1、Designation: E1619 11 (Reapproved 2016)Standard Test Method forChronic Oral Toxicity Study in Rats1This standard is issued under the fixed designation E1619; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision
2、. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers a long-term study to determinethe effects of a substance in a mammalian species such as therat following pr
3、olonged and repeated oral exposure. Under theconditions of the chronic toxicity test, effects that require along latency period or that are cumulative should becomemanifest.1.2 This test method assumes that the user is knowledgeablein mammalian toxicology and related pertinent areas, and reliesheavi
4、ly on the judgment of the evaluator.1.3 The values stated in SI units are to be regarded as thestandard. The inch-pound units given in parentheses are forinformation only.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility
5、 of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specific hazardstatements, see Section 6.2. Referenced Documents2.1 ASTM Standards:2E609 Terminology Relating to PesticidesE943 Terminology
6、 Relating to Biological Effects and Envi-ronmental Fate2.2 Federal Standards:3Title 40, Code of Federal Regulations (CFR), EnvironmentalProtection Agency, Subchapter E, Pesticide Programs:Part 160, Good Laboratory Practice StandardsTitle 21, Code of Federal Regulations (CFR). Food and DrugAdministra
7、tion, Part 58, Good Laboratory Practice forNonclinical StudiesTitle 40, CFR, Toxic Substance Control Act, Part 792, GoodLaboratory Practice StandardsTitle 40, CFR, Environmental Protection Agency, Part 798,Health Effects Testing Guidelines, Subpart D, ChronicExposure, Chronic Toxicity3. Terminology3
8、.1 DefinitionsSee Terminology E609 and TerminologyE943.3.2 Definitions of Terms Specific to This Standard:3.2.1 chronic toxicity, nthe adverse effects occurring as aresult of the daily exposure of mammalian species to a testsubstance by diet, water, capsule, or gavage for a one-yearperiod.3.2.2 conc
9、entration, nthe weight of test substance per unitweight of the diet (expressed as milligrams per kilogram ofdiet). The weight of test substance per volume of H2O(expressed as milligrams per millilitre of water), or at aconstant rate in the diet (expressed as parts per million).3.2.3 feed effciency,
10、nthis value is a measure of theefficiency with which the animals convert food to body weight.The calculation is the total body weight gain per total foodconsumed.3.2.4 gavage, nforced feeding, as by tube that is passeddown the throat to the stomach.3.2.5 test substance, npesticide or other material(
11、element, chemical compound, formulation, known mixture)administered orally for the purpose of determining chronictoxicity.4. Summary of Test Method44.1 One mammalian species, a rodent, is required; the rat isthe preferred rodent. Forty rats (twenty females and twentymales) are used at each of the fi
12、ve dose levels (control-, low-,two intermediate levels-, and high-dosage groups). If it isdetermined that an interim sacrifice is necessary, the number1This test method is under the jurisdiction of ASTM Committee E50 onEnvironmental Assessment, Risk Management and Corrective Action and is thedirect
13、responsibility of Subcommittee E50.47 on Biological Effects and Environ-mental Fate.Current edition approved Feb. 1, 2016. Published May 2016. Originallyapproved in 1994. Last previous edition approved in 2011 as E1619 11. DOI:10.1520/E1619-11R16.2For referenced ASTM standards, visit the ASTM websit
14、e, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from U.S. Government Publishing Office, 732 N. Capitol St., NW,Washington DC 20401-0001, http:/www.gpo.
15、gov.4Benitz, K. F., “Measurement of Chronic Toxicity,” Methods of Toxicology, ed.G. E. Paget, Blackwell Scientific Publications, Oxford, England, 1970, pp. 32-131.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1should be increased by
16、the number of animals scheduled to besacrificed during the course of the study (see CFR, Title 40,Part 798).4.2 The high-dose level in rats should elicit some signs oftoxicity without causing excessive lethality. The lowest dosagelevel should be one that does not induce any evidence oftoxicity. This
17、 level should be higher (if possible) than thatexpected for human exposure. The intermediate-dosage levelshould produce a minimal observable effect. Whereappropriate, a vehicle control (the volume of which corre-sponds to the volume of vehicle at the highest exposure level)should be used. The select
18、ion of test substance dosages may beestimated from a preliminary 14-day range finding study.4.3 Daily observations of all individual animals for signs oftoxicity and mortality are recorded.4.4 After one year, prior to necropsy, urine, hematology, andblood samples are collected for analysis and then
19、test animalsare sacrificed.4.5 Data collected from treatment and control groups arecompared statistically to detect changes in food or waterconsumption, or both, body weights, organ-to-body weight,and organ-to-brain weight ratios, hematology, and clinicalblood and urine values. Histopathological exa
20、minations arealso performed on selected tissues.5. Significance and Use5.1 This test method should generate data to identify themajority of chronic effects and shall serve to define long-termdose response relationships. In addition the test should allowfor the detection of general toxic effects incl
21、udingneurological, physiological, biochemical, and hematologicaleffects and exposure-related morphological (pathology) effects.5.2 This test method should provide information on targetorgans, the possibilities of accumulation, and may be used forestablishing safety criteria for human exposure. It pr
22、ovidesinformation on potential health hazards likely to arise fromrepeated exposure over a long period of time.6. Hazards6.1 Minimize contact with all test substances and solutionswith appropriate protective clothing, gloves, eye protection,etc. The use of fume hoods and increased ventilation in tes
23、trooms is necessary when handling volatile substances. Infor-mation concerning acute mammalian toxicity and specialhandling procedures should be known before this test methodis used.6.2 Dispose excess test substance, solutions, diets, excreta,and treated animals with consideration for health and env
24、iron-mental safety, and in accordance with all federal, state, andlocal regulations.7. Facilities7.1 No precise physical requirements concerning facilitiesare set forth. However, the animal facility shall meet theestablished standard(s) that may be required by law or regula-tions. It is desirable th
25、at the animal facilities meet the guide-lines suggested by the Institute of Laboratory Resources orfacilities that have been approved by such organizations as theAmerican Association for Accreditation of Laboratory AnimalCare (AAALAC).7.2 EnvironmentHouse test and control animals in cagesdesigned to
26、 hold laboratory animals. Provide for appropriatewater and food consumption. Maintain all animals in atemperature-, humidity-, and light-controlled room. The con-ditions should be 18 to 26C (64.4 to 78.8F) for temperature,40 to 70 % for humidity, and a 12-h light, 12-h dark lightingcycle.8. Test Ani
27、mals8.1 Perform the test with one mammalian species; the rat isthe preferred rodent species. If another mammalian species isused, justification or reasoning for the selection must berecorded.8.2 Obtain rats three weeks post-weaning. The Sprague-Dawley (COBS/CD) rat is an example of a strain frequent
28、lyused. The females should be nulliparious and nonpregnant.Acclimate the animals for a period of no less than seven days.Dosing of rats should begin ideally before six weeks old, butno later than eight weeks of age.8.3 All animals for a given test must come from one sourceand strain and be approxima
29、tely the same age to minimizevariability. Test animals may be obtained from commercialsources or reared in laboratory colonies, but they must not havebeen used in a previous test. Animals should be healthy anddisease free and those that are deformed, injured, emaciated orphenotypically different fro
30、m normal animals must not be usedas test subjects.9. Diets9.1 The preferred administration of test substance is incor-porated into a diet. However, the test substance may beadministered dissolved in drinking water or a solvent, or givenby gavage or capsule for a period of at least twelve months.The
31、choice of route of administration depends upon thephysical and chemical characteristics of the test substance.9.1.1 If the test substance is administered by gavage, a five-day/week dosing regimen is acceptable.9.1.2 When necessary, dissolve or suspend the test sub-stance in a suitable solvent. If a
32、vehicle or diluent is needed, itshould not elicit toxic effects itself nor substantially alter thechemical or toxicological properties of the test substance.9.2 Formulate diets in accordance with the nutrient require-ments of the test species. Any unmedicated commercial dietthat meets the minimum nu
33、tritional standards of the test speciesis acceptable.10. Range-Finding Study10.1 Previous data or a range-finding study should beused/conducted to assist in the selection of the appropriatedoses for the chronic study.10.2 Use groups of six male and six female rats between sixand eight weeks of age.
34、Randomize, number, and place allE1619 11 (2016)2animals in appropriate cages for a five-day acclimation period.During this period, all rats will receive rodent diet minus thetest substance. Dietary levels of the test substance to beadministered may approximate the acute oral LD50dosagesand fractions
35、 thereof (such as 1X, 0.5X, 0.25X, 0.125X,0.0625X, 0.03125X of the LD50). One additional group of eachsex will serve as a solvent or untreated control.10.3 It is strongly recommended that a dietary group beremoved from testing for humane purposes when food con-sumption is markedly reduced. If consum
36、ption as compared tocontrols or acclimation period values, or both, is reduced bymore than 90 %, continued exposure will result in mortality oftest animals in that group.10.4 Base the no-effect and effect levels on the followingparameters: body weight, organ-to-body weight ratios,hematology, clinica
37、l chemistry, gross necropsy, and food orwater consumption, or both, if necessary. Histology on alimited selection of organs may be necessary in some in-stances.10.5 If a lethal dose is not found, set the highest dietarydosage at 1000 mg/kg, since dosage below this value isassumed to be nontoxic.11.
38、Procedure511.1 Select four dosage levels (low, two intermediateconcentrations, and high) plus an untreated or solvent control.Dose all animals by the same method during the entireexperimental period.11.2 Randomize, number, and assign at least 40 rats (20females and 20 males) to each dosage group. If
39、 additionalsacrifices are planned, increase the number of animals by thenumber scheduled to be sacrificed during the course of thestudy.11.3 Administer the test substance (if in the diet or drinkingwater) ad libitum throughout the study and depending on thestability of the test material replace at l
40、east weekly.11.4 Perform chemical analysis of test mixtures (dependingon stability of test substance) at least once on each new batchof test food or water prepared.11.5 Diet PreparationCalculate test substance food mix-tures for the first two weeks using the mean body weights andmean food consumptio
41、n weights computed during the accli-mation period. Thereafter, prepare the mixtures from the meanbody weights and mean food consumption weights computedfrom the first week of the previous two-week period.11.5.1 Compute test substance food-mixture concentrationsfor each dosage using the following for
42、mula:X 5 100K/Gwhere:X = percent of active test substance in the diet (grams of testsubstance/100 g of ground food),K = dosage of substance that is desired and is expressed asgrams of test substance/kilogram of body weight/day,G = amount of food consumed/day over a one-week periodand is expressed as
43、 grams of food consumed perkilogram of body weight/day.Record food consumption (and water if necessary) through-out the study.11.5.2 An alternative to this test method would be todetermine the concentration of test substance in the feed priorto study initiation and then have it remain constant throu
44、ghoutthe study.11.6 ObservationsMake observations of each animal atleast once per day, with appropriate actions taken to minimizeloss of animals to the study (for example, necropsy orrefrigeration of animals found dead and isolation or sacrifice ofweak or moribund animals).11.6.1 Record signs of tox
45、icity (by dosage group and sex) asthey are observed, including time of onset, degree, andduration. These signs include, but are not limited to, changes inskin and fur, eyes and mucous membranes, and alsorespiratory, circulatory, autonomic and central nervoussystems, somatomotor activity, and unusual
46、 behavior patterns.11.6.2 Weigh all animals at least once per week, on the sameday of each week and record weights.11.6.3 Record temperature and humidity continuallythroughout the study.11.6.4 At the end of the one year, sacrifice all survivinganimals.11.7 Clinical ExaminationsMake the following cli
47、nicalexaminations on at least five of each sex in each group of rats.11.7.1 UrinalysisPerform urinalysis at the termination ofthe testing period. Place randomly selected animals in fromeach group and from each sex in metabolism cages for urinecollection. Evaluate each urine sample individually and i
48、ncludethe following measurements: specific gravity, pH, protein,glucose, ketones, bilirubins, urobilinogen, as well as micro-scopic examination of formed elements.11.7.2 HematologyMake the following hematology deter-minations at least twice during the test period on all groups ofanimals including co
49、ncurrent controls (at six months into thestudy and just prior to the terminal sacrifice at the end of thestudy) as follows: hematocrit, hemoglobin concentration,erythrocyte count, total and differential leukocyte counts, and ameasure of clotting potential such as prothrombin time orplatelet count, and reticulocyte count, if signs of anemia arepresent.11.7.3 Blood ChemistryMake clinical biochemical teststhat are considered appropriate to all studies, at least twiceduring the test period on all groups of animals includingconcurrent controls (at six months and just pri
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