NIOSH Pocket Guide to Chemical Hazards
INTRODUCTION
The NIOSH Pocket Guide to Chemical Hazards is intended as a source of
general industrial hygiene information for workers, employers, and
occupational health professionals. The Pocket Guide presents key
information and data in abbreviated tabular form for 677 chemicals or
substance groupings (e.g., manganese compounds, tellurium compounds, inorganic
tin compounds, etc.) that are found in the work environment. The industrial
hygiene information found in the Pocket Guide should help users
recognize and control occupational chemical hazards. The chemicals or
substances contained in this revision include all substances for which the
National Institute for Occupational Safety and Health (NIOSH) has recommended
exposure limits (RELs) and those with permissible exposure limits (PELs) as
found in the Occupational Safety and Health Administration (OSHA) General
Industry Air Contaminants Standard (29 CFR 1910.1000).
Background
In 1974, NIOSH (which is responsible for recommending health and safety
standards) joined OSHA (whose jurisdictions include promulgation and
enforcement activities) in developing a series of occupational health
standards for substances with existing PELs. This joint effort was labeled
the Standards Completion Program and involved the cooperative efforts of
several contractors and personnel from various divisions within NIOSH and
OSHA. The Standards Completion Program developed 380 substance-specific draft
standards with supporting documentation that contained technical information
and recommendations needed for the promulgation of new occupational health
regulations. The Pocket Guide was developed to make the technical
information in those draft standards more conveniently available to workers,
employers, and occupational health professionals. The Pocket Guide is
updated periodically to reflect new data regarding the toxicity of various
substances and any changes in exposure standards or recommendations.
Data Collection and Application
The data were collected from a variety of sources, including NIOSH policy
documents such as criteria documents and Current Intelligence Bulletins
(CIBs), and recognized references in the fields of industrial hygiene,
occupational medicine, toxicology, and analytical chemistry.
NIOSH RECOMMENDATIONS
Acting under the authority of the Occupational Safety and Health Act of 1970
(29 USC Chapter 15) and the Federal Mine Safety and Health Act of 1977
(30 USC Chapter 22), NIOSH develops and periodically revises recommended
exposure limits (RELs) for hazardous substances or conditions in the
workplace. NIOSH also recommends appropriate preventive measures to reduce or
eliminate the adverse health and safety effects of these hazards. To
formulate these recommendations, NIOSH evaluates all known and available
medical, biological, engineering, chemical, trade, and other information
relevant to the hazard. These recommendations are then published and
transmitted to OSHA and the Mine Safety and Health Administration (MSHA) for
use in promulgating legal standards.
NIOSH recommendations are published in a variety of documents. Criteria
documents recommend workplace exposure limits and appropriate preventive
measures to reduce or eliminate adverse health effects and accidental
injuries.
Current Intelligence Bulletins (CIBs) are issued to disseminate new scientific
information about occupational hazards. A CIB may draw attention to a
formerly unrecognized hazard, report new data on a known hazard, or present
information on hazard control.
Alerts, Special Hazard Reviews, Occupational Hazard Assessments, and Technical
Guidelines support and complement the other standards development activities
of the Institute. Their purpose is to assess the safety and health problems
associated with a given agent or hazard (e.g., the potential for injury or for
carcinogenic, mutagenic, or teratogenic effects) and to recommend appropriate
control and surveillance methods. Although these documents are not intended
to supplant the more comprehensive criteria documents, they are prepared to
assist OSHA and MSHA in the formulation of regulations.
In addition to these publications, NIOSH periodically presents testimony
before various Congressional committees and at OSHA and MSHA rulemaking
hearings.
A complete list of occupational safety and health issues for which NIOSH has
formal policies (e.g., recommendations for occupational exposure to chemical
and physical hazards, engineering controls, work practices, safety
considerations, etc.) can be found in NIOSH Recommendations for
Occupational Safety and Health: Compendium of Policy Documents and
Statements [DHHS (NIOSH) Publication No. 92-100].
HOW TO USE THIS POCKET GUIDE
The Pocket Guide has been designed to provide chemical-specific data to
supplement general industrial hygiene knowledge. To maximize the amount of
data provided in this limited space, abbreviations and codes have been used
extensively. These abbreviations and codes, which have been designed to
permit rapid comprehension by the regular user, are discussed for each column
in the following subsections.
Chemical Name and Structure/Formula, CAS and RTECS Numbers, and
DOT ID and Guide Numbers
Chemical Name and Structure/Formula - The chemical name found in
the OSHA General Industry Air Contaminants Standard (29 CFR 1910.1000) is
listed first. The chemical formula is also provided under the chemical name.
CAS and RTECS Numbers - The Chemical Abstracts Service (CAS) number,
in the format xxx-xx-x, is unique for each chemical and allows efficient
searching on computerized data bases. The NIOSH Registry of Toxic Effects
of Chemical Substances (RTECS) number, in the format ABxxxxxxx, may be
useful for obtaining additional toxicologic information on a specific
substance.
DOT ID and GUIDE Number - The U.S. Department of Transportation
(DOT) identification number and the corresponding guide number. Their format
is xxxx xxx. The Identification number (xxxx) indicates that the chemical is
regulated by DOT. The Guide number (xxx) refers to actions to be taken to
stabilize an emergency situation; this information can be found in the 2000 Emergency Response Guidebook (Office of Hazardous Materials
Training and Initiatives [DHM-50], Research and Special Programs
Administration, U.S. Department of Transportation, Washington, D.C.
20590-0001; for sale by the U.S. Government Printing Office, Superintendent of
Documents, Mail Stop: SSOP, Washington, D.C. 20402-9328). A page index for
all DOT ID numbers listed is included at the back of the Pocket Guide
to help the user locate a specific substance; please note however, that many
DOT numbers are NOT unique for specific substances.
Synonyms, Trade Names, and Conversion Factors
Common synonyms and trade names are listed alphabetically for each chemical.
Factors for the conversion of ppm (parts of vapor or gas per million parts of
contaminated air by volume) to mg/m3 (milligrams of vapor or gas
per cubic meter of contaminated air) at 25 °C and 1 atmosphere are listed
for chemicals with exposure limits expressed in ppm.
Exposure Limits
The NIOSH recommended exposure limits (RELs) are listed first in this column.
Unless noted otherwise, RELs are time-weighted average (TWA) concentrations
for up to a 10-hour workday during a 40-hour workweek. A short-term exposure
limit (STEL) is designated by "ST" preceding the value; unless noted
otherwise, the STEL is a 15-minute TWA exposure that should not be exceeded at
any time during a workday. A ceiling REL is designated by "C" preceding the
value; unless noted otherwise, the ceiling value should not be exceeded at any
time. Any substance that NIOSH considers to be a potential occupational
carcinogen is designated by the notation "Ca" see (Appendix A, which contains
a brief discussion of potential occupational carcinogens).
The OSHA permissible exposure limits (PELs), as found in Tables Z-1, Z-2, and
Z-3 of the OSHA General Industry Air Contaminants Standard (29 CFR 1910.1000),
that were effective on July 1, 1993* and which are currently
enforced by OSHA are listed next. [*Note: In July 1992, the 11th Circuit Court of Appeals in its decision in AFL-CIO v. OSHA, 965 F.2d 962 (11th Cir., 1992) vacated more protective PELs set by OSHA in 1989 for 212 substances, moving them back to PELs established in 1971. The appeals court also vacated new PELs for 164 substances that were not previously regulated. The substances for which OSHA PELs were vacated on June 30, 1993 are indicated by the symbol "†" following OSHA PEL in this column. A number of RELs are based on NIOSH concurrence with the data presented and the airborne exposure limits proposed in this rulemaking.] Unless noted otherwise,
PELs are TWA concentrations that must not be exceeded during any 8-hour
workshift of a 40-hour workweek. A STEL is designated by "ST" preceding the
value and is measured over a 15-minute period unless noted otherwise. OSHA
ceiling concentrations (designated by "C" preceding the value) must not be
exceeded during any part of the workday; if instantaneous monitoring is not
feasible, the ceiling must be assessed as a 15-minute TWA exposure. In
addition, there are a number of substances from Table Z-2 (e.g., beryllium,
ethylene dibromide, etc.) that have PEL ceiling values that
must not be exceeded except for specified excursions. For example, a "5-minute maximum
peak in any 2 hours" means that a 5-minute exposure above the ceiling value, but never
above the maximum peak, is allowed in any 2 hours during an 8-hour workday.
Appendix B contains a brief
discussion of substances regulated as carcinogens by OSHA.
Concentrations are given in ppm, mg/m3, mppcf (millions of
particles per cubic foot of air as determined from counting an impinger
sample), or fibers/cm3 (fibers per cubic centimeter). The "[skin]"
designation indicates the potential for dermal absorption; skin exposure
should be prevented as necessary through the use of good work practices and
gloves, coveralls, goggles, and other appropriate equipment. The "(total)"
designation indicates that the REL or PEL listed is for "total particulate"
versus the "(resp)" designation which refers to the "respirable fraction" of
the airborne particulate. Appendix C contains more detailed discussions of
the specific exposure limits for certain low-molecular-weight aldehydes,
asbestos, various dyes (benzidine-, o-tolidine-, and o-dianisidine-based),
carbon black, the various chromium compounds (chromic acid and chromates,
chromium(II) and chromium(III) compounds, and chromium metal), coal tar pitch
volatiles, coke oven emissions, cotton dust, lead, NIAX Catalyst ESN,
trichloroethylene, and tungsten carbide (cemented). Appendix D contains a
brief discussion of substances included in the Pocket Guide with no
established RELs at this time and Appendix F contains miscellaneous notes
regarding the OSHA PELs. Appendix G lists the OSHA PELs that were vacated on
June 30, 1993.]
IDLH
For the June 1994 Edition of the Pocket Guide, immediately dangerous to life or
health concentrations (IDLHs) were reviewed and, in many cases, were
revised and made more protective. As a consequence of the IDLH changes, many
of the respirator recommendations for these substances were also revised.
The criteria utilized to determine the adequacy of existing IDLH values were a
combination of those used during the Standards Completion Program and a newer
methodology developed by NIOSH. These "interim" criteria form a tiered
approach with acute human toxicity data being used preferentially, followed
next by acute animal inhalation toxicity data, and then finally by acute
animal oral toxicity data to determine an updated IDLH value. When relevant
acute toxicity data were insufficient or unavailable, the use of chronic
toxicity data or an analogy to a chemically similar substance was considered.
The criteria and information sources for both the original and revised IDLH
values are given in Documentation for Immediately Dangerous to Life and
Health Concentrations (IDLHs) (NTIS Publication No. PB-94-195047). NIOSH
is currently assessing the various uses of IDLHs and whether the original
criteria used to derive the IDLH values are valid or if other information or
criteria should be utilized. Based on this assessment, NIOSH will develop a
new strategy for revising the IDLH values currently listed, as well as for
developing new IDLH values for the more than 300 substances listed in the
Pocket Guide without IDLHs.
The definition of IDLH that was derived during the Standards Completion
Program was based on the Mine Safety and Health Administration (MSHA)
definition stipulated in 30 CFR 11.3(t). The purpose for establishing an IDLH
value in the Standards Completion Program was to ensure that a worker could
escape without injury or irreversible health effects from an IDLH exposure in
the event of the failure of respiratory protection equipment. The IDLH was
considered a maximum concentration above which only a highly reliable
breathing apparatus providing maximum worker protection was permitted. In
determining IDLH values, the ability of a worker to escape without loss of
life or irreversible health effects was considered along with severe eye or
respiratory irritation and other deleterious effects (e.g., disorientation or
incoordination) that could prevent escape. As a safety margin, the Standards
Completion Program IDLH values were based on the effects that might occur as a
consequence of a 30-minute exposure. However, the 30-minute period was NOT
meant to imply that workers should stay in the work environment any longer
than necessary, in fact, EVERY EFFORT SHOULD BE MADE TO EXIT IMMEDIATELY!
The current NIOSH definition for an IDLH exposure condition, as stipulated in
the NIOSH Respirator Decision Logic (DHHS [NIOSH] Publication No.
87-108, NTIS Publication No. PB-91-151183), is a condition "that poses a
threat of exposure to airborne contaminants when that exposure is likely to
cause death or immediate or delayed permanent adverse health effects or
prevent escape from such an environment." The purpose of establishing an IDLH
exposure concentration is to "ensure that the worker can escape from a given
contaminated environment in the event of failure of the respiratory protection
equipment." The NIOSH Respirator Decision Logic uses these IDLH values as one
of several respirator selection criteria. Under the NIOSH Respirator Decision Logic, the most protective respirators (e.g., a self-contained breathing
apparatus equipped with a full facepiece and operated in a pressure-demand or
other positive-pressure mode) would be selected for firefighting, exposure to
carcinogens, entry into oxygen-deficient atmospheres, in emergency situations,
during entry into an atmosphere that contains a substance at a concentration
greater than 2,000 times the NIOSH REL or OSHA PEL, and for entry into IDLH
atmospheres.
IDLH values are listed for over 380 substances. The notation "Ca" appears in
this column for all substances that NIOSH considers to be potential
occupational carcinogens. However, IDLH values that were originally
determined in the Standards Completion Program or were recently revised are
shown in brackets following the "Ca" designations. "10%LEL" indicates that
the IDLH was based on 10% of the lower explosive limit for safety
considerations even though the relevant toxicological data indicated that
irreversible health effects or impairment of escape existed only at higher
concentrations. "N.D." indicates that an IDLH has not as yet been determined.
Physical Description
This entry provides a brief description of the appearance and odor of each
substance. Notations are made as to whether a substance can be shipped as a
liquefied compressed gas or whether it has major use as a pesticide.
Chemical and Physical Properties
The following abbreviations are used for the chemical and physical properties
given for each substance. "NA" indicates that a property is not applicable,
and a question mark (?) indicates that it is unknown.
| MW | Molecular weight |
| BP | Boiling point at 1 atmosphere, °F |
| Sol | Solubility in water at 68 °F (unless a different temperature is noted), % by weight (i.e., g/100 ml) |
| Fl.P | Flash point (i.e., the temperature at which the liquid phase gives off enough vapor to flash when exposed to an external ignition source), closed cup (unless annotated "(oc)" for open cup), °F |
| IP | Ionization potential, eV (electron volts) [Ionization potentials are given as a guideline for the selection of photoionization detector lamps used in some direct-reading instruments.] |
| VP | Vapor pressure at 68 °F (unless a different temperature is noted), mm Hg; "approx" indicates approximately |
| MLT | Melting point for solids, °F |
| FRZ | Freezing point for liquids and gases, °F |
| UEL | Upper explosive (flammable) limit in air, % by volume (at room temperature unless otherwise noted) |
| LEL | Lower explosive (flammable) limit in air, % by volume (at room temperature unless otherwise noted) |
| MEC | Minimum explosive concentration, g/m3 (when available) |
| Sp.Gr | Specific gravity at 68 °F (unless a different temperature is noted) referenced to water at 39.2 °F (4 °C) |
| RGasD | Relative density of gases referenced to air = 1 (indicates how many times a gas is heavier than air at the same temperature) |
When possible, the flammability/combustibility of a substance was determined
and listed after the specific gravity. The following OSHA criteria (29 CFR
1910.106) were used to classify flammable or combustible liquids:
| Class IA flammable liquid | Fl.P. below 73 °F and BP below 100 °F. |
| Class IB flammable liquid | Fl.P. below 73 °F and BP at or above 100 °F. |
| Class IC flammable liquid | Fl.P. at or above 73 °F and below 100 °F. |
| Class II combustible liquid | Fl.P. at or above 100 °F and below 140 °F. |
| Class IIIA combustible liquid | Fl.P. at or above 140 °F and below 200 °F. |
| Class IIIB combustible liquid | Fl.P. at or above 200 °F. |
Incompatibilities and Reactivities
This entry lists important hazardous incompatibilities or reactivities of each
substance.
Measurement Methods
This entry provides a source (NIOSH or OSHA) and the method number for which a measurement method can be used to determine the exposure. Unless otherwise noted, the NIOSH methods are from the 4th edition of the
NIOSH Manual of Analytical Methods (DHHS [NIOSH] Publication No.
94-113). If a different
edition of the NIOSH Manual of Analytical Methods is cited, the
appropriate edition and, where applicable, the volume number would
be noted [e.g., II-4 (2nd edition, volume 4)]. The OSHA methods are from the OSHA web site, http://www.osha-slc.gov/dts/sltc/methods/. "None available" means that no method is available from the NIOSH or OSHA source.
Personal Protection and Sanitation
This column presents a summary of recommended practices for each toxic
substance. These recommendations supplement general work practices (e.g., no
eating, drinking, or smoking where chemicals are used). Table 3 explains the
codes used. Each category is described as follows:
| SKIN: | Recommends the need for personal protective clothing. |
| EYES: | Recommends the need for eye protection. |
| WASH SKIN: | Recommends when workers should wash the spilled chemical from the body in addition to normal washing (e.g., before eating). |
| REMOVE: | Advises workers when to remove clothing that has accidentally become wet or significantly contaminated. |
| CHANGE: | Recommends whether the routine changing of clothing is needed. |
| PROVIDE: | Recommends the need for eyewash fountains and/or quick drench facilities. |
First Aid
This entry lists emergency procedures for eye and skin contact, inhalation,
and ingestion of the toxic substance.
Respirator Recommendations
This entry provides a condensed table of allowable respirator use for those
substances for which IDLH values have been determined. NIOSH is currently
reevaluating the IDLH values, and as new or revised IDLH values are developed,
respirator selection recommendations will be incorporated into subsequent
editions of the Pocket Guide. In the interim no respirator
recommendations will be made for substances without IDLH values (these will be
noted by "To be added later").
NIOSH has developed a new set of regulations in 42 CFR 84 (also referred to as
"Part 84") for testing and certifying nonpowered, air-purifying,
particulate-filter respirators. The new Part 84 respirators have passed a
more demanding certification test than the old respirators (e.g.; dust; dust
and mist; dust, mist, and fume; spray paint; pesticide; etc.) certified under
30 CFR 11 (also referred to as "Part 11"). Under Part 84, NIOSH is allowing
manufacturers to continue selling and shipping Part 11 particulate filters as
NIOSH-certified until July 10, 1998. It is important to see the NIOSH
Guide to the Selection and Use of Particulate Respirators (DHHS [NIOSH]
Publication No. 96-101) for substitution of Part 84 respirators for Part 11
respirators.
The first line in the entry indicates whether the "NIOSH" or the "OSHA"
exposure limit is used on which to base the respirator recommendations. The
more protective limit between the NIOSH REL or the OSHA PEL is always used.
"NIOSH/OSHA" indicates that the limits are equivalent.
Each subsequent line lists a maximum use concentration (MUC) followed by the
classes of respirators, with their assigned protection factors (APFs), that
are acceptable for use up to the MUC. Individual respirator classes are
separated by diagonal lines (/). More protective respirators may be worn.
Emergency or planned entry into unknown concentrations or entry into IDLH
conditions are followed by the classes of respirators acceptable for these
conditions. "Escape" indicates that the respirators are to be used only for
escape purposes. For each MUC or condition this entry lists only those
respirators with the required APF and other use restrictions based on the
NIOSH Respirator Decision Logic.
In certain cases, the recommended respirators are annotated with the following
symbols as additonal information:
| * | Substance reported to cause eye irritation or damage; may require eye protection |
| £ | Substance causes eye irritation or damage; eye protection needed |
| ^ | If not present as a fume |
| ¿ | Only nonoxidizable sorbents allowed (not charcoal) |
| † | End of service life indicator (ESLI) required |
All respirators selected must be approved by NIOSH and MSHA under the
provisions of 30 CFR 11 or by NIOSH under 42 CFR 84. The current listing of
NIOSH/MSHA certified respirators can be found in the NIOSH Certified
Equipment List (DHHS [NIOSH] Publication No. 2001-139). A list of Part 84
respirators can be found on the NIOSH Home Page
(http://www.cdc.gov/niosh/) or obtained by calling 1-800-35-NIOSH.
A complete respiratory protection program must be implemented and must fulfill
all requirements of 29 CFR 1910.134. A respiratory protection program must
include a written standard operating procedure covering regular training,
fit-testing, fit-checking, periodic environmental monitoring, maintenance,
medical monitoring, inspection, cleaning, storage and periodic program
evaluation. Selection of a specific respirator within a given class of
recommended respirators depends on the particular situation; this choice
should be made only by a knowledgeable person. REMEMBER:
Air-purifying respirators will not protect users against oxygen-deficient
atmospheres, and they are not to be used in IDLH conditions. The only
respirators recommended for fire fighting are self-contained breathing
apparatuses that have full facepieces and are operated in a pressure-demand or
other positive-pressure modes. Additional information on the selection and
use of respirators can be found in the NIOSH Respirator Decision Logic
and the NIOSH Guide to Industrial Respiratory Protection (DHHS
[NIOSH] Publication No. 87-116).
Route of Health Hazard
This entry lists the toxicologically important routes of entry for each
substance and whether contact with the skin or eyes is potentially hazardous.
Symptoms
This entry lists the potential symptoms of exposure.
Target Organs
This entry lists the organs that are affected by exposure to each substance.