Human: Any population and lifestage (occupational or general population, including children and other sensitive populations).

Animal: Non-human mammalian animal species (whole organism) of any lifestage (including fetal, early postnatal, adolescents and adults).

Relevant forms:

[substance X] (CAS number)

Other forms of [chemical X] that readily dissociate (e.g., list any salts, etc.).

Known metabolites of interest, including metabolites used to estimate exposures to [chemical X].

Human: Any exposure to [chemical X] via [oral or inhalation] route[s]. Studies will also be included if biomarkers of exposure are evaluated (e.g., measured chemical or metabolite levels in tissues or bodily fluids), but the exposure route is unclear or likely from multiple routes. Other exposure routes, such as those that are clearly dermal, are tracked during title and abstract screening and tagged as “potentially relevant supplemental material.”

Animal: Any exposure to [chemical X] via [oral or inhalation] route[s] of >1 day duration, or any duration assessing exposure during reproduction or development. Studies involving exposures to mixtures will be included only if they include an experimental arm with exposure to [chemical X] alone. Other exposure routes, including [dermal or injection], are tracked during title and abstract as “potentially relevant supplemental material.”

Human: A comparison or referent population exposed to lower levels (or no exposure/exposure below detection limits), or exposure for shorter periods of time, or cases versus controls, or a repeated measures design. However, worker surveillance studies are considered to meet PECO criteria even if no statistical analyses using a referent group is presented. Case reports or case series of > 3 people will be considered to meet PECO criteria, while case reports describing findings in 1–3 people will be tracked as “potentially relevant supplemental material.”

Animal: A concurrent control group exposed to vehicle-only and/or untreated control (control could be a baseline measurement, e.g., acute toxicity studies of mortality, or a repeated measure design).