All too often we see news stories of chemical industry practices that have had negative effects on health or the environment or hear reports of serious accidents or spills involving chemicals. An item in Chemical & Engineering News (December 8, 1997, p. 17) reported on "Hanford tanks leaking to groundwater." Groundwater was being contaminated with liquid wastes that had leaked from the tanks at the former nuclear weapons plant in Richland, Washington. The public perception of chemistry is tarnished by such stories, so chemists have a responsibility to use the safest possible practices in handling chemical substances and disposing of them. The American Chemical Society's 2007 document revised in 2012 "The Chemical Professional's Code of Conduct" contains these statements:
- Chemical professionals have a responsibility to serve the public interest and safety and to further advance the knowledge of science. They should actively be concerned with the health and safety of co-workers, consumers and the community.
- Chemical professionals should strive to do their work in ways that are safe for both the environment and for the health of all who may be affected. They have a responsibility to understand the health, safety and environmental impacts of their work, to recognize the constraints of limited resources, and to develop sustainable products and processes that protect the health, safety, and prosperity of future generations.
In this section, we will encounter printed and online sources to help keep abreast of the hazards associated with chemical substances and to become aware of the rules and regulations that govern the use of chemicals.
A large number of acronyms are found in the health and safety area, for example, TLV (Threshold Limit Value) or LD50 (lethal dose, 50%). There are also quite a few numerical identifiers, in addition to Chemical Abstracts Service Registry Numbers, that are used to identify chemical substances that have been studied for their environmental or health and safety impact. A single chemical substance may have a DOT (Department of Transportation) number, an RTECS number (from the Registry of Toxic Effects of Chemical Substances), and several others assigned by various US, European, International, or other agencies.
Furthermore, new types of chemical data, not likely to have been seen before, will be encountered for chemical substances in the reference tools or databases discussed in this section. These include things such as the octanol/water partition coefficient (Kow), soil organic carbon partition coefficient (Koc), measures of nitrification inhibition, acute toxicity data (two examples are short-term exposure limit (STEL) and threshold limit value-ceiling (TLV-C)), and others.
General Safety or Toxicology Information SourcesEdit
A good printed subject guide to environmentally-related topics is the Encyclopedia of Environmental Information Sources (1993). For over 800 subject areas, ranging from hazardous materials to alternative energy, the encyclopedia lists the major sources of information. Identified are specialized abstracting and indexing services, bibliographies, directories, encyclopedias and dictionaries, handbooks and manuals, online databases, and relevant organizations. Another guide specific to toxicology is Information Resources in Toxicology (4th ed., 2009). A general introduction to the discipline of toxicology and its history is provided, as well as individual chapters on resources for learning more about toxicology of various chemical classes and types of substances (e.g., metals, pesticides, dusts and fibers, etc.) and chapters on various aspects of topics like environmental, forensic, and genetic toxicology. Each chapter generally provides lists of books, journals, articles, websites, and/or organizations related to the specific subject
Mirroring the scope and depth of coverage found in the comprehensive treatises published by Elsevier in inorganic, organic, organometallic and other areas of chemistry is the 14-volume Comprehensive Toxicology (2nd edition, 2010), available electronically in the Knovel database. The work covers toxicology from the molecular to the organismal level, including a review of the general principles of toxicology, test procedures and data evaluation, and biotransformation of chemicals. The bulk of the volumes, however, are devoted to the specific organ systems of toxicology. Volume 14 treats current concepts of carcinogenesis.
Works encountered in other contexts, such as the Merck Index or the Kirk-Othmer Encyclopedia of Chemical Technology include quite a bit of information on the hazardous or safety aspects of the chemicals discussed. However, there are a large number of specialized reference tools whose primary aim is to make the retrieval of such information very easy. Some of those are introduced below.
Hazardous Aspects or Toxicology of ChemicalsEdit
Sax's Dangerous Properties of Industrial Materials, now in its 12th edition (2012), covers over 28,000 toxic, carcinogenic, mutagenic, highly flammable, or potentially explosive substances. Included are health and safety data, regulatory standards, toxicity and carcinogenicity information, and physical property profiles. There are many pages of synonyms in several languages to assist in using the work. It includes a CAS Registry Number index. An online version is also available.
Bretherick's Handbook of Reactive Chemical Hazards (7th ed., 2006) covers some 5,000 elements and compounds. Published in two volumes, Bretherick's first volume is devoted to specific information on the stability of the compounds or the reactivity of mixtures of two or more of them under various conditions. In volume 2 are found groups of chemical substances arranged on the basis of similarities in structure or reactivity. Stability data on single specific compounds, data on possible violent interaction between two or more compounds, general data on a class or group of compounds (or information on the identity of individual compounds in a known hazardous group), structures associated with explosive instability, and fire-related data are all included in the work. Information on how to use the handbook includes the important caveat "Do not assume that lack of information means that no hazard exists." Over 2,000 pages of information make this the work to consult first for hazardous reaction information.
Patty's Industrial Hygiene (6th ed. in 4 volumes, 2010) and Patty's Toxicology, (6th ed. in 6 volumes,2012) collectively cover General Principles, Toxicology, and Theory and Rationale. Patty's Industrial Hygiene supports the recognition and evaluation of chemical agents, physical agents, and biohazards in the workplace, as well as engineering control of exposure and personal protection. Patty's Toxicology provides an introduction to the field of toxicology and comprehensive toxicological data for industrial compounds. The focus of the work in recent editions has been extended beyond the industrial workplace to environmental safety and hazard control. It is now also available online.
The Dictionary of Substances and their Effects (DOSE) covers over 4,100 chemicals that have been studied for environmental impact or toxicity. The second edition of the print product appeared in 7 volumes in 1999. All purchasers of the print edition of DOSE receive free site-wide access to a fully searchable Web database. DOSE includes results of recent carcinogenicity, mutagenicity, and environmental fate studies, as well as the latest regulatory requirements.
Material Safety Data Sheets and Other Factual SourcesEdit
MSDSs or Material Safety Data Sheets are available from the manufacturer of chemical substances. It is to the manufacturer's advantage to insure that all known hazardous aspects and recommended precautions are clearly laid out to the user of their products, and that is the primary purpose of the MSDS. A very useful guide to MSDSs on the Internet includes sample MSDSs and sources of MSDSs, both on the Internet and elsewhere.
In 1983, the US Occupational Safety and Health Administration (OSHA) published the Hazard Communication Standard, requiring chemical manufacturers and distributors to provide MSDSs to their customers beginning in late 1985. Since 1993, chemical manufacturers in the US have followed a voluntary MSDS format that is endorsed by the American National Standards Institute (ANSI). The most important information appears at the top, followed by the chemical name, manufacturer, and composition. The third section identifies known hazards associated with the substance. First-aid measures are next, followed by fire-fighting measures.
The most critical parts of an MSDS are the human health hazards and acceptable exposure limits. However, data on human testing is rare, so MSDSs generally rely on animal test data. The international equivalents of the U.S. MSDSs are much shorter. Those are called "International Chemical Safety Cards (ICSCs) and are published by the World Health Organization and the European Union. Such documents as MSDSs and ICSCs are really geared toward the larger quantities of chemicals used in industry. For academic institutions, although MSDSs are still required on site, a book such as the US National Research Council's Prudent Practices in the Laboratory: Handling and Disposal of Chemicals contains much practical information. The book includes Laboratory Chemical Safety Summaries (LCSSs) that provide the same type of information as do MSDSs, but are geared for the laboratory user. Also found in the work are guidance on risk assessment and tips on how to work with laboratory equipment. The Syracuse Research Corporation (SRC) maintains a useful metasearch site, FatePointers, that searches a number of toxicological data sources including the National Library of Medicine, the USEPA, and a demo version of SRC's PHYSPROP database]covering key property information on over 25,000 substances.
The National Library of Medicine's SystemEdit
NLM's TOXNET (Toxicology Data Network) is a metasearch engine accessing from a single search screen many free toxicology databases including some that formerly cost money to search. Included are:
- Toxicology Data Search for factual information in the databases HSDB (see below), Gene-Tox, CCRIS (carcinogenesis), and IRIS (EPA's risk assessment database)
- Toxicology Literature Search for thousands of bibliographic records from TOXLINE and the genotoxic/reproductive database DART
- TRI (Toxic Release Inventory) Search, reporting EPA's annual estimate of releases of toxic substances into the environment
- ChemIDplus is a chemical substance database searchable by chemical name, CAS Registry Number, structure, physical property ranges, toxicity value ranges, molecular weight, etc. It searches
ChemIDplus contains >400,700 records and >308,000 structures;, HSDB: >5,000 records; and NCI-3D: >400,000 pharmaceutical substances). Links are provided to information for each substance for nearly all the TOXNET databases, other important U.S. government databases, and federal/state regulatory lists.
The Hazardous Substances Data Bank or(HSDB) contains over 5,000 chemical records, each of which can have as many as 150 or so fields of data, covering human health effects, emergency medical treatment, animal toxicity studies, metabolism/pharmacokinetics, pharmacology, environmental fate and exposure, environmental standards and regulations, chemical/physical properties, chemical safety and handling, occupational exposure standards and more. HSDB is peer-reviewed by a committee of experts, the Scientific Review Panel (SRP).
The Canadian Centre for Occupational Health and Safety (CCOHS's Databases)Edit
Among the numerous reasonably priced databases offered by CCOHS is RTECS, the Registry of Toxic Effects of Chemical Substances. RTECS was originally produced by the US National Institute for Occupational Safety and Health (NIOSH), but has now been outsourced to Elsevier. RTECS provides toxicological information with citations on over 140,000 chemical substances. Included are toxicological data and reviews, international workplace exposure limits, references to US standards and regulations, analytical methods, and exposure and hazard survey data. RTECS contains:
- > 400,000 chemical names and synonyms
- > 130,000 unique CAS numbers
- toxicity data such as LD50 or LC50 (lethal dosages/concentrations) values
- tumorigenic and reproductive effects
- carcinogenicity status.
CCOHS also maintains an extensive Material Safety Data Sheet collection and other databases covering aspects of occupational safety and health that range to ergonomics/workplace design and psychological aspects of a safe workplace environment. CCOHS offers a free web search across all of their databases through the Web Information Service, but only subscribers can see some of the records.
Chemical Abstracts Service (CAS) DatabasesEdit
Incorporated into the results of substance searches on SciFinder is a link to Chemical Abstracts Service's CHEMLIST database, a source of regulatory information for over 309,000 chemical substances covering 1979 to the present. CHEMLIST was originally built from data in the 1985 US Toxic Substances Control Act (TSCA) Inventory and supplements, and updates from the U.S. Government's Federal Register. Now more than 100 additional collections of data are included, such as web sites, official government lists, gazettes, newsletters, bulletins, and electronic data feeds. The records contain substance identity information, inventory status, source of information, and summaries of regulatory activity, reports, and other compliance information.
SciFinder also pulls out key toxicity data from their literature file (CAPlus) and includes this information in the extensive experimental properties list attached to the substance records. SciFinder has a massive literature database that combines CAPlus (1907+) and MEDLINE (1946+), the premier National Library of Medicine health sciences database. Over 62 million journal article, report, patent, conference papers, and other documents can be searched by substance or keywords and the results limited to toxicology and related areas. CAPlus and MEDLINE can be searched on STN International interfaces while MEDLINE can be searched on numerous subscription search systems as well as the free PUBMED database.
CAS has also created a multidatabase product called TOXCENTER(Toxicology Center) which is accessed their STN International interface. It is a bibliographic database that covers the pharmacological, biochemical, physiological, and toxicological effects of drugs and other chemicals. TOXCENTER is composed of the data from 20 sources, including:
- BIOSIS (Biological Abstracts): 1926 to the present
- CAplus (Chemical Abstracts): 1907 to the present
- IPA (International Pharmaceutical Abstracts): 1970 to the present
- MEDLINE: 1946 to the present.
The records in the file contain bibliographic data, abstracts, indexing terms, chemical names, and CAS Registry Numbers.
Elsevier incorporates in its subscription REAXYS database system content from the original Beilstein/EcoPharm organic chemistry database that started indexing pharmacological/toxicological data in 1980. For "Isatin" (BRN 383659) there are 47 entries (October 2006) for its bioactivity, among which are information on MAO-inhibiting activity, acute toxicity, and other biological activity of the substance. Bear in mind that REAXYS should not be considered a comprehensive source of such data given its recent starting date. For the time from 1980 - 1990 the information is unstructured, and only a note field and a reference are given. From 1990 onwards the information is organized into the hierarchical system, making it possible to search for specific effects, data etc. Note that although REAXYS contains nearly all of the electronic Beilstein content, the Beilstein brand name has been completely disassociated from REAYS.
The EcoPharm module (originally an add-on to Beilstein) was integrated into Beilstein which was integrated into REAXYS. EcoPharm's pharmacological and toxicological data focus on:
- human and mammalian toxicology, drug treatment, pharmaceutical and biological chemistry
- ecological data concerned with effects of chemicals on various ecosystems, their environmental fate and potential for accumulation as well as health threat in the environment.
See REAXYS help documentation for details in searching this information. REAXYS includes a patent chemistry database; Gmelin content, both from the original print version and updated information on inorganics and organometallics); and the previously mentioned Beilstein content and continuing updates.
Elsevier also produces EMBASE, a major international biomedical literature database available by subscription on a number of search platforms. Coverage of pharmacetical and toxicological information is very strong.
Elsevier also offers additional subscription databases/electronic reference works including:
US Government SourcesEdit
The U.S. Environmental Protection Agency (EPA) maintains a Substance Registry System to assist in locating chemical and biological substances whose properties make them of concern to the EPA. Chemicals are identified by a Chemical Abstracts Service Registry Number (CASRN) or if not available, an EPA Chemical Identifier (EPA ID), a systematic name (generally the CAS 9th Collective Index Name), a molecular formula, a molecular weight, former CASRN references, synonyms, and information about regulations, EPA data systems, and other sources that list the chemical. Other resources at EPA include:
- Aggregated Computational Toxicology Resource (ACToR) - EPA's online warehouse of all publicly available chemical toxicity data which can be used to find all publicly available data about potential chemical risks to human health and the environment.
- Envirofacts - A national information system that provides a single point of access to data extracted from seven major EPA databases.
- Health and Environmental Research Online (HERO) - Indexes more than 600,000 scientific references and data from the peer-reviewed literature used by EPA to develop its regulations regarding toxic substances and risk assessment.
- Terminology Services - This contains collections of environmental terms and definitions from a variety of sources, and can be searched by keyword, information resource, and organization.
- Ecotox database - searches single chemical toxicity data from three U.S. Environmental Protection Agency (U.S. EPA) ecological effects databases; AQUIRE, TERRETOX, and PHYTOTOX. The AQUIRE and TERRETOX databases contain information on lethal, sublethal and residue effects. The AQUIRE database includes toxic effects data on all aquatic species including plants and animals and freshwater and saltwater species. TERRETOX is the terrestrial animal database. It's primary focus is wildlife species but the database does include information on domestic species. PHYTOTOX is a terrestrial plant database that includes lethal and sublethal toxic effects data.
The main U.S. Department of Agriculture resource is AGRICOLA (Agricultural Online Access) that searches both the National Agricultural library catalog and a database of journal articles, reports, patents and other document back to 1970. Significant information on the toxicological and environmental aspects of pesticides and other agricultural chemicals, food, animal feed products, and veterinary medicines. Strong coverage of the impact and fate of toxic chemicals in ecological systems and on individual plant and animal species is provided.
Much information is available from other governmental agencies such as the:
- Agency for Toxic Substances and Disease Registry (ATSDR)- the lead CDC public health agency for response to releases of hazardous substances into the environment and also participates in policy development for environmental health-related issues. Among the resources they maintain on their web site are Toxicological Profiles for over 285 chemicals, ToxFAQs summaries, and the CERCLA Priority List of Hazardous Substances.
- National Institute of Environmental Health Sciences (NIEHS) - whose mission is to reduce human illness and dysfunction from environmental causes. The NIEHS home page provides links to Environmental Health Topics (A-Z), the peer-reviewed journal Environmental Health Perspectives, and the National Toxicology Program.
- National Center for Toxicological Research - this Food and Drug Administration center web site provides a wealth of information of toxicology issues related to food supply and pharmaceuticals.
- National Institute for Occupational Safety and Health (NIOSH)- Also part of the CDC, NIOSH covers all possible workplace hazards including radiation, toxic substances, noise, and indoor air pollution. Links are provided to an impressive array of databases, publications, criteria documents, software, multimedia, and manuals.
The gateway to most US federal government sources now is USA.Gov. "Environment, Energy, and Agriculture" is one of the main categories that citizens can choose at this site.
The Royal Society of Chemistry has produced since 1981 a bibliographic database called the Chemical Safety NewsBase (CSNB). It covers health and safety hazards of chemicals in relevant industries.
BIOSIS Previews, a subscription database now produced and owned by Thomson Reuters, is an enhanced version of Biological Abstracts. BIOSIS is a comprehensive life sciences database covering journal literature, conference papers, U.S. patents, and books. It covers the fields of agriculture, biochemistry, bioinformatics, biomedicine, biotechnology, botany, genetics, and much more. Although it is available electronically from 1926 to present, back files must be purchased so searchers at subscribing institutions need to check how far back in time their subscription goes. It is available on multiple search platforms including Thomson's own Web of Science. Many institutions will have older years in print. Check your library's catalog for Biological Abstracts.
With BIOSIS, often simple keyword searching can retrieve many useful toxicological references. However, because of the database size and wide range of topics, searching specific fields for controlled index terms and classification codes is frequently required to create a more complete and, at the same time, focused set of results. One should review the search tips and help on the specific search platform being used.
There are many other sources in which to find chemical safety, toxicological, or environmental information. Examples are specialized abstracting services such as Water Resources Abstracts, publications from organizations such as the National Fire Protection Association or the American Chemical Society. In addition, there is a wealth of publications in these areas by commercial publishers, such as Handbook of Toxicology, 3rd edition (CRC Press, 2014).
The safe manufacture and use of chemical substances (including drugs) is of paramount importance. Much of the relevant information in the area of chemical health and safety and environmental impact of chemicals is found in mission-oriented abstracting and indexing services. There are specialized databases that deal with physical properties of environmental interest, such as PHYSPROP or health impacts of chemicals, including carcinogenicity, mutagenicity, etc. Material Safety Data Sheets (MSDSs) are another important source of relevant data. Both government agencies and commercial publishers produce many good reference sources in this area.
- Encyclopedia of environmental information sources / edited by Sarojini Balachandran. Detroit : Gale Research, 1993. ISBN:0810385686
- Information Resources in Toxicology / edited by Philip Wexler. 4th ed. Amsterdam, Boston: Elsevier/AP, 2009. ISBN: 9780123735935.