The term '''human equivalent''' is used in a number of different contexts. This term can refer to human equivalents of various comparisons of animate and inanimate things.

==Animal models in chemistry and medicine{{anchor|Human equivalent dose}}==

Animal models are used to learn more about a disease, its diagnosis and its treatment, with animal models predicting human toxicity in up to 71% of cases.<ref>{{cite journal |vauthors=Olson H, Betton G, Robinson D, etal |title=Concordance of the toxicity of pharmaceuticals in humans and in animals |journal=Regul. Toxicol. Pharmacol. |volume=32 |issue=1 |pages=56–67 |year=2000 |pmid=11029269 |doi=10.1006/rtph.2000.1399 |s2cid=17158127 }}</ref> The '''human equivalent dose''' (HED) or '''human equivalent concentration''' (HEC) is the quantity of a chemical that, when administered to humans, produces an effect equal to that produced in test animals by a smaller dose.<ref>BusinessDictionary.com definition. [http://www.businessdictionary.com/definition/human-equivalent-dose.html] {{Webarchive|url=https://web.archive.org/web/20190606031029/http://www.businessdictionary.com/definition/human-equivalent-dose.html |date=2019-06-06 }}.</ref> Calculating the HED is a step in carrying out a clinical trial of a pharmaceutical drug.<ref>U.S. Food & Drug Administration. Estimating the Safe Starting Dose in Clinical Trials for Therapeutics in Adult Healthy Volunteers. [https://web.archive.org/web/20030210170632/http://www.fda.gov/cber/gdlns/dose.htm].</ref>

==Human energy usage and conversion== The concept of human-equivalent energy (H-e) assists in understanding of energy flows in physical and biological systems by expressing energy units in human terms: it provides a “feel” for the use of a given amount of energy by expressing it in terms of the relative quantity of energy needed for human metabolism,<ref>Bicycle calculator: speed, weight, wattage etc. [http://bikecalculator.com/].</ref> assuming an average human energy expenditure of 12,500 kJ per day and a basal metabolic rate of 80 watts.<ref>Cross, R. & Spencer, R. 2008. ''Sustainable gardens''. CSIRO Publishing, Collingwood, Melbourne. {{ISBN|978-0-643-09422-2}}.</ref> A light bulb running at 100 watts is running at 1.25 human equivalents (100/80), i.e. 1.25 H-e. On the other hand, a human may generate as much as 1,000 watts for a task lasting a few minutes, or even more for a task of a few seconds' duration, while climbing a flight of stairs may represent work at a rate of about 200&nbsp;watts.<ref>{{cite web |url=http://www.uic.edu/aa/college/gallery400/notions/human%20energy.htm |title=Home |website=www.uic.edu |access-date=2009-05-29}}</ref>

==Animal attributes expressed in terms of human equivalents==

===Cat and dog years=== The ages of domestic cats and dogs are often referred to in terms of "cat years" or "dog years", representing a conversion to human-equivalent years. One formula for cat years is based on a cat reaching maturity in approximately 1 year, which could be seen as 16 in human terms, then adding about 4 years for every year the cat ages. A 5-year-old cat would then be (5 − 1) × 4 + 16 = 32 "cat years" (i.e. human-equivalent years), and a 10-year-old cat (10 − 1) × 4 + 16 = 52 in human terms.<ref>{{cite web |url=https://www.metpet.com/Reference/Cats/Health/cat_vs_human_ages.htm |title=Cat Vs Human Ages |website=www.metpet.com |access-date=2009-06-01}}</ref>

==See also== {{Portal|Energy|Medicine}} {{div col}} *Animal model *Bioenergetics *Energy conversion *Energy quality *Energy transformation *Metabolism {{div col end}}

==References==

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{{Wikiversity|Topic:Biochemistry}}

Category:Human power Category:Measurement Category:Medical terminology Category:Metabolism Category:Units of power Category:Equivalent units