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account with the company. I'm not sure about the US, but here in NZ discounts
can halve the price of most chemicals.
 
If you are intending to acquire a wide range of chemicals over time, an 
account may be a good idea, however remember that you may then be subject to 
inspection visits by regulators if you purchase certain chemicals. Most 
government and corporate organisations and laboratories also have policies 
of not supplying unknown individuals with *any* chemical.  Some chemical 
suppliers are also accessible via the Internet ( refer Section 7.10 )

9.4  Where can I purchase laboratory equipment? 

As with chemicals, simple laboratory equipment can be purchased from the
suppliers of home chemistry sets. Some government and state authorities
require certain equipment ( eg stills ) to be registered, especially if it
can be used to produce illegal substances. Most larger suppliers may 
require an account, but often specialist supplies can be purchased from
hobby shops such as home brew kit suppliers. Once again the FAQ of
relevant newsgroups ( such as alt.drugs and rec.pyrotechnics ) may provide
the names of suppliers, as can trade directories and the Yellow Pages.
Cole Palmer and Fisher offer free comprehensive catalogues that identify 
what is available. Some equipment suppliers are accessible via the Internet 
( refer Section 7.11 ).

9.5  What reference texts should I search first? 

If you require basic physical information about a chemical then many 
chemical suppliers catalogues also include common properties - such as 
boiling point, melting point, density, and flash point. Aldrich, Merck, 
and Lancaster provide information on organic chemicals, and Sigma covers 
biochemicals. Chemical catalogues also often provide cross references to the 
Chemical Abstracts Registry Numbers, the Merck Index, spectral libraries, 
safety, and preparation information. The actual product purity may limit the
accuracy of the data, and more accurate information could be available
in the Rubber Handbook or Merck Index. As catalogues are usually free on 
request ( Aldrich catalogue is also available on disk as a searchable 
database for $25 ), they are an excellent initial information source that 
will often direct you to appropriate reference texts. You may be able to
acquire an older edition by asking your chemistry teacher or chemical
storeroom supervisor.

Depending on the type of chemical information required, some specialist
reference texts may be required, but there are several texts that are common 
to most fields of chemistry. These are usually found in the reference 
section of most public and technical libraries and, because they are often 
heavily discounted for students, many chemists have copies of several of 
them. If your library does not have them, ask some of your teachers for 
access to their personal copy. 

Many of these texts are now also available on CD-ROM, usually at a slightly 
lower cost than the hardcopy, however the Merck Index is an exception where 
the CD-ROM version costs significantly more than the hardcopy. The Merck 
Index is an excellent starting point for information on organic chemicals 
used in the agricultural, biochemical, chemical, and pharmaceutical 
industries. It is usually available, along with the Rubber Handbook, in the
reference section of libraries. Don't expect a $7,000 encyclopedia set like 
Kirk Othmer to be freely available over the Internet, or available on 
CD-ROM for $100 :-). I have also marked those that are commercially 
available through online services with an asterisk.

For more detailed aspects of individual compounds, common texts include:- 

CRC Handbook of Chemistry & Physics  ( aka Rubber Handbook ) [7]
  - tabulations of diverse chemical and physical properties.
  - start here for physical data with minimal description.
The Merck Index * [8]
  - brief monographs on most common organic chemicals, especially those 
     used in the chemical, biochemical, and pharmaceutical industries.
  - excellent source for physical and physiological properties, common 
     names, and CAS RN.
  - monographs point to more descriptive sources.
  - available on CD-ROM, but the hardcopy version is much cheaper.
Lange's Handbook of Chemistry [9]
  - tabulations of chemical properties.
Hawley's Condensed Chemical Dictionary  [10]
  - very brief monographs on a wide range of common industrial chemicals.
  - very good starting point to ascertain physical properties of both
     inorganic and organic chemicals used in commerce.
  - Available on CD-ROM
Tables of Physical and Chemical Constants ( aka Kaye and Laby ) [11]
  - tabulations of constants, often not in the Rubber Handbook   
The Chemical Technicians' Ready Reference Handbook [12]
  - tabulations of various common chemicals and materials.
The Matheson Gas Data Book [13]
  - tabulations of properties of a diverse range of gases 
  
There are several good general "science" texts that provide basic coverage
of aspects of chemistry, eg the concise version of the McGraw Hill 
Encyclopedia of Science and Technology [14] or Van Nostrand's Scientific
Encyclopedia [15]. There are also several single volume chemistry books 
that provide brief monographs covering diverse aspects of chemistry, such as 
the McGraw Hill Encyclopedia of Chemistry [16]. These texts are often found 
in the reference sections of general libraries.

The next source is usually the encyclopedia sets that are also found in the
reference section of general libraries. There are some general ones that 
cover all fields of science, and often have annual updates. An example is 
the 20 volume McGraw Hill Encyclopedia of Science and Technology, available
in hardcopy or CD-ROM versions [17].

For more detailed, but still with general coverage, there are at least two 
popular large multi-volume chemistry encyclopedias. One, or both, of these 
is usually found in the reference sections of technical and large public
libraries. These have become the standard first point of reference for 
information on properties, production, and applications of industrial 
chemicals.

Kirk Othmer Encyclopedia of Chemical Technology - 4th edition * [18]
  - excellent 27 volume set 
  - extensive monographs on chemical families and processes.
  - start here if you wish to obtain up-to-date, easy-to-read, comprehensive 
    technical information on an amazingly diverse range of chemistry. 
  ( available in hardcopy ($324/volume, around $7,000/set), online, on 
    CD-ROM, and as a greatly-abridged concise volume (3rd Edition = $110)

Ullmann's Encyclopedia of Industrial Chemistry - 5th edition [19]
  - excellent translation from the original German edition. 
  - extensive monographs on common industrial processes 
  - the style is different to Kirk Othmer in that information is not so well
    integrated into the monograph, but often contains more hard information
    and good reviews of specific topics.
  ( In 1997 the fifth edition was made available on CD-ROM, with the sixth
    edition was started in 1998, with each CD holding the equivalent of
    three printed volumes. The full book/CD-ROM sixth edition will cost 
    around $14,000 )

There are also the very large multi-volume sets of specialised chemical
information that are mainly only found in institutions that have a strong 
chemistry or chemical engineering component, such as: 

Beilstein * [20] 
  - provides detailed monographs of most organic chemicals, covering
    preparation, properties and structure.
Gmelin [21]
  - provides detailed information on most elements and inorganic chemicals
Heilbron * [22]
  - provides short monographs of many organic compounds, mainly listing
    properties and references to preparations. An excellent way to 
    quickly find information on chemicals.
McKetta - Encyclopedia of Chemical Processing and Design [23]
  - extensive monographs containing technical data on chemical processes.
Encyclopedia of Polymer Science and Engineering - 2nd edition * [24]
  ( available in hardcopy, online, and in a greatly-abridged concise volume )
  - detailed monographs on common polymers and processes
Thorpe's Dictionary of Applied Chemistry [25]
  - getting old, but *still* contains lots of excellent information on the
    properties and industrial applications of chemicals 
  - is very useful for historical information on how a product developed.

For more specialised references, refer to the appropriate section of this
FAQ, however I will list a few texts covering general laboratory techniques
not mentioned elsewhere. If your local bookshop does not carry specialist
technical books, many are also available from appropriate chemical and 
equipment suppliers, such as Aldrich-Sigma and Supelco.
Vacuum = High Vacuum Techniques for Chemical Syntheses and Measurements [26].
       = High Vacuum Techniques [27]
Pipework = Swagelok Tube Fitting and Installation Manual [28]
Thermocouples = Thermocouples: Theory and Practice [29]
( The Omega catalogues are also a good source of practical information
  on a wide range of temperature, flow and pressure sensors ) 
Many of the laboratory safety texts also include sections on design and
management of laboratories.

9.6  Where can I find physical and spectral properties of chemicals?

Some chemical suppliers catalogues ( eg Aldrich [5] ), also include common
properties such as boiling point, melting point, density, flash point.
Most will provide a catalogue free on request, but it is often easier to 
obtain an obsolete edition from your institution, as they usually just throw 
them out. The most information is often in catalogues from international 
laboratory chemical suppliers ( eg J.T.Baker [6], Merck [30], Rhone-Poulenc 
[31] ), and specialist organic chemical suppliers ( eg Aldrich [5], 
Sigma [32], Janssen [33], Lancaster [34] ), however it should be remembered
that the product purity will affect the value reported, and that more
accurate values may be available in references such as the Merck Index or
Rubber Handbook. 

Once you have checked the catalogues, and checked the standard texts above, 
then more specialised compilations should be checked. For spectral 
properties, there are several large compilations of detailed spectral
properties, including infra-red [35-37], NMR [38-40], and mass-spec [41,42]. 
These are usually located near the instruments, rather than in the library,
however the NIST IR and mass spectral libraries are accessible via the WWW 
( refer Section 7.2 ).

Most transportation safety compilations and MSDS also list common physical
properties, as do the most of the encyclopedia sets ( refer Section 9.5 ).
More specialised information is usually found in specialist books or
journals, such as the Journal of Chemical and Engineering Data.

9.7  Where can I find production data for commercial chemicals 

Both Kirk Othmer and Ullmann tabulate production data, and identify
major manufacturers, and more recent information is found in monographs 
in CMR. C&EN also tabulates production data for the major industrial 
chemicals and publishes an annual listing of the top 50 chemicals. Lists of 
manufacturers of chemicals are found in compilations such as Chemical 
Sources [2,3] and trade directories. There are also industry organisations
such as the Chemical Manufacturers Association that maintain records of
production. Specialist industry journals usually provide annual surveys
of production and capacity. Government departments ( often the Dept. of
"Trade & Industry" or "Commerce" ) also compile national production
statistics. 

9.8  Where can I find the composition of a proprietary chemical?

If it has been patented, the composition will be detailed in the patent,
and any local patent agent should be able to locate and obtain a copy. 
Transportation regulations usually require manufacturers to list components,
consequently examination of the MSDS often provides an indication of major
components, some of which are likely to just be the solvent. There are also
compilations of chemical tradenames that may also indicate what the major
components in a proprietary chemical. Hawley, Gardner, Industrial 
Chemical Thesaurus [43], Encyclopedia of Industrial Chemical Additives [44],
and the Chemical Tradenames Dictionary [45] are good starting points. 

In some countries only the "active" or "toxic" ingredients have to be 
disclosed, consequently chemical analysis would have to be undertaken. 
Another technique is to look for equivalent formulations - to ascertain what 
ingredients are typically used, and the multi-volume Chemical Formulary [46] 
is one of the best sources if you can not justify a patent search. 

9.9  Where can I find out about the history of Chemistry? 

There is a soc.history.science Usenet group that is very knowledgeable and
active, and includes individual events in the history of chemistry. There
are usually several overview books on the history of chemistry in most school 
and public libraries, and example is "The History of Chemistry" by J.Hudson
[47]. There are also several outstanding biographies of famous chemists, and 
many chemical societies and chemical firms have commissioned books on 
specific aspects of chemistry history. The Journal of Chemical Education 
often has articles on specific historical aspects of chemistry.   

9.10 Where can I find out about the discovery of an element?

The Rubber Handbook has a monograph on each element, including a brief
discussion of the discovery. "Chemistry of the Elements" by Greenwood and 
Earnshaw [48], and "The Elements" by Emsley [49], also provide good 
discussions, and Gmelin provides a fairly comprehensive discussion of 
discovery of each element. In each of the above, the discovery of each 
element is taken in isolation. The best general overview that provides a 
cohesive framework explaining the overall progression of discoveries, is 
"Discovery of the Elements" by Weeks [50], and it should be available in most 
libraries. For the more recent elements, there usually are brief reports and 
discussions in C&EN and the Journal of Chemical Education.  

9.11 What inspirational books about chemistry should I read?

Do they exist :-)?. You could try "The Chemical Bond: Structure and Dynamics"
edited by A.Zewail [51]. It contains articles by several Nobel Laureates.

If you want to be entertained, and only have time for a short read, try the
"Chemistry in the Next Century" [52] article in Industrial and Engineering
Chemistry written in May 1935 by Thomas Midgley, Jr.. He was responsible for 
the discovery and development of CFCs and alkyl lead octane enhancers for 
gasoline - two chemical developments that became so pervasive and useful 
that their use resulted in unintentional environmental pollution. 
For a brief story about their discovery, try "Midgley - Saint or Serpent" 
[53] in Chemtech. It confirms that old saying " Luck is when preparation
meets opportunity ". 

------------------------------ 

Subject: 10. Traditional Laboratory and Chemical Safety Information Sources
 
10.1  Where can I find Material Safety Data Sheets? 

Most suppliers of chemicals will provide a MSDS on request if you are a
customer. Several major chemical suppliers have combined their own MSDS 
sheets and issued major compilations, eg Sigma-Aldrich [1] ( available on 
CD-ROM or Magnetic Tape for $1,650), which may be available in the
library. If a librarian can not locate the MSDS database, then try the 
Health and Safety Officer, who should know where to find MSDS. Larger
organisations often purchase a compilation and make it available on a 
computer network for in-house use. The US Department of Defence CD-ROM
of approximately 200,000 MSDS is available for approximately $100. 

10.2  Where can I find hazard information for a chemical? 

Chemical suppliers usually include common hazard information in their
catalogues. Merck and Hawley also list some information. Large compilations 
include Sax, Fire Protection Guide to Hazardous Materials [2],
Sigma-Aldrich Library of Chemical Safety Data [3], CRC Handbook of
Laboratory Safety [4], and Hazards in the Chemical Laboratory [5]. It is very 
important to realise that hazard information is frequently updated, and so 
information should be complemented with an online search of safety databases. 

If the chemical is already being used at your site, it is probable that the 
Safety Officer or Laboratory Manager already have the required information. 
The Handbook of Reactive Chemical Hazards [6], can be used to check for
possible hazardous reactions. Highly toxic, radioactive, and carcinogenic 
compounds require special precautions, and the Safety Officer or Laboratory 
Manager should be able to provide the appropriate resources to ascertain if 
the compound can be handled safely.

10.3  Where can I find detailed safety & toxicity data? 

The very first question you should ask is, "Am I qualified to assess
the data?". If the answer is no, then your best option is to locate somebody
who is. This can be a Health and Safety Officer, staff of an appropriate
government organisation (eg OSHA, NIOSH ), or a specialist consultant.
Most institutions have a policy of ensuring workers are given sufficient 
information about hazards to ensure they can make an informed decision.

There are several major compilations that are usually found in libraries, 
including RTECS, Sax, and the three-volume Sigma-Aldrich Library of
Regulatory and Safety Data [7]. In general, because safety information can 
become obsolete rapidly, these should only be used as an introductory guide, 
and they should be complemented with either an on-line search or consultation
with 
an expert. Detailed information for unusual chemicals is often difficult to
locate in the published literature, and may only be available to qualified
professionals in the health and safety fields. Sometimes the toxicity has to
be inferred from published information on related compounds, and such 
assessments should always be performed by experts. 
   
10.3  Where can I find occupational exposure limits? 

There are several organisations responsible for establishing the
occupational exposure limits. The values used most extensively in industry, 
but also the most controversial, are those of the ACGIH. Their TLVs and 
Biological Exposure Indices [8] have been used in many countries as initial 
guidelines until relevant local expertise can assess their suitability. 
They are also misused, despite the clear warnings in the front of the 
booklet. 

The US Government also has Permissible Exposures Limits set by the Dept. of 
Labor Occupational Safety and Health Administration, and Recommended
Exposure Limits set by the US National Institute for Occupational Safety and
Health. The Deutsche Forschungsgemeinschaff Maximum Concentrations in the
Workplace are often also used. The ACGIH publishes an excellent compilation
of all these limits [9], thus facilitating a review of how experts perceive
the occupational hazards. The International Labour Office in Geneva 
publishes a comprehensive " Encyclopedia of Occupational Health and Safety "
which also covers chemicals [10].
  
10.5  What is the most poisonous compound? 

" All substances are poisons. There is not one that is not a poison. The 
  correct dose differentiates a poison and a remedy". (Paracelsus 1493-1541)

The McGraw Hill Encyclopedia of Science and Technology [11] lists the 
following table:

"Approximate Median Lethal Doses of Some Toxins per kg of Bodyweight"
Toxin                          Dose                Test Animal
tetanus                     1 nanogram           mouse, probably human
botulinal neurotoxin        1 nanogram           mouse, human
shigella                    1 nanogram          monkey, human
shigella                    1 microgram             mouse
ricin                       1 microgram             human
diphtheria                100 nanograms             human
diphtheria                1.6 milligrams            mouse

Ricin is a toxin lectin and hemagglutinin isolated from the castor bean.
Merck reports the lethal dose in mice as 1 microgram of ricin D nitrogen 
(ip) per kg, and that ricin molecular weight is about 65,000. Ricin has 
been shown to contain four lectins, of which the RCL III (aka Ricin D ) 
and RCL IV are the toxins. Merck also reports the following LD50 per kg 
of bodyweight:-

Toxin                         Dose                 Test Animal
palytoxin                 60 nanograms               dog  (iv)
 ( from coral )          450     "                  mouse (iv)
 ( C129H223N3054 )    50-100     "                    "   (ip)
saxitoxin                3-5 micrograms             mouse (iv)
 ( from shellfish )       10     "                    "   (ip)   
 ( [C10H17N7O4]2+ )      263     "                    "   (oral). 
tetrodotoxin              10     "                  mouse (ip)
 ( from globefish )
aflatoxin M1             332 micrograms            duckling (oral)
aflatoxin M2             1.2 milligrams               "       "
aflatoxin B1             364 micrograms            duckling (oral)
aflatoxin B2             1.6 milligrams               "       "
aflatoxin G1             784 micrograms               "       "
aflatoxin G2             3.4 milligrams               "       "

The complex structure of palytoxin is shown in Merck, and it is listed as 
the most toxic non-proteinaceous substance known.

10.6  Where can I find laboratory safety guides?

The journals "Chemical Health and Safety", and "Journal of Chemical 
Education" have articles on many aspects of laboratory safety. Safety 
Officers and Laboratory Managers at educational institutions and companies 
are likely to have several guides, and a polite request should obtain a loan 
or copy of one, even if you aren't at that institution.  

There are several useful books. The most popular are:-
CRC Handbook of Laboratory Safety [4]
  - good general discussion of laboratory safety issues.
Hazards in the Chemical Laboratory [5]
  - good general discussion of laboratory safety concepts with data.
Guidelines for Laboratory Design: Health and Safety Considerations [12].
  - modern design concepts for new and refurbished laboratories.   
Laboratory Health and Safety Handbook: A Guide for the Preparation of a
Chemical Hygiene Plan [13]
  - such a plan is required by OSHA, and additional examples may also be 
    available from chemistry departments of local educational institutes.

10.7  Are contact lenses a hazard in laboratories?
 
There are a lot of myths about the occupational use of contact lenses, many
of which relate back to a Bethlehem Steel welder in Baltimore who, on the 
26 July 1967, accidentally caused an arc flash that hit his hard contact 
lens. He waited until the next day to report eyesight problems, and an 
ophthalmologist found severe ulcerations on his cornea, but attributed  
the damage to the wearing of the hard lenses for 17-18 hours after the
incident. The cornea healed completely in a few days, with no permanent
vision loss, and investigators found no link between the damage and the
arc flash, but the myth of the welder removing parts of the cornea with 
the lens, and consequently being permanently blinded, continues [14].

The banning of contact lenses from modern chemical laboratories is being
reconsidered in the light of increasing evidence that case-by-case
evaluations are more appropriate. Routine wearers of contact lenses may 
suffer " spectacle blur " when they switch to spectacles, and this temporary
reduction in visual efficiency could result in the misreading of labels.
Contact lenses are not eye protection devices, and OSHA believes that
if eye hazards are present, appropriate eye protection must be worn
instead of, or in conjunction with, contact lenses. There may still be some
laboratory environments where the provided personal protection equipment 
does not protect wearers of contact lenses, and they will remain banned.

There are three major areas of concern about the hazards of wearing
contact lenses in chemical laboratories. 

1. They can hold particulate or liquid material against the cornea.
   The modern soft contact lenses are considered suitable for most 
   environments, except where heavily contaminated with metal particles.
   Hard contact lenses are not considered suitable for use in 
   particle-contaminated areas.  

2. Contact lenses can be difficult to remove after a chemical splash.
   This is a concern, and is one reason why wearers of contact lenses in
   laboratories should be obviously identifiable to first-aid and 
   professional secondary care providers. The copious irrigation procedures 
   with water ( whilst holding the eye open ) that should immediately follow 
   chemical splashes may wash the lenses out, and trained staff can remove 
   any remaining lenses later. Experiments with concentrated sodium 
   hydroxide solution, sulfuric acid, acetic acid, acetone and n-butylamine 
   have shown that contact lenses may actually provide some protection [14].

3. Contact lenses may absorb and retain chemical vapours.
   This effect was not observed in the splash experiments above, and soft
   lenses have been shown to reduce the effect of acids, perhaps because 
   tears can dilute the acid by the time it passes through the lens.
   Some chemical vapours may be absorbed and retained, but often exposure
   should be eliminated by personal protection equipment anyway.

The January/February 1995 issue of Chemical Health and Safety had three
articles on contact lenses, including an excellent article on how to prepare 
for, and act during, contact lenses emergencies [15]. All three articles 
note that changing technologies have resulted in improved lenses that may 
now be acceptable in many modern laboratories, however the merits of each 
case should be carefully examined before approval. The issue of contact 
lenses in laboratories is still being carefully reviewed, as there are also
legal implications for both employers and employees, and laboratory safety 
literature should be monitored to obtain the latest perceptions [16,17].
   
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