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The Carcinogenic Potency Project

Chloroform (CAS 67-66-3)
SMILES, InChI and Structure are below.
Rats and Mice: Cancer Test Summary
Rat Target Sites Mouse Target Sites TD50 (mg/kg/day)
Male Female Male Female Rat Mouse
kid liv kid liv liv 262m 111m,v

Dogs: Cancer Test Summary
Target Sites TD50
(mg/kg/day)
no positive no positive

Key to the Table Above

Positivity: For each chemical with a positive (carcinogenic) experiment in the Carcinogenic Potency Database (CPDB), results are included on carcinogenic potency (TD50) in each species and target sites in males and females. Positivity is determined by an author’s opinion in a published paper. If all experimental results in the CDPB are negative in a sex-species group, “no positive” appears. If the CPDB has no experiments in the sex-species group, “no test” appears. The summary presents the strongest evidence of carcinogenicity in each group. If there are both positive and negative experiments in a sex-species, the negative results are ignored in this Summary Table.
Target Site Codes:   kid = kidney. liv = liver. Target sites are listed if any author of published experimental results concluded that tumors were induced in that organ by the test agent. If there is more than one positive experiment in a sex-species, target sites listed may be from more than one experiment, e.g. if liver and lung are both listed, then liver may have been a target in one experiment and lung in another.
TD50: Our standardized measure of carcinogenic potency, TD50, is the daily dose rate in mg/kg body weight/day to induce tumors in half of test animals that would have remained tumor-free at zero dose. Whenever there is more than one positive experiment in a species, the reported TD50 value is a Harmonic Mean calculated using the TD50 value from the most potent target site in each positive experiment.
Superscripts:   m = There is more than one positive experiment in the species, and TD50 values from each positive experiment are used in the calculation of the reported Harmonic mean of TD50. v = Variation is greater than ten-fold among statistically significant (two-tailed p<0.1) TD50 values from different positive experiments.

The Carcinogenic Potency Database (CPDB) is a unique and widely used international resource of the results of 6540 chronic, long-term animal cancer tests on 1547 chemicals. The CPDB provides easy access to the bioassay literature, with qualitative and quantitative analyses of both positive and negative experiments that have been published over the past 50 years in the general literature through 2001 and by the National Cancer Institute/National Toxicology Program through 2004. The CPDB standardizes the diverse literature of cancer bioassays that vary widely in protocol, histopathological examination and nomenclature, and in the published author’s choices of what information to provide in their papers. Results are reported in the CPDB for tests in rats, mice, hamsters, dogs, and nonhuman primates.

For each experiment, information is included on species, strain, and sex of test animal; features of experimental protocol such as route of administration, duration of dosing, dose level(s) in mg/kg body weight/day, and duration of experiment; experimental results are provided on target organ, tumor type, and tumor incidence; carcinogenic potency (TD50) and its statistical significance; shape of the dose-response, author’s opinion as to carcinogenicity, and literature citation.

Only tests with dosing for at least ¼ the standard lifespan of the species and experiment length at least ½ the lifespan are included in the CPDB. Only routes of administration with whole body exposure are included. Doses are standardized, average dose rates in mg/kg/day. A description of methods used in the CPDB to standardize the diverse literature of animal cancer tests is presented for: 1) Criteria for inclusion of experiments 2) Standardization of average daily dose levels and 3) TD50 estimation for a standard lifespan. See Methods for other details.

TD50 provides a standardized quantitative measure that can be used for comparisons and analyses of many issues in carcinogenesis. The range of TD50 values across chemicals that are rodent carcinogens is more than 100 million-fold. More than half the chemicals tested are positive in at least one experiment.

A plot of all results on each experiment in the CPDB for this chemical is presented below. These results are the source information for the Cancer Test Summary table above.

Chloroform: All Experiments and Citations in CPDB

The definition of each code in the plot below will appear in a pop-up window when the field name in the header line is clicked, e.g., Strain, Site, Path. Each numbered line starts a new experiment and reports protocol information in black. Average daily dose-rates per kg body weight per day are in green. Remaining lines report experimental results in blue.

Abbreviations of fields in header line: # = the line number in the plot of all CPDB chemicals; Xpo = duration of dosing; Xpt = duration of experiment; Site = tissue; Path = tumor type; DR = dose-response; AuOp = author’s opinion about carcinogenicity; LoConf, UpConf = confidence limits (99%) on TD50; Inc = tumor incidence for each dose group.

See Guide to reading the plot for details on each field, using an example of one experiment.

See Help to improve readability, or to fit the plot onto the screen or a printed page.



Chemical (Synonym) CAS
# Species Sex Strain Route Xpo+Xpt PaperNum        0 Dose  1 Dose 2 Dose  3 Dose          Literature Reference or NCI/NTP:Site Path
Site Path Notes   TD50  DR Pval    AuOp LoConf UpConf   Cntrl   1 Inc  2 Inc   3 Inc                                                        Brkly Code

CHLOROFORM 67-66-3 1385 D f beg eat 87m92 1003 0 12.2mg 24.4mg Heywood;jept,2,835-851;1979 liv tum e no dre P=1. - 6.52mg n.s.s. 0/16 0/8 0/8 tba mix e 10.0mg \ P<.3 - 2.22mg n.s.s. 4/16 4/8 (0/8) 1386 D m beg eat 87m92 1003 0 12.2mg 24.4mg liv tum e no dre P=1. - 6.52mg n.s.s. 0/16 0/8 0/8 tba mix e 13.3mg * P<.008 - 5.39mg 230.mg 0/16 4/8 2/8 1387 M f b6c gav 78w92 TR-A : 0 144.mg 289.mg liv hpc v 48.0mg * P<.0005 c 35.2mg 68.0mg 0/20 36/50 39/50 TBA MXB v 54.1mg * P<.0005 37.8mg 91.8mg 2/20 37/50 39/50 liv MXB v 48.0mg * P<.0005 35.2mg 68.0mg 0/20 36/50 39/50 liv:hpa,hpc,nnd. lun MXB v no dre P=1. n.s.s. n.s.s. 0/20 1/50 0/50 lun:a/a,a/c. 1388 M f b6c wat 24m24 1671 0 40.0mg 80.0mg 180.mg 360.mg Jorgenson;faat,5,760-769;1985 liv hpc e 20.2gm * P<.5 - 2.69gm n.s.s. 2/415 7/410 1/142 0/47 1/44 liv hpa e no dre P=1. - 5.18gm n.s.s. 19/415 8/410 8/142 0/47 0/44 liv mix e no dre P=1. - 3.73gm n.s.s. 21/415 15/410 9/142 0/47 1/44 tba mix e no dre P=1. - 664.mg n.s.s. 225/423 217/415 90/142 16/47 24/44 1389 M m b6c gav 78w92 TR-A : 0 83.6mg 168.mg liv hpc v 56.2mg / P<.0005 c 38.7mg 118.mg 1/20 19/50 44/50 TBA MXB v 71.1mg * P<.004 40.4mg 491.mg 4/20 26/50 44/50 liv MXB v 56.2mg / P<.0005 38.7mg 118.mg 1/20 19/50 44/50 liv:hpa,hpc,nnd. lun MXB v no dre P=1. 490.mg n.s.s. 1/20 3/50 2/50 lun:a/a,a/c. 1390 M f bdj inh 24m24 2378 0 7.64mg 44.5mg 131.mg Nagano;apor,741-746;1998/pers.comm. liv mix ev 909.mg * P<.07 + 316.mg n.s.s. 2/50 2/49 4/50 6/48 pit ade ev 2.07gm * P<.7 273.mg n.s.s. 5/50 9/49 13/50 8/48 liv hpc ev 2.67gm * P<.3 + 611.mg n.s.s. 1/50 1/49 0/50 3/48 lun tum ev no dre P=1. 62.8mg n.s.s. 0/50 0/49 0/50 0/48 1391 M m bdj inh 24m24 2378 0 6.37mg 37.1mg 109.mg kid mix ev 226.mg * P<.0005 + 133.mg 477.mg 0/50 1/50 7/50 12/48 kid rcc ev 287.mg * P<.0005 + 160.mg 674.mg 0/50 1/50 4/50 11/48 liv mix ev 402.mg * P<.09 145.mg n.s.s. 14/50 7/50 12/50 17/48 kid rca ev 1.25gm * P<.2 + 432.mg n.s.s. 0/50 0/50 3/50 1/48 lun a/c ev 3.53gm * P<.7 461.mg n.s.s. 3/50 3/50 1/50 4/48 lun a/a ev no dre P=1. 658.mg n.s.s. 3/50 3/50 2/50 2/48 1392 M m c5l gav 19m24 710m 0 39.6mg Roe;jept,2,799-819;1979 lun mix e 728.mg P<.5 - 134.mg n.s.s. 2/46 4/51 liv tum e no dre P=1. - 416.mg n.s.s. 2/46 0/51 tba mix e no dre P=1. - 112.mg n.s.s. 16/46 13/51 1393 M m cba gav 19m24 710m 0 39.6mg liv mix e no dre P=1. - 70.7mg n.s.s. 37/51 29/51 lun mix e no dre P=1. - 155.mg n.s.s. 13/51 8/51 tba mix e no dre P=1. - 64.7mg n.s.s. 42/51 33/51 1394 M m cf1 gav 80w93 710m 0 44.2mg lun mix e 376.mg P<.6 - 64.2mg n.s.s. 9/45 12/48 liv tum e 1.43gm P<.9 - 111.mg n.s.s. 4/45 5/48 tba mix e 140.mg P<.4 - 37.2mg n.s.s. 16/45 22/48 1395 M m cfl gav 19m24 710m 0 39.6mg kid mix e 153.mg P<.0005 + 66.6mg 613.mg 6/240 9/49 lun tum e 4.35gm P<1. - 65.8mg n.s.s. 102/240 21/49 liv tum e no dre P=1. - 189.mg n.s.s. 69/240 8/49 tba mix e no dre P=1. 68.4mg n.s.s. 170/240 30/49 1396 M f ici gav 80w96 710m 0 12.1mg 42.9mg lun tum e 316.mg * P<.3 - 81.3mg n.s.s. 5/59 2/35 6/38 liv tum e no dre P=1. - 59.2mg n.s.s. 1/59 0/35 0/38 tba mix e no dre P=1. - 71.5mg n.s.s. 29/59 10/35 15/38 1397 M m ici gav 80w96 710m 0 12.1mg 42.9mg kid mix e 139.mg * P<.0005 + 62.8mg 407.mg 0/72 0/37 8/38 liv tum e 324.mg * P<.4 - 73.5mg n.s.s. 5/72 6/37 5/38 lun tum e 9.83gm * P<1. - 95.4mg n.s.s. 7/72 7/37 4/38 tba mix e 45.4mg * P<.006 21.0mg 643.mg 20/72 20/37 21/38 1398 M m ici gav 80w98 710n 0 42.0mg kid mix e 278.mg P<.08 + 91.2mg n.s.s. 1/49 5/47 lun mix e 336.mg P<.3 - 83.7mg n.s.s. 4/49 7/47 liv mix e 437.mg P<.6 - 78.3mg n.s.s. 7/49 9/47 tba mix e 88.5mg P<.2 31.8mg n.s.s. 17/49 24/47 1399 M m ici gav 80w98 710o 0 42.0mg kid mix e 95.5mg P<.0005 + 47.1mg 325.mg 1/50 12/48 liv mix e no dre P=1. - 105.mg n.s.s. 9/50 8/48 lun mix e no dre P=1. - 182.mg n.s.s. 5/50 3/48 tba mix e no dre P=1. 66.8mg n.s.s. 24/50 20/48 1400 R f osm gav 18m26 TR-A : 0 50.2mg 100.mg thy MXA v# 126.mg * P<.004 - 65.8mg 936.mg 1/20 8/50 11/50 thy:cca,ccr,fca,fcc. S TBA MXB v 68.2mg * P<.05 28.8mg n.s.s. 12/20 24/50 25/50 liv MXB v 1.13gm * P<.7 156.mg n.s.s. 2/20 4/50 3/50 liv:hpa,hpc,nnd. 1401 R m osm gav 18m26 TR-A : 0 45.2mg 90.3mg kid MXA 119.mg / P<.0005 c 65.5mg 334.mg 0/20 4/50 12/50 kid:tla,uac. TBA MXB 194.mg * P<.5 43.5mg n.s.s. 9/20 24/50 20/50 liv MXB 455.mg * P<.08 157.mg n.s.s. 0/20 1/50 3/50 liv:hpa,hpc,nnd. 1402 R m osm wat 24m24 1671 0 10.0mg 20.0mg 45.0mg 90.0mg Jorgenson;faat,5,760-769;1985 kid mix e 519.mg * P<.0005 + 265.mg 1.79gm 5/301 6/313 7/148 3/48 7/50 kid mix e 606.mg * P<.0005 305.mg 1.97gm 4/301 4/313 4/148 3/48 7/50 kid tla e 972.mg * P<.002 420.mg 6.25gm 4/301 2/313 3/148 2/48 5/50 --- nfm e 2.20gm * P<.04 676.mg n.s.s. 2/303 2/316 1/148 0/48 3/50 --- mix e 1.36gm * P<.3 343.mg n.s.s. 5/303 19/316 5/148 2/48 3/50 tba mix e 1.97gm * P<.9 90.2mg n.s.s. 212/303 227/316 105/148 38/48 34/50 1403 R f f3d inh 24m24 2378 0 3.64mg 10.9mg 32.7mg Nagano;apor,741-746;1998/pers.comm. kid rca e 1.59gm * P<.2 - 258.mg n.s.s. 0/50 0/50 0/50 1/49 kid tcc e 1.59gm * P<.2 - 258.mg n.s.s. 0/50 0/50 0/50 1/49 liv hpa e 2.18gm * P<.8 - 191.mg n.s.s. 1/50 0/50 2/50 1/49 1404 R m f3d inh 24m24 2378 0 2.55mg 7.64mg 22.9mg kid tum e no dre P=1. - 18.2mg n.s.s. 0/50 0/50 0/50 0/50 liv mix e no dre P=1. - 18.2mg n.s.s. 0/50 0/50 0/50 0/50 1405 R f sda gav 80w95 711 0 43.3mg Palmer;jept,2,821-833;1979 liv cye e 1.20gm P<.3 - 196.mg n.s.s. 0/50 1/49 tba mix e 78.3mg P<.2 - 27.1mg n.s.s. 22/50 29/49 tba mal e 276.mg P<.2 - 86.0mg n.s.s. 2/50 6/49 1406 R m sda gav 80w95 711 0 43.3mg liv tum e no dre P=1. - 365.mg n.s.s. 0/48 0/49 tba mix e no dre P=1. - 115.mg n.s.s. 12/48 9/49 tba mal e no dre P=1. - 195.mg n.s.s. 6/48 3/49 1407 R f wis wat 43m43 1681 0 115.mg Tumasonis;eaes,9,233-240;1985 liv nnd ev 883.mg P<.005 + 429.mg 5.42gm 0/18 10/40 liv hpc ev 10.0gm P<.4 1.63gm n.s.s. 0/18 1/40 kid tum ev no dre P=1. 3.06gm n.s.s. 0/18 0/40 1408 R m wis wat 40m40 1681 0 103.mg kid adc ev 5.30gm P<.3 + 862.mg n.s.s. 0/22 1/28 kid ade ev 5.30gm P<.3 + 862.mg n.s.s. 0/22 1/28 liv hpc ev 5.30gm P<.3 862.mg n.s.s. 0/22 1/28 liv nnd ev no dre P=1. 574.mg n.s.s. 5/22 5/28

Mutagenicity in Salmonella: negative
SMILES Code for Chloroform: ClC(Cl)Cl
InChI Code for Chloroform: InChI=1/CHCl3/c2-1(3)4/h1H
Source for SMILES and InChI: USEPA Distributed Structure-Searchable Toxicity (DSSTox) Database
Chemical Structure for Chloroform: Chemical Structure
Source for structure: National Library of Medicine ChemIDPlus

See full CPDB Summary Table on 1547 chemicals. See Full CPDB for all results on 6540 experiments of 1547 chemicals.

A complete list of CPDB chemicals, which is searchable by name or by CAS number, is available here.

For a compendium of CPDB results organized by target organ, which lists all chemicals in each species that induced tumors in each of 35 organs, see Summary Table by Target Organ.

The CPDB is available in several formats that permit printing and downloading into spreadsheets and statistical databases.

  1. A plot of the CPDB presents results of 1547 experiments on 6540 chemicals in an easily readable format that has been used in publications of the CPDB.
  2. A Screen version plot for use on a single computer screen, with the same data.
  3. Excel version of the same data.
  4. Tab-separated versions of the same data, which can be easily read into databases.

A Supplementary Dataset gives details on dosing and survival for each experiment.

Relatively precise estimates of the lower confidence limit on the TD10 (LTD10) are readily calculated from the TD50 and its lower confidence limit, which are reported in the CPDB. For researchers and regulatory agencies interested in LTD10 values, we provide them in an Excel spreadsheet.

PDF versions of our publications of analyses using the CPDB are available, organized by year and by research topic.


Carcinogenic Potency Database Project (CPDB) Home Page
For more information about this Web Page, contact Specialized Information Services (tehip@teh.nlm.nih.gov).
Last updated: October 3, 2007


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