Editing Toxicity (section)

==Classification==
[[File:GHS-pictogram-skull.svg|thumb|The [[Globally Harmonized System of Classification and Labeling of Chemicals|international]] [[GHS hazard pictograms|pictogram]] for toxic chemicals.]]

For substances to be regulated and handled appropriately they must be properly classified and labelled. Classification is determined by approved testing measures or calculations and has determined cut-off levels set by governments and scientists (for example, [[no-observed-adverse-effect level]]s, [[threshold limit value]]s, and [[tolerable daily intake]] levels). [[Pesticide]]s provide the example of well-established [[toxicity class]] systems and [[toxicity label]]s. While currently many countries have different regulations regarding the types of tests, numbers of tests and cut-off levels, the implementation of the [[Globally Harmonized System of Classification and Labelling of Chemicals|Globally Harmonized System]]<ref>{{cite web|url=http://www.unece.org/trans/danger/publi/ghs/ghs_welcome_e.html|title=About the GHS - Transport - UNECE|access-date=2008-11-04|archive-date=2020-11-14|archive-url=https://web.archive.org/web/20201114001856/http://www.unece.org/trans/danger/publi/ghs/ghs_welcome_e.html|url-status=live}}</ref><ref>{{cite web|url=http://www.epa.gov/oppfead1/international/globalharmon.htm|title=Pesticide Labels and GHS: Comparison and Samples|first=US|last=EPA, OCSPP, OPP|date=2015-08-25|access-date=2008-11-04|archive-date=2015-09-24|archive-url=https://web.archive.org/web/20150924121837/http://www.epa.gov/oppfead1/international/globalharmon.htm|url-status=live}}</ref> has begun unifying these countries.

Global classification looks at three areas: Physical Hazards (explosions and pyrotechnics),{{fact|date=January 2025}} Health Hazards{{fact|date=January 2025}} and [[environmental hazard]]s.{{fact|date=January 2025}}

===Health hazards===
The types of toxicities where substances may cause lethality to the entire body, lethality to specific organs, major/minor damage, or cause cancer. These are globally accepted definitions of what toxicity is.{{fact|date=January 2025}} Anything falling outside of the definition cannot be classified as that type of toxicant.{{fact|date=January 2025}}

====Acute toxicity====
{{Main|Acute toxicity}}
{{See also|Lethal dose}}
{{More citations needed section|date=August 2009}}
Acute toxicity looks at lethal effects following oral, dermal or inhalation exposure. It is split into five categories of severity where Category 1 requires the least amount of exposure to be lethal and Category 5 requires the most exposure to be lethal. The table below shows the upper limits for each category.

{| class="wikitable"
|-
! Method of administration
! Category 1
! Category 2
! Category 3
! Category 4
! Category 5
|-
| Oral: {{LD50}} measured in mg/kg of bodyweight
| 7
| 50
| 300
| 2 000
| 5 000
|-
| Dermal: LD<sub>50</sub> measured in mg/kg of bodyweight
| 50
| 200
| 1 000
| 2 000
| 5 000
|-
| Gas Inhalation: [[LC50|LC<sub>50</sub>]] measured in [[Ppmv|ppmV]]
| 100
| 500
| 2 500
| 20 000
| Undefined
|-
| Vapour Inhalation: LC<sub>50</sub> measured in mg/L
| 0.5
| 2.0
| 10
| 20
| Undefined
|-
| Dust and Mist Inhalation: LC<sub>50</sub> measured in mg/L
| 0.05
| 0.5
| 1.0
| 5.0
| Undefined
|}

Note: The undefined values are expected to be roughly equivalent to the category 5 values for oral and dermal administration.{{Citation needed|date=April 2010}}

====Other methods of exposure and severity====
Skin corrosion and irritation are determined through a skin patch test analysis, similar to an [[Patch test|allergic inflammation patch test]]. This examines the severity of the damage done; when it is incurred and how long it remains; whether it is reversible and how many test subjects were affected.

'''Skin corrosion''' from a substance must penetrate through the epidermis into the dermis within four hours of application and must not reverse the damage within 14 days. '''Skin irritation''' shows damage less severe than corrosion if: the damage occurs within 72 hours of application; or for three consecutive days after application within a 14-day period; or causes [[inflammation]] which lasts for 14 days in two test subjects. '''Mild skin irritation''' is minor damage (less severe than irritation) within 72 hours of application or for three consecutive days after application.

Serious '''[[Human eye|eye]] damage''' involves tissue damage or degradation of vision which does not fully reverse in 21 days. Eye irritation involves changes to the eye which do fully reverse within 21 days.

====Other categories====
* Respiratory sensitizers cause breathing hypersensitivity when the substance is inhaled.
* A substance which is a skin sensitizer causes an [[allergic response]] from a dermal application.
* [[Carcinogen]]s induce cancer, or increase the likelihood of cancer occurring.
*[[Neurotoxicity]] is a form of toxicity in which a biological, chemical, or physical agent produces an adverse effect on the structure or function of the [[Central nervous system|central]] or [[peripheral nervous system]]. It occurs when exposure to a substance – specifically, a [[neurotoxin]] or [[neurotoxicant]]– alters the normal activity of the nervous system in such a way as to cause permanent or reversible damage to [[nervous tissue]]. 
* Reproductively toxic substances cause adverse effects in either sexual function or [[fertility]] to either a parent or the offspring.
* Specific-target organ toxins damage only specific organs.
* Aspiration hazards are solids or liquids which can cause damage through inhalation.

===Environmental hazards===
An Environmental hazard can be defined as any condition, process, or state adversely affecting the environment. These hazards can be physical or chemical, and present in air, water, and/or soil. These conditions can cause extensive harm to humans and other organisms within an ecosystem.

====Common types of environmental hazards====
* [[water pollution|Water]]: detergents, fertilizer, raw sewage, prescription medication, pesticides, herbicides, heavy metals, PCBs
* [[soil contamination|Soil]]: heavy metals, herbicides, pesticides, PCBs
* [[air pollution|Air]]: particulate matter, carbon monoxide, sulfur dioxide, nitrogen dioxide, asbestos, ground-level ozone, lead (from aircraft fuel, mining, and industrial processes)<ref>"Basic Information about Lead Air Pollution." EPA. Environmental Protection Agency, 17 Mar. 2017. Web. Beaubier, Jeff, and Barry D. Nussbaum. "Encyclopedia of Quantitative Risk Analysis and Assessment." Wiley. N.p., 15 Sept. 2008. Web.
"Criteria Air Pollutants." EPA. Environmental Protection Agency, 2 Mar. 2017. Web. "USEPA List of Priority Pollutants." The Environmental Science of Drinking Water (2005): 243–45. EPA, 2014. Web
"What Are Some Types of Environmental Hazards?" Reference. IAC Publishing, n.d. Web.
</ref>
The EPA maintains a list of priority pollutants for testing and regulation.<ref>{{cite web |title=Priority Pollutant List |url=https://www.epa.gov/sites/default/files/2015-09/documents/priority-pollutant-list-epa.pdf |date=December 2014 |access-date=2024-07-14 |archive-date=2024-05-15 |archive-url=https://web.archive.org/web/20240515002925/https://www.epa.gov/sites/default/files/2015-09/documents/priority-pollutant-list-epa.pdf |url-status=live }}</ref>

====Occupational hazards====
Workers in various occupations may be at a greater level of risk for several types of toxicity, including neurotoxicity.<ref>{{Cite book|title=Environmental neurotoxicology|date=1992|publisher=National Academy Press|others=National Research Council (U.S.). Committee on Neurotoxicology and Models for Assessing Risk.|isbn=0-585-14379-X|location=Washington, D.C.|oclc=44957274}}</ref>  The expression "Mad as a hatter" and the "Mad Hatter" of the book [[Alice in Wonderland]] derive from the known occupational toxicity of [[hatters]] who used a toxic chemical for controlling the shape of hats. Exposure to chemicals in the workplace environment may be required for evaluation by industrial hygiene professionals.<ref>{{cite web|url=http://www.inchem.org/documents/ehc/ehc/ehc223.htm#_223410000|title=Environmental health criteria: Neurotoxicity risk assessment for human health: Principles and approaches|date=2001|publisher=United Nations Environment Programme, the International Labour Organization and the World Health Organization, Geneva|access-date=2019-12-18|archive-date=2021-02-27|archive-url=https://web.archive.org/web/20210227091328/http://www.inchem.org/documents/ehc/ehc/ehc223.htm#_223410000|url-status=live}}</ref>

=====Hazards for small businesses=====
=====Hazards from medical waste and prescription disposal=====
=====Hazards in the arts=====
Hazards in the arts have been an issue for artists for centuries, even though the toxicity of their tools, methods, and materials was not always adequately realized. Lead and cadmium, among other toxic elements, were often incorporated into the names of artist's oil paints and pigments, for example, "lead white" and "cadmium red".

20th-century printmakers and other artists began to be aware of the toxic substances, toxic techniques, and toxic fumes in glues, painting mediums, pigments, and solvents, many of which in their labelling gave no indication of their toxicity. An example was the use of [[xylol]] for cleaning [[silk screens]]. Painters began to notice the dangers of breathing painting mediums and thinners such as [[turpentine]]. Aware of toxicants in studios and workshops, in 1998 printmaker [[Keith Howard]] published ''Non-Toxic Intaglio Printmaking'' which detailed twelve innovative [[Intaglio (printmaking)|Intaglio]]-type printmaking techniques including [[photo etching]], [[digital imaging]], [[Acrylic paint|acrylic]]-resist hand-etching methods, and introducing a new method of [[non-toxic]] [[lithography]].<ref>{{cite book |last1=Howard |first1=Keith John |title=Non-toxic Intaglio Printmaking |date=1998 |publisher=Printmaking Resources |isbn=978-0-9683541-0-0 }}{{pn|date=January 2025}}</ref>

====Mapping environmental hazards====
There are many environmental health mapping tools. [[TOXMAP]] is a Geographic Information System (GIS) from the Division of Specialized Information Services<ref>{{cite web|url=http://sis.nlm.nih.gov/|title=Reliable information on K-12 science education, chemistry, toxicology, environmental health, HIV/AIDS, disaster/emergency preparedness and response, and outreach to minority and other specific populations.|access-date=2010-09-21|archive-date=2019-03-21|archive-url=https://web.archive.org/web/20190321193634/http://sis.nlm.nih.gov/|url-status=dead}}</ref> of the [[United States National Library of Medicine]] (NLM) that uses maps of the United States to help users visually explore data from the [[United States Environmental Protection Agency]]'s (EPA) [[Toxics Release Inventory]] and [[Superfund]] programs. TOXMAP is a resource funded by the US Federal Government. TOXMAP's chemical and environmental health information is taken from NLM's Toxicology Data Network 
(TOXNET)<ref>{{cite web|url=http://toxnet.nlm.nih.gov/|title=TOXNET|access-date=2010-09-21|archive-date=2019-06-11|archive-url=https://web.archive.org/web/20190611080606/https://toxnet.nlm.nih.gov/|url-status=live}}</ref> and [[PubMed]], and from other authoritative sources.

====Aquatic toxicity====
[[Aquatic toxicity]] testing subjects key indicator species of [[fish]] or [[crustacea]] to certain concentrations of a substance in their environment to determine the lethality level. Fish are exposed for 96 hours while crustacea are exposed for 48 hours. While GHS does not define toxicity past 100&nbsp;mg/L, the EPA currently lists aquatic toxicity as "practically non-toxic" in concentrations greater than 100 ppm.<ref>{{Cite web|url=http://www.epa.gov/oppefed1/ecorisk_ders/toera_analysis_eco.htm|title=EPA: Ecological risk assessment|access-date=2008-11-04|archive-date=2015-09-30|archive-url=https://web.archive.org/web/20150930060202/http://www.epa.gov/oppefed1/ecorisk_ders/toera_analysis_eco.htm|url-status=live}}</ref>

{| class="wikitable"
|-
! Exposure
! Category 1
! Category 2
! Category 3
|-
| Acute
| ≤ 1.0&nbsp;mg/L
| ≤ 10&nbsp;mg/L
| ≤ 100&nbsp;mg/L
|-
| Chronic
| ≤ 1.0&nbsp;mg/L
| ≤ 10&nbsp;mg/L
| ≤ 100&nbsp;mg/L
|}

Note: A category 4 is established for chronic exposure, but simply contains any toxic substance which is mostly insoluble, or has no data for acute toxicity.