Wikipedia:Manual of Style/Chemistry/Safety

Source: Wikipedia, the free encyclopedia.

The majority of compounds could be described by a long list of potential hazards as well as H&P phrases. Wikipedia does not aspire to be a surrogate for MSDS and does not provide advice as a matter of policy. The hazards associated with most chemical compounds are adequately described in the Chembox via GHSPictograms, GHSSignalWord, NFPA, or MainHazard parameters; further elaborated in H and P phrases.

When the safety section is warranted beyond the information in the Chembox, information should be succinctly presented. Pertinent information could be

LD50 and TLV. Editors recognize that all chemical compounds could be abused and can be dangerous under diverse circumstances. In cases where the mechanism of toxicity is noteworthy in a chemical context, e.g., the inhibition of myoglobin by carbon monoxide, a separate section within the article is often desirable because it illuminates the chemical subject. In a few cases where the literature and lore on toxicity is extensive, such as cyanide, an entire separate article can be warranted, e.g. cyanide poisoning. Obvious hazards that depend on knowledge of basic chemistry do not warrant inclusion. For example, since hexafluorophosphoric acid
is a strong acid, it is not necessary to state that it should be stored away from bases and reactive metals.


News reports of spills or accidents associated with a chemical compound, even though they may be tragic, are usually not notable. The description of hazards should avoid anecdotes. The role of Wikipedia is to give balanced and accurate information, allowing readers to reach their own conclusions. Hazards should be peer reviewed, and not taken from newspaper accounts. If an event is potentially significant enough to warrant inclusion as a safety hazard, first post it to the discussion page and discuss it with the Wikipedia community.

Descriptions of hazards should, as far as possible, be based on published, peer-reviewed sources, which should be cited at the appropriate point in the article. A list of resources for chemical safety information is given in the external links section of these guidelines.

Coverage of regulations

In the usual encyclopedic way, the Project avoids serving either as a safety manual or a guide to regulation.


If a chemical is used as a pesticide, most likely its use is subject to extensive regulation, which will vary from country to country, and even depend on the province or state within many countries. Furthermore, most regulations change with time. Prudence must be exercised in covering such regulatory topics.


Depending on the extent of the information, this content may be incorporated into the Safety section or it may be a separate section on its own. If the compound is a drug, follow WikiProject Pharmacology's recommendations.

As indicated by

What Wikipedia is not
, editors are discouraged from providing advice about poisons or emergencies associated with chemical compounds: "a Wikipedia article should not read like a how-to style manual of instructions, advice (legal, medical, or otherwise) or suggestions."


If a chemical is used as a pesticide, most likely its use is subject to extensive regulation, which will vary from country to country, and even depend on the province or state within many countries. Furthermore, most regulations change with time. Prudence must be exercised in covering such regulatory topics.

Sources of safety information

Secondary sources (UN agencies)

International Programme on Chemical Safety (IPCS)

The IPCS is a joint programme of three United Nations specialized agencies (WHO, ILO, UNEP) with the collaboration of many other national and international bodies. It publishes several series of documents which may be of use here: these are peer-reviewed reviews, but are often long and technical. The three main ones are

Other IPCS publications which might be of use in specific circumstances include:

International Agency for Research on Cancer (IARC/CIRC)

The IARC (CIRC in its French acronym) is an agency of the World Health Organization based in Lyon, France. It publishes a series of Monographs on carcinogenic risks to humans which are very widely used around the world. Summary evaluations are available for all chemicals which have been classified as carcinogens by the IARC, and in some cases the full text of the monograph is available free of charge. These are a preferred source when discussing human carcinogenicity.

International Chemical Safety Cards

These are also published by the IPCS, but are much shorter than other IPCS publications (two pages!) and intended for a non-technical audience. They do not include citations to the original literature, but are peer-reviewed. They are particularly useful for providing basic chemical information (in the absence of a more specific source), and in providing NFPA-ratings which have been peer-reviewed (otherwise difficult to find).

Secondary sources (EU and national)

European Union

European Chemicals Agency (ECHA)

The ECHA is the main site for EU-related chemical safety concerning e.g. REACH and CLP Regulation. Full GHS assessments of more than 100,000 chemicals with a European Community number, i.e. in the European market are available.

European Agency for Safety and Health at Work (EU-OSHA)

The EU-OSHA site contains information of a more general nature about the use of chemicals in the workplace.

United States

Occupational Safety and Health Administration (OSHA)

The OSHA is the federal agency charged with

Permissible Exposure Limits (PELs) [4]
are the legally enforceable standards for workplace contamination in the U.S.

National Institute for Occupational Safety and Health (NIOSH)

NIOSH is a federal agency concerned more with research and training rather than with regulation. Its Pocket Guide to Chemical Hazards is a widely used summary of basic safety information, but mostly redundant to

IDLH values (for "Immediately Dangerous to Life and Health", available here
) are a useful response to the common question "how much of this chemical will kill me?"

Environmental Protection Agency (EPA)

The EPA is mostly concerned with pesticides and environmental polluants, information on which can be found through the Prevention, Pesticides and Toxic Substances site. Its Acute Exposure Guidance Levels (AEGLs) give one response to questions about "safe" levels of chemicals for the general population (rather than in workplace situations).

Food and Drug Administration

The FDA is the source for U.S.-related information about food and cosmetics questions. Its EAFUS database ("Everything Added to Food in the United States") is a particularly useful starting point to find information.

Centers for Disease Control and Prevention (CDC)

The CDC promote public health in general, and most of their work on occupational health is conducted through NIOSH. However, their Emergency Preparedness & Response site is a useful secondary source of information on some more exotic compounds, such as chemical weapons, for which little reliable information is available elsewhere.

Agency for Toxic Substances and Disease Registry (ATSDR)

The ATSDR is a federal agency which publishes Toxicological Profiles on just over 300 substances. These are fairly long and technical, and often redundant to CICADs or similar documents.

National Toxicology Program

The National Toxicology Program of the Department of Health and Human Services publishes a regular Report on Carcinogens: the most recent available version is the 11th ed. The IARC Monographs (see above) are preferred as a source for carcinogenicity information, as they cover more substances in greater depth, but the NTP report is also reliable. The report also links to many other federal regulations concerning the substances listed.

Hazardous Substances Data Bank (HSDB)

From the

National Library of Medicine, available via TOXNET

United Kingdom

Health and Safety Executive (HSE)

The HSE is responsible for promotion and enforcement of health and safety regulations in the UK. This page provides a variety of general publications about various chemical hazards.


Much of the regulation of occupation exposure to chemical substances in Canada is of provincial competence. There is a federal classification system, the

Canadian Environmental Protection Act of 1999
(CEPA 1999).


New Zealand

Environmental Risk Management Authority (ERMA)



National Institute of Technology and Evaluation (NITE)

Secondary sources (encyclopedias)

The standard reference work for chemical safety, other than the sites and monographs given above, is Sax's Dangerous Properties of Industrial Materials, currently on its 11th edition (2004, 4860 pages). It is available in most university libraries and in many large public libraries, and some universities have local access to a CD-ROM version. In citing Sax's, it is not necessary that the most up-to-date edition is used, although that is obviously preferable if you have access to it.

  • Lewis, Richard J., ed. (2004), Sax's Dangerous Properties of Industrial Materials (11th ed.), London: Wiley,

The monographs of the

Threshold Limit Values
(TLVs) have not been widely used as a source on Wikipedia, as they are not accessible to most editors: however, they are widely cited by other secondary sources in the field and so would constitute a reliable secondary source if need be. Note that TLVs are not legally enforceable in the United States, although they have been cited in civil lawsuits as an example of industry best practice.

Primary sources

Editors are strongly discouraged from using the primary literature (e.g. journal articles) as sources for chemical safety information.

Material Safety Data Sheets (MSDSs)


Material Safety Data Sheets present several problems as sources: these problems are shared by the various collections of MSDSs kept and compiled by university chemistry departments and by data retrieved from IUCLID

  • They are not peer-reviewed. Although they are usually competently complied, peer-reviewed sources are always better.
  • There are noticeable differences between the MSDSs of different companies. In particular, MSDSs written for distribution in the United States are noticeably harsher on the perceived hazards of a given chemical than those written from distribution in Europe (this almost certainly stems from the different legal frameworks for these documents). Which version should we choose as our source?
  • They are commercial documents, usually held on the supplier's website: why should we favour one supplier over another in linking to their sites?

As a counterbalance to these problems, MSDSs or IUCLID are often the only available source of safety information for a particular chemical: indeed, they may be the only available source of basic chemical data such as melting points. If that is the case, a separate safety section is inappropriate. However the relevant summary data may be included in the chembox, with the MSDS as a reference or included in the ExternalMSDS field (label the link as "External MSDS", not with the company name).