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The Carcinogenic Potency Project

Urethane (CAS 51-79-6)
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
tba(B) tba(B) hmo liv lun vsc lun 41.3 16.9m,v

Hamsters: Cancer Test Summary
Hamster Target Sites TD50
Male Female
lgi ski sto adr lgi ski sto thy 65.2m

Monkeys: Cancer Test Summary
Monkey Target Sites TD50
Rhesus Cynomulgus Rhesus Cynomulgus
liv smi vsc lun pan vsc 65.2 52.8

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:   adr = adrenal gland. hmo = hematopoietic system. lgi = large intestine. liv = liver. lun = lung. pan = pancreas. ski = skin. smi = small intestine. sto = stomach. tba = all tumor bearing animals. thy = thyroid gland. vsc = vascular system. (B) = experimental results were reported only for both sexes together. 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.

Urethane: 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

URETHANE (ethyl carbamate) 51-79-6 6441 H f syg wat 90w90 170 0 Toth;ejca,5,165-171;1969 for pam e 44.5mg P<.0005 + 27.9mg 74.7mg 1/67 35/44 der mlc e 74.4mg P<.0005 + 45.2mg 0/62 25/41 cec adp e P<.0005 + 0/55 7/33 vag car e P<.002 1.77gm 0/49 4/20 adr mix e P<.003 + 2.05gm 1/55 7/33 adr coc e P<.0005 1.31gm 0/55 6/33 for car e P<.0005 + 1.23gm 0/62 7/41 thy mix e P<.003 + 2.94gm 0/62 5/41 gal pam e P<.007 8.99gm 0/62 4/41 ova car e P<.007 8.99gm 0/62 4/41 lun ade e 1.36gm P<.2 n.s.s. 0/49 1/20 liv tum e no dre P=1. n.s.s. 0/67 0/44 6442 H f syg wat 55w55 297a 0 Pietra;jnci,25,627-630;1960 for pam e P<.005 + 34.6mg 0/14 4/10 ski mlt e P<.2 80.6mg n.s.s. 0/14 1/10 6443 H m syg wat 24m24 170 0 Toth;ejca,5,165-171;1969 for pam e 64.2mg P<.0005 + 40.5mg 6/88 36/49 der mlc e P<.0005 + 66.7mg 1/62 26/49 for car e P<.0005 + 76.8mg 0/53 18/40 cec adp e P<.009 + 25.2gm 0/53 4/40 liv mix e 1.28gm P<.03 n.s.s. 0/62 3/49 adr coa e P<.2 n.s.s. 1/26 2/12 lun ade e P<.2 n.s.s. 0/26 1/12 6444 H m syg wat 76w76 297a 0 Pietra;jnci,25,627-630;1960 ski mlt e 74.2mg P<.0005 + 29.2mg 1/49 7/10 for pam e 95.8mg P<.0005 + 37.1mg 0/49 6/10 6445 M f b6a orl 73w73 297 0 81.3mg Innes;ntis,1968/1969 lun mix evx 12.5mg P<.0005 + 5.80mg 29.5mg 1/17 17/19 lun ade evx 29.3mg P<.0005 14.0mg 92.3mg 1/17 12/19 --- agm evx 31.7mg P<.0005 15.4mg 79.1mg 0/17 11/19 hag ade evx 59.7mg P<.002 25.5mg 0/17 7/19 liv hpt evx 89.9mg P<.009 33.9mg 2.02gm 0/17 5/19 lun car evx 89.9mg P<.009 33.9mg 2.02gm 0/17 5/19 tba mix evx 9.73mg P<.0005 3.86mg 24.8mg 2/17 18/19 6446 M m b6a orl 72w72 297 0 75.6mg lun mix evx 24.2mg P<.0005 + 11.9mg 76.3mg 2/18 15/22 liv mix evx 26.0mg P<.0005 13.1mg 72.1mg 1/18 14/22 lun ade evx 27.8mg P<.0005 13.4mg 2/18 14/22 hag ade evx 35.8mg P<.0005 17.6mg 90.2mg 0/18 11/22 liv hpt evx 39.0mg P<.002 + 18.2mg 1/18 11/22 --- rts evx 77.9mg P<.006 + 31.6mg 0/18 6/22 tba mix evx 11.2mg P<.0005 5.20mg 27.7mg 3/18 20/22 6447 M f b6c orl 68w68 297 0 81.5mg liv mix evx 32.4mg P<.0005 16.3mg 79.2mg 0/16 12/23 liv hpt evx 55.9mg P<.003 25.1mg 0/16 8/23 lun mix evx 79.0mg P<.009 + 32.1mg 1.76gm 0/16 6/23 lun ade evx 97.4mg P<.02 36.9mg n.s.s. 0/16 5/23 tba mix evx 13.7mg P<.0005 7.21mg 28.0mg 0/16 19/23 6448 M m b6c orl 70w70 297 0 75.7mg liv mix evx 46.0mg P<.002 20.6mg 0/16 8/20 lun mix evx 65.9mg P<.006 + 26.7mg 0/16 6/20 liv hpt evx 81.7mg P<.02 + 30.8mg n.s.s. 0/16 5/20 lun ade evx 81.7mg P<.02 30.8mg n.s.s. 0/16 5/20 tba mix evx 22.4mg P<.0005 11.3mg 51.7mg 0/16 13/20 6449 M m b6c wat 65w70 1933 0 .100mg .500mg 1.00mg 10.0mg Inai;gann,82,380-385;1991 lun a/a aes 5.91mg * P<.0005 3.60mg 10.5mg 9/49 4/49 7/48 8/50 34/50 42/44 lun mix aes 5.91mg * P<.0005 + 3.60mg 10.5mg 9/49 4/49 7/48 8/50 34/50 42/44 liv hem as 63.3mg * P<.0005 + 38.0mg 0/50 0/50 0/50 0/50 2/50 20/50 liv hes as * P<.0005 + 63.2mg 0/50 0/50 0/50 2/50 2/50 11/50 lun a/c aes * P<.0005 98.6mg 0/49 0/49 0/48 0/50 0/50 6/44 hea hes as * P<.0005 2.14gm 0/50 0/50 0/50 0/50 0/50 4/50 liv hpa as 38.2mg Z P<.3 9.92mg n.s.s. 8/50 2/50 8/50 4/50 9/50 (0/50) liv hpc as no dre P=1. n.s.s. 0/50 2/50 1/50 0/50 2/50 0/50 6450 M f cf1 wat 31m31 90 0 20.0mg Tomatis;ijcn,10,489-506;1972 lun tum eg 23.8mg P<.0005 + 13.1mg 59.4mg 13/56 28/40 liv hpt eg no dre P=1. - n.s.s. 2/56 1/40 tba mix eg 23.3mg P<.09 7.51mg n.s.s. 45/56 37/40 6451 M m cf1 wat 29m29 90 0 16.7mg lun tum e 13.2mg P<.0005 + 7.18mg 34.6mg 23/55 40/48 liv hpt e no dre P=1. - 78.0mg n.s.s. 12/55 8/48 tba mix e 12.1mg P<.04 4.11mg n.s.s. 46/55 46/48 6452 M b nmr wat 23m24 298 0 .100mg .500mg 2.50mg 12.5mg Schmahl;ijcn,19,77-80;1977 tba ben ae .434mg Z P<.004 .198mg 3.14mg 2/74 11/65 (12/69 21/59 30/65) tba mal ae 14.7mg * P<.0005 + 8.61mg 32.7mg 6/74 11/65 17/69 21/59 32/65 6453 M b swi eat 27m27 171a 0 Van Esch;fctx,10,373-381;1972 lun ade e 36.1mg P<.0005 + 19.3mg 66.9mg 10/49 46/48 lun adc e 5.06gm P<.3 n.s.s. 0/49 1/48 liv tum e no dre P=1. 1.54gm n.s.s. 0/49 0/48 6454 P b cym eat 5y23 2004 : 0 22.2mg Adamson;ossc,129-156;1982/Thorgeirsson 1994/Dalgard 1997/ Thorgeirsson&Seiber pers.comm. MXB MXB jw 16.4mg P<.004 4.49mg 0/34 3/5 pan adc jw 52.8mg P<.08 + 8.60mg n.s.s. 0/11 1/3 liv hes jw 95.0mg P<.05 + 15.5mg n.s.s. 0/34 1/5 liv hpa jw 31.7mg P<.2 5.16mg n.s.s. 0/3 1/2 lun bro jw 31.7mg P<.2 + 5.16mg n.s.s. 0/3 1/2 tba mal jw 21.5mg P<.2 4.95mg n.s.s. 3/34 3/5 tba mix jw 25.5mg P<.3 5.33mg n.s.s. 4/34 3/5 tba ben jw P<.8 7.96mg n.s.s. 2/20 1/4 6455 P b rhe eat 5y25 2004 : 0 24.4mg MXB MXB jw 44.8mg P<.004 10.1mg 0/42 2/6 jej adc jw 65.2mg P<.04 + 10.6mg n.s.s. 0/25 1/3 adr phe jw P<.04 19.1mg n.s.s. 0/37 1/5 liv hes jw P<.05 + 23.3mg n.s.s. 0/42 1/6 liv hpc jw P<.05 + 23.3mg n.s.s. 0/42 1/6 chp sqp jw 75.5mg P<.2 10.6mg n.s.s. 1/37 1/4 tba mix Wjw 26.3mg P<.2 5.54mg n.s.s. 17/108 4/11 tba mal Wjw 52.9mg P<.3 8.50mg n.s.s. 6/74 2/9 tba ben Wjw 75.9mg P<.6 7.41mg n.s.s. 12/108 2/11 6456 R b sda wat 23m24 298 0 .100mg .500mg 2.50mg 12.5mg Schmahl;ijcn,19,77-80;1977 tba mal ae 41.3mg * P<.0005 + 21.4mg 2/74 2/70 4/65 7/70 15/74 tba ben ae 91.2mg * P<.02 35.6mg n.s.s. 1/74 3/70 2/65 5/70 8/74

Mutagenicity in Salmonella: positive
SMILES Code for Urethane: NC(=O)OCC
InChI Code for Urethane: InChI=1/C3H7NO2/c1-2-6-3(4)5/h2H2,1H3,(H2,4,5)
Source for SMILES and InChI: USEPA Distributed Structure-Searchable Toxicity (DSSTox) Database
Chemical Structure for Urethane: 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.

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Last updated: October 3, 2007

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