, periodic workplace monitoring, and regular respirator
maintenance, inspection, and cleaning. The implementation of an adequate
respiratory protection program (including selection of the correct
respirator) requires that a knowledgeable person be in charge of the program
and that the program be evaluated regularly. For additional information on
the selection and use of respirators and on the medical screening of
respirator users, consult the latest edition of the NIOSH Respirator Decision
Logic [NIOSH 1987b] and the NIOSH Guide to Industrial Respiratory Protection
[NIOSH 1987a].
PERSONAL PROTECTIVE EQUIPMENT
Workers should use appropriate personal protective clothing and equipment
that must be carefully selected, used, and maintained to be effective in
preventing skin contact with dipropylene glycol methyl ether. The selection
of the appropriate personal protective equipment (PPE) (e.g., gloves,
sleeves, encapsulating suits) should be based on the extent of the worker's
potential exposure to dipropylene glycol methyl ether. There are no
published reports on the resistance of various materials to permeation by
dipropylene glycol methyl ether.
To evaluate the use of PPE materials with dipropylene glycol methyl ether,
users should consult the best available performance data and manufacturers'
recommendations. Significant differences have been demonstrated in the
chemical resistance of generically similar PPE materials (e.g., butyl)
produced by different manufacturers. In addition, the chemical resistance of
a mixture may be significantly different from that of any of its neat
components.
Any chemical-resistant clothing that is used should be periodically
evaluated to determine its effectiveness in preventing dermal contact. Safety
showers and eye wash stations should be located close to operations that
involve dipropylene glycol methyl ether.
Splash-proof chemical safety goggles or face shields (20 to 30 cm long,
minimum) should be worn during any operation in which a solvent, caustic, or
other toxic substance may be splashed into the eyes.
In addition to the possible need for wearing protective outer apparel (e.g.,
aprons, encapsulating suits), workers should wear work uniforms, coveralls,
or similar full-body coverings that are laundered each day. Employers should
provide lockers or other closed areas to store work and street clothing
separately. Employers should collect work clothing at the end of each work
shift and provide for its laundering. Laundry personnel should be informed
about the potential hazards of handling contaminated clothing and instructed
about measures to minimize their health risk.
Protective clothing should be kept free of oil and grease and should be
inspected and maintained regularly to preserve its effectiveness.
Protective clothing may interfere with the body's heat dissipation,
especially during hot weather or during work in hot or poorly ventilated work
environments.
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