Editing Toxicity (section)

===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.