Vapor Pressure

Vapor Density

Each record in the NPG is assigned a number between 1 and 677 (the total number of records in the NPG).  This allows you to retrieve a specific record at any time.  The search example above actually retrieves the single record for Benzene.  Note that the field label, an, is required; otherwise the search will be performed across all the full text fields in the database and more hits will be obtained.

Using this field to get to a particular record is one of the fastest single substance retrieval methods.

This is one of the fields contained within the Citation list (CITN) - it is a unique identifier for the chemical substance.

This field lists emergency procedures for eye and skin contact, inhalation, and ingestion of the toxic substance.  Full translations of the original abbreviations are used.

Boiling points are given in degrees Fahrenheit at 1 atmosphere unless otherwise stated.  Sometimes, additional important information is present such as "decomposes" or "explodes".

As the data only usually contains temperatures, it is not particularly useful to search in and so no search example is given.

This field cites the parts of the body (for humans and/or animals) that are attacked by cancer.

This field contains the 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.

This entry provides a brief description of the appearance and odor of each substance including the physical state (solid, liquid or gas) of the substance in question.  For example: oily liquid, yellow solid, colorless crystals, etc..  Information is given as to whether a substance can be shipped as a liquefied compressed gas or whether it has major use as a pesticide.

The CPP field is displayed in records but is not searchable and contains the following text:

CHEMICAL AND PHYSICAL PROPERTIES CATEGORY (USE CODE ZCPP).

Its purpose is to act as a record section delimiter.  The Chemical and Physical Properties category (ZCPP) is associated with this message field.

This field contains specific gravity of the substance at 68°F with reference to water at 39.2°F (4°C).  If reported at a different temperature, this will be noted in the data.

As this data is usually numeric, it is not particularly useful to search in and so no search example is given.

The UN (United Nations) Number is a four-figure code used to identify hazardous chemicals and is used for identification of chemicals transported internationally by road, rail, sea and air.  In the UK this number is also called the "Substance Identification Number" or "SI Number".  The DOT (U.S. Department of Transportation) number, identical to the UN number, identifies the proper shipping name of hazardous wastes under 49 CFR 170.

The first part of this field 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).

Each category is described as follows (PPE = Personal Protective Equipment):

**SKIN PROTECTION** -> Recommends the need for personal protective clothing.
**EYE PROTECTION** -> Recommends the need for eye protection.
**SKIN CLEAN-UP** -> Recommends when workers should wash the spilled chemical from the body in addition to normal washing (e.g., before eating).
**CLOTHING/PPE REMOVAL** -> Advises workers when to remove clothing that has accidentally become wet or significantly contaminated.
**CLOTHING/PPE CHANGE** -> Recommends whether the routine changing of clothing is needed.
**PPE FACILITIES** -> Recommends the need for eyewash fountains and/or quick drench facilities.

The second part of this field provides information of allowable respirator use for those substances for which IDLH values have been determined and other substances.  NIOSH is currently re-evaluating 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 1995, NIOSH 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 [D] dust and mist [DM]; dust, mist, and fume [DMFu]; 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.  The Pocket Guide still refers to the Part 11 terminology (i.e., dust, mist, and fume) and its corresponding assigned protection factors (APFs) for nonpowered, air-purifying, particulate-filter respirators.  However, the Part 11 terminology will be updated as Part 84 respirator recommendations become available, and NIOSH will not continue to use Part 11 terminology in any new respirator recommendations. Thus, it is important to see Appendix B in the NIOSH Guide to the Selection and Use of Particulate Respirators (DHHS [NIOSH] Publication No. 96-101) for substitution of Part 84 filters when a properly selected Part 11 respirator is in use.  If a respirator is not currently in use, the Part 11 respirator and filter selection may be made using the APFs for the facepiece types for the chemical or substance of concern.

In January 1998, OSHA revised its respiratory protection standard, 29 CFR 1910.134.  Among the provisions in the revised standard is the requirement for an end-of-service-life indicator (ESLI) or a change schedule when air-purifying respirators with chemical cartridges or canisters are used for protection against gases and vapors [29 CFR 1910.134 (d)(3)(iii)].  In the Pocket Guide, air-purifying respirators (without ESLIs) for protection against gases and vapors are recommended only for chemicals with adequate warning properties, but now these respirators may be selected regardless of the warning properties.  The respirator recommendations, including those for carcinogens, have not been revised accordingly.

Where this data occurs, the first piece of information under the heading "RECOMMENDATIONS FOR RESPIRATOR SELECTION:" 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 and OSHA" indicates that the limits are equivalent.

Each subsequent paragraph lists a maximum use concentration (MUC - UP TO ...) followed by classes of respirators that are acceptable for use below the MUC.  More protective respirators may be worn.  Respirator information for "EMERGENCY OR PLANNED ENTRY INTO UNKNOWN CONCENTRATIONS OR IDLH CONDITIONS" follows.

"ESCAPE" indicates that the respirators are to be used only for escape purposes.  For each MUC or condition only those respirators with the required/assigned protection factor (APF) and other use restrictions based on the NIOSH Respirator Decision Logic are listed.

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. 2002-144).  A list of Part 84 respirators can be found on the NIOSH Home Page (http://www.cdc.gov/niosh/homepage.html) 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).

Where present, this field cites the lower explosive (flammable) limit in air, % by volume at room temperature unless otherwise noted, (LEL) and/or the upper explosive (flammable) limit in air, % by volume at room temperature unless otherwise noted, (UEL) or the minimum explosive concentration in g/m3.

The search example given will yield all those substances in the NPG which have a minimum explosive concentration.

The EXSR field is displayed in records but is not searchable and contains the following text:

EXPOSURE LIMITS CATEGORY (USE CODE ZEXS).

Its purpose is to act as a record section delimiter.  The Exposure Limits category (ZEXS) is associated with this message field.

When possible, the flammability/combustibility of a substance was determined and 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.

In the above Fl.P. means flash point.

This field, where it occurs, gives the flash point of the substance (i.e. the temperature, in degrees Fahrenheit, at which the liquid phase gives off enough vapor to flash when exposed to an external ignition source) as measured via the closed cup method (unless annotated "(o.c.)" or similar for the open cup method).

As the information given is mainly numeric data, it is not particularly useful to search in and so no search example is given.

This field contains the freezing point for liquids and gases in degrees Fahrenheit.  In many records, however, a melting point is given, preceded by the text "MLT: ".

As the information given is mainly numeric data, it is not particularly useful to search in and so no search example is given.

The Guide page number - normally 3 digits - refers to actions to be taken to stabilize an emergency situation; this information can be found in the 1996 North American 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).  The letter P following the Guide page number in some records identifies materials which present a polymerization hazard under certain conditions.  Sometimes more than one such number is given, usually for different forms of the substance.  In some records, the acronym n.o.s appears - this means not otherwise specified.

Please note that there is a newer version of North American Emergency Guidebook which is available elsewhere on CHEM-BANK and is known as ERG2000.

If this field is populated it will contain a URL link to International Chemical Safety Card, a copy of which is held on the NIOSH website.

In WinSPIRS you will need to cut and paste the link into your browser - in WebSPIRS just click on the URL link and the information will appear in a separate window.

The ID field is displayed in records but is not searchable and contains the following text:

SUBSTANCE IDENTIFICATION CATEGORY (USE CODE ZID).

Its purpose is to act as a record section delimiter.  The Substance Identification category (ZID) is associated with this message field.

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 - also at http://www.cdc.gov/niosh/idlh/idlh-1.html - see also http://www.cdc.gov/niosh/idlh/intridl4.html).  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 remaining 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 - see also http://www.cdc.gov/niosh/87-108.html), 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 (recommended exposure limit)  or OSHA PEL (permissible exposure limit), and for entry into IDLH atmospheres.

IDLH values are listed for nearly 400 substances and are given in either ppm or mg/m3.  The phrase 'Potential NIOSH Carcinogen' appears for those substances that NIOSH considers to be so, regardless of whether an IDLH value appears or not.  "10 percent 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.

Please also note that in many records links appear in this field to substance-specific IDLH documentation.  In WinSPIRS you will need to cut and paste the link into your browser - in WebSPIRS just click on the URL link and the IDLH documentation will appear in a separate window.

The first search example given above finds those substances which NIOSH has determined to be potential carcinogens.  The second example finds those records with additional substance-specific IDLH documentation available on the NIOSH website (see the previous paragraph).

This field, if present, gives the ionization potential in eV (electron volts).  Ionization potentials are given as a guideline for the selection of photoionization detector lamps used in some direct-reading instruments.

The MAM field is displayed in records but is not searchable and contains the following text:

MONITORING AND ANALYSIS METHODS CATEGORY (USE CODE ZMAM).

Its purpose is to act as a record section delimiter.  The Monitoring and Analysis Methods category (ZEXS) is associated with this message field.

This field provides a source (NIOSH or OSHA) and the method URL for which a measurement method can be used to determine the exposure.

The NIOSH methods are taken from the NIOSH Manual of Analytical Methods (NMAM (R)), 4th ed. DHHS (NIOSH) Publication 94-113 (August, 1994), http://www.cdc.gov/niosh/nmam/nmampub.html.

The OSHA methods are from the OSHA web site, http://www.osha-slc.gov/dts/sltc/methods/.

In WinSPIRS you will need to cut and paste the link into your browser - in WebSPIRS just click on the URL link and the method information will appear in a separate window.

This field contains URLs pointing to pages containing specific medical tests published in the literature for OSHA regulated substances.

In WinSPIRS you will need to cut and paste the link into your browser - in WebSPIRS just click on the URL link and the medical test information will appear in a separate window.  There is medical test information for over 250 substances - the search example reveals them all.

This field occurs in most records - sometimes some explanatory text appears if an exact molecular weight cannot be given.

As the information given is mainly numeric data, it is not particularly useful to search in and so no search example is given.

The NIOSH recommended exposure limits (RELs) are listed in this field.  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 "STEL" 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 "CEIL" preceding the value; unless noted otherwise, the ceiling value should not be exceeded at any time.

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.

This field will contain the text of Appendix A of the printed guide (also at http://www.cdc.gov/niosh/npg/nengapdx.html#a) for any substance that NIOSH considers to be a potential occupational carcinogen - see text directly below in italics within quotation marks.

"Appendix A

NIOSH Potential Occupational Carcinogens

NEW POLICY

For the past 20 plus years, NIOSH has subscribed to a carcinogen policy that was published in 1976 by Edward J. Fairchild, II, Associate Director for Cincinnati Operations, which called for "no detectable exposure levels for proven carcinogenic substances" (Annals of the New York Academy of Sciences, 271:200-207, 1976).  This was in response to a generic OSHA rulemaking on carcinogens.  Because of advances in science and in approaches to risk assessment and risk management, NIOSH has adopted a more inclusive policy.  NIOSH recommended exposure limits (RELs) will be based on risk evaluations using human or animal health effects data, and on an assessment of what levels can be feasibly achieved by engineering controls and measured by analytical techniques.  To the extent feasible, NIOSH will project not only a no-effect exposure, but also exposure levels at which there may be residual risks.  This policy applies to all workplace hazards, including carcinogens, and is responsive to Section 20(a)(3) of the Occupational Safety and Health Act of 1970,  which charges NIOSH to ". . .describe exposure levels that are safe for various periods of employment, including but not limited to the exposure levels at which no employee will suffer impaired health or functional capacities or diminished life expectancy as a result of his work experience."

The effect of this new policy will be the development, whenever possible, of quantitative RELs that are based on human and/or animal data, as well as on the consideration of technological feasibility for controlling workplace exposures to the REL.  Under the old policy, RELs for most carcinogens were non-quantitative values labeled "lowest feasible concentration (LFC)."  [Note:  There are a few exceptions to LFC RELs for carcinogens (e.g., RELs for asbestos, formaldehyde, benzene, and ethylene oxide are quantitative values based primarily on analytical limits of detection or technological feasibility).  Also, in 1989, NIOSH adopted several quantitative RELs for carcinogens from OSHA's permissible exposure limit (PEL) update.]

Under the new policy, NIOSH will also recommend the complete range of respirators (as determined by the NIOSH Respirator Decision Logic) for carcinogens with quantitative RELs.  In this way, respirators will be consistently recommended regardless of whether a substance is a carcinogen or a non-carcinogen.

OLD POLICY

In the past, NIOSH identified numerous substances that should be treated as potential occupational carcinogens even though OSHA might not have identified them as such.  In determining their carcinogenicity, NIOSH used the OSHA classification outlined in 29 CFR 1990.103, which states in part:

"Potential occupational carcinogen means any substance, or combination or mixture of substances, which causes an increased incidence of benign and/or malignant neoplasms, or a substantial decrease in the latency period between exposure and onset of neoplasms in humans or in one or more experimental mammalian species as the result of any oral, respiratory or dermal exposure, or any other exposure which results in the induction of tumors at a site other than the site of administration.  This definition also includes any substance which is metabolized into one or more potential occupational carcinogens by mammals."

When thresholds for carcinogens that would protect 100 percent of the population had not been identified, NIOSH usually recommended that occupational exposures to carcinogens be limited to the lowest feasible concentration.  To ensure maximum protection from carcinogens through the use of respiratory protection, NIOSH also recommended that only the most reliable and protective respirators be used.  These respirators include (1) a self-contained breathing apparatus (SCBA) that has a full facepiece and is operated in a positive-pressure mode, or (2) a supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary SCBA operated in a pressure-demand or other positive-pressure mode.

RECOMMENDATIONS TO BE REVISED

The RELs and respirator recommendations for carcinogens listed in this edition of the Pocket Guide still reflect the old policy. Changes in the RELs and respirator recommendations that reflect the new policy will be included in future editions."

Some records contain the text of Appendix C which details 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).  Please consult the individual records for the appropriate texts (see the first search example given above).

Appendix D contains a brief discussion of substances included in the Pocket Guide with no established RELs at this time - see text directly below in italics within quotation marks.

"Appendix D

Substances With No Established RELs

After reviewing available published literature, NIOSH provided comments to OSHA on August 1, 1988, regarding the "Proposed Rule on Air Contaminants" (29 CFR 1910, Docket No. H-020).  In these comments, NIOSH questioned whether the PELs proposed for the following substances included in the Pocket Guide were adequate to protect workers from recognized health hazards: acetylene tetrabromide, chlorobenzene, coal dust (<5 percent SiO2), coal dust (>=5 percent SiO2), ethyl bromide, ethylene glycol, ethyl ether, fenthion, furfural, 2-isopropoxyethanol, isopropyl acetate, isopropylamine, manganese tetroxide (as Mn), molybdenum (soluble compounds as Mo), nitromethane, m-toluidine, and triethylamine.  At that time, NIOSH also conducted a limited evaluation of the literature and concluded that the documentation cited by OSHA was inadequate to support the proposed PELs of 10 mg/m3 for alpha-alumina, benomyl, emery, glycerine (mist), graphite (synthetic), magnesium oxide fume, molybdenum (insoluble compounds as Mo), particulates not otherwise regulated, picloram, and rouge."

See also the OSHA Exposure Limits field.

Contains additional information about the substance, typically its use or references to other pertinent records.  Note the use of truncation in the search example - this will yield hits on 'product', 'products', 'production', etc.

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 in this field.  [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.  A number of RELs (recommended exposure limits) 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 "CEIL" 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 (time-weighted average) 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.

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.

Appendix B contains a brief discussion of substances regulated as carcinogens by OSHA - see text directly below in italics within quotation marks.

"Appendix B

Thirteen OSHA-Regulated Carcinogens

Without establishing PELs, OSHA promulgated standards in 1974 to regulate the industrial use of 13 chemicals identified as potential occupational carcinogens (2-acetylaminofluorene, 4-aminodiphenyl, benzidine, bis-chloromethyl ether, 3,3'-dichlorobenzidine, 4-dimethylaminoazobenzene, ethyleneimine, methyl chloromethyl ether, alpha-naphthylamine, beta-naphthylamine, 4-nitrobiphenyl, N-nitrosodimethylamine, and beta-propiolactone).  Exposures of workers to these 13 chemicals are to be controlled through the required use of engineering controls, work practices, and personal protective equipment, including respirators. See 29 CFR 1910.1003-1910.1016 for specific details of these requirements.

Respirator selections in the Pocket Guide are based on NIOSH policy, which considers the 13 chemicals to be potential occupational carcinogens."

Some records contain the text of Appendix C which details 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).  Please consult the individual records for the appropriate texts.

Appendix F contains miscellaneous notes regarding the OSHA PELs for benzene - see text directly below in italics within quotation marks.

"Appendix F

The final Benzene standard in 1910.1028 applies to all occupational exposures to benzene except some subsegments of industry where exposures are consistently under the action level (i.e., distribution and sales of fuels, sealed containers and pipelines, coke production, oil and gas drilling and production, natural gas processing, and the percentage exclusion for liquid mixtures); for the excepted subsegments, the benzene limits in Table Z-2 apply (i.e., an 8-hour TWA of 10 ppm, an acceptable ceiling of 25 ppm, and 50 ppm for a maximum duration of 10 minutes as an acceptable maximum peak above the acceptable ceiling)."

See also the NIOSH Recommended Exposure Limits field.

The prime name of each substance is the chemical name found in the OSHA General Industry Air Contaminants Standard (29 CFR 1910.1000).

In many cases names have been hyphenated.  That is to say that all space characters in the name have been changed to hyphens and a terminal hyphen added.  Where this occurs and given the way SPIRS works, this means that the whole name appears in the index in hyphenated form together with each individual term making up the name.  The hyphenation and terminal hyphen acts as a device to indicate that the term does indeed come from the prime name or synonym field as opposed to other free text fields where the name will not, in general, be hyphenated in this way.  There is another important reason for adding a terminal hyphen - to aid focussed retrieval.  For example, the search benzene- in pn retrieves only the one record for the substance benzene, while benzene in pn retrieves all records containing the word 'benzene' in the PN field.  Similarly, ethyl-ether- in pn retrieves only the single record for ethyl ether, while ethyl ether in pn retrieves any record with those two words adjacent to each other in the PN field.  Whilst this device does not always work, it will always reduce the number of irrelevant records retrieved, in some cases dramatically.

As a general rule, hyphenation is not attempted in names which contain 'natural breaks' (such as parentheses, curly braces, brackets, slash characters etc.) or characters other than alphanumerics, commas, hyphens or spaces or names which are over 90 characters long.

Each word that appears in the PN field is searchable separately.  All parts of common and chemical names, including parent, substituents, modifiers, and locants are individually or collectively searchable, as in the above examples.

It is strongly recommended that you employ the technique of lateral searching when searching for long, complex names or parts of names from the records display area or free text index OR enclose the name or part-name in quotation marks.  See the section on indexable characters and searching for more useful information.

This field occurs in every NPG record.  If you unsure whether the name you intend you use is the prime name, it is best to search on the Name Fragments field which searches both this and the Synonyms field simultaneously.

This is one of the fields contained within the Citation list (CITN).

This entry lists important hazardous incompatibilities or reactivities of each substance.

Note the use of parentheses in the search example.  Typing moisture or water in reac will actually result in the search moisture or (water in reac) which is not the same and which yields different results as the search on moisture is NOT confined to the reac field alone.

The CAS Registry number is a numeric designation assigned by the Chemical Abstracts Service of the American Chemical Society that uniquely identifies a specific chemical compound, regardless of the name or nomenclature system used.

The number is always expressed in a hyphenated format with any leading zeroes omitted.  When searching in the RN field, include the hyphens; truncation and wildcards can be used as well (see the first search above) as sometimes similar CAS numbers refer to similar chemicals.  You can also omit the field label as the data is also indexed as free text.  Occasionally, descriptive text, usually relating to the form of the substance is included, to qualify the CAS number.

Using the CAS number is one of the fastest ways to get to a particular record.  CAS numbers exist in over 95% of NPG records.

This is one of the fields contained within the Citation list (CITN).

The NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) is a large database (over 150,000 records) developed by NIOSH containing toxicological information about chemical substances.  It is included in the CHEM-BANK compendium.

The RTECS number is assigned by NIOSH for new substances entering the database.

Each record in RTECS is assigned a unique Accession Number made up of 9 characters, the first two of which are alphabetic and the remainder numeric.  This allows you to retrieve a specific record at any time.  The first search example above actually retrieves the single record for Benzene.

Each number varies directly with the alphabetic sequence of the name, so that toluene, for example, has a higher number than benzene and the identifier is assigned alphabetically and numerically to each RTECS substance.  It is not intentionally related to the compound's toxicity or structure, although compounds with alphabetically similar names and, in some cases therefore, similar structures are grouped together.

The second search example given above finds all compounds containing zinc or zirconium in which these metals have been used to classify the substance.  Using RTECS numbers (as with CAS numbers (RN)) is particularly useful in narrowing down a search.

Using this field to get to a particular record is one of the fastest single substance retrieval methods.

This is one of the fields contained within the Citation list (CITN) - it is a unique identifier for the chemical substance.

The SAFE field is displayed in records but is not searchable and contains the following text:

SAFETY AND HANDLING CATEGORY (USE CODE ZSAF).

Its purpose is to act as a record section delimiter.  The Safety and Handling category (ZSAF) is associated with this message field.

This field lists the toxicologically important routes of entry for the substance in question and whether contact with the skin or eyes is potentially hazardous as well as the potential symptoms of exposure.

This field contains information concerning the solubility in water at 68 F (unless a different temperature is noted), % by weight (i.e., g/100 ml).  Sometimes a short phrase or word appears such as 'insoluble' or 'miscible'.

In nearly all cases that this field occurs, the character string depicts the structural formula (as opposed to chemical/molecular formula designating the elemental composition.

Double bonds are indicated by an equals (=) sign on display.  However, this character should be omitted from the search phrase (see the third search example for vinyl chloride).

This is one of the fields contained within the Citation list (CITN)

Common synonyms and trade names are listed alphabetically for each chemical in nearly all NPG records.  Please refer to the Prime Name field for details regarding hyphenation and presentation.  It is usually best to search for names via the Name Fragments field.

This is one of the fields contained within the Citation list (CITN)

This field lists the organs that are affected by exposure to the substance in question.  The first search example will yield results on 'bone', 'blood' and 'bladder', for example.

The TOXB field is displayed in records but is not searchable and contains the following text:

TOXICITY/BIOMEDICAL EFFECTS CATEGORY (USE CODE ZTOB).

Its purpose is to act as a record section delimiter.  The Toxicity/Biomedical Effects category (ZTOB) is associated with this message field.

This field cites the vapor pressure at 68°F unless otherwise stated.  The data is mostly given in mm Hg (millimetres of mercury) but also in atm (atmospheres).

As the information given is mainly numeric data, it is not particularly useful to search in and so no search example is given.

This field contains the relative density of the gas with reference to air (which has a value of 1).  The value indicates how many times a gas is heavier than air at the same temperature).

As the information given is mainly numeric data, it is not particularly useful to search in and so no search example is given.

The ZCPP category combines the following fields so that you can search, show, download or print them simultaneously:

Color/Form  (COFO)
Boiling Point  (BP)
Freezing Point  (FP)
Molecular Weight  (MW)
Specific Gravity  (DEN)
Solubility in Water  (SOL)
Vapor Density  (VAPD)
Vapor Pressure  (VAP)
Additional Notes  (NT)

The ZEXS category combines the following fields so that you can search, show, download or print them simultaneously:

Immediately Dangerous to Life or Health  (IDLH)
OSHA Exposure Limits  (OSHA)
NIOSH Exposure Limits  (NREC)
Conversion Factor  (CF)

The ZID category combines the following fields so that you can search, show, download or print them simultaneously:

Prime Name of Substance  (PN)
Synonyms  (SY)
CAS Registry Number  (RN)
Chemical Structure  (ST)
RTECS Number  (RTEC)
DOT (Department of Transportation) ID  (DOT)
North American Emergency Response Guide Page Number  (GP)
International Chemical Safety Card  (ICSC)

The ZMAM category combines the following fields so that you can search, show, download or print them simultaneously:

Measurement Methods  (MM)
Medical Tests  (MT)

The ZNF header combines the following fields so that you can search, show, download or print them simultaneously:

Prime Name of Substance  (PN)
Synonyms  (SY)

You should use this field to search for chemical names unless you are sure that the name that you are using is either in the PN or SY field.

The ZSAF category combines the following fields so that you can search, show, download or print them simultaneously:

Flammability Class  (FC)
Flash Point  (FLPT)
Explosive Limits  (EXPL)
Ionization Potential  (IP)
Incompatibilities and Reactivities  (REAC)
Personal Protection and Sanitation  (EQUP)

The ZTOB category combines the following fields so that you can search, show, download or print them simultaneously:

Cancer Site  (CARC)
Treatment of Exposure/First Aid  (ANTR)
Routes/Symptoms of Exposure  (SERI)
Target Organs  (TARG)

The Citation is a subset of fields consisting of the following fields:

NIOSH Pocket Guide Number  (AN)
Prime Name of Substance  (PN)
Synonyms  (SY)
CAS Registry Number  (RN)
Chemical Structure  (ST)

The Citation serves as an easy way to display, print, or save only these fields for a set of records.

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