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The Carcinogenic Potency Project

Chloroprene (>96% chloroprene) (CAS 126-99-8)
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 lun orc thy kid mgl orc thy hag kid lun sto vsc ezy hag liv lun mgl per sto sub vsc 12.5m 8.17m

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:   ezy = ear/Zymbal’s gland. hag = harderian gland. kid = kidney. liv = liver. lun = lung. mgl = mammary gland. orc = oral cavity (includes tissues of the mouth, oropharynx, pharynx, and larynx). per = peritoneal cavity. sto = stomach. sub = subcutaneous tissue. thy = thyroid gland. vsc = vascular system. 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.

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.

Chloroprene (>96% chloroprene): 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


CHLOROPRENE (>96% CHLOROPRENE)   126-99-8
1442 M f b6c inh 24m24 TR467 :                       0    14.6mg  36.4mg  91.1mg
 MXB MXB        4.00mg Z P<.0005    2.58mg 6.74mg  28/50   43/50   47/50  (48/50)  ---:hem,hes; for:sqc,sqp; hag:ade,car; liv:hpa,
                                                                         hpc; lun:a/a,a/c; mey:sar; mgl:ade,car; sub:sar; zym:car. C
 lun MXA        5.36mg Z P<.0005 c  3.45mg 8.68mg   4/50   28/50   34/50  (42/50)                                     lun:a/a,a/c.
 liv MXA        7.07mg Z P<.0005 c  4.03mg 15.4mg  20/50   26/50   20/50  (30/50)                                     liv:hpa,hpc.
 lun a/a        8.65mg Z P<.0005 c  5.29mg 14.7mg   2/50   16/50   29/50  (26/50)
 lun a/c        14.6mg * P<.0005 c  9.17mg 24.6mg   2/50   14/50   16/50   28/50
 liv hpc        15.2mg Z P<.0005 c  7.94mg 35.2mg   4/50   11/50   14/50  (19/50)
 liv hpa        19.8mg * P<.0005    10.5mg 51.3mg  17/50   19/50   11/50   16/50                                                   S
 --- MXA        21.5mg Z P<.0005 c  10.6mg 52.2mg   4/50    6/50   18/50   (8/50)                                     ---:hem,hes.
 --- hes        22.2mg Z P<.0005 c  10.8mg 55.9mg   4/50    6/50   17/50   (5/50)
 mey MXA        25.9mg Z P<.0005    12.7mg 53.4mg   0/50    4/50   15/50   (5/50)                                     mey:hem,hes. S
 sub sar        28.9mg * P<.0005 c  17.1mg 49.5mg   0/50   11/50   11/50   18/50
 mey hes        32.2mg Z P<.0005    15.5mg 67.1mg   0/50    4/50   13/50   (4/50)                                                  S
 mey sar        40.0mg Z P<.0005 c  17.5mg 98.8mg   0/50    4/50    8/50   (3/50)
 hag MXA        55.2mg * P<.0005 c  22.6mg 208.mg   2/50    5/50    3/50    9/50                                      hag:ade,car.
 hag ade        61.3mg * P<.0005 c  24.1mg 231.mg   1/50    3/50    3/50    8/50
 mgl MXA        65.6mg * P<.0005 c  29.4mg 199.mg   3/50    5/50    8/50   12/50                                      mgl:ade,car.
 pit pda        68.1mg * P<.006     26.0mg 1.13gm   4/50    6/50    4/50    4/50                                                   S
 mgl car        75.3mg * P<.0005 c  32.9mg 233.mg   3/50    4/50    7/50   12/50
 --- hem        134.mg * P<.0005 c  38.8mg 793.mg   0/50    0/50    2/50    3/50
 for MXA        332.mg * P<.01   c  74.2mg 65.9gm   1/50    0/50    0/50    4/50                                      for:sqc,sqp.
 zym car        864.mg * P<.01   c  259.mg 68.6gm   0/50    0/50    0/50    3/50
 ute esp        133.mg * P<.04      38.3mg n.s.s.   2/50    4/50    2/50    3/50                                                   S
 TBA MXB        3.92mg Z P<.0005    2.54mg 6.62mg  34/50   47/50   50/50  (48/50)
 liv MXB        7.07mg Z P<.0005    4.03mg 15.4mg  20/50   26/50   20/50  (30/50)                                 liv:hpa,hpb,hpc.
 lun MXB        5.36mg Z P<.0005    3.45mg 8.68mg   4/50   28/50   34/50  (42/50)                                     lun:a/a,a/c.
1443 M m b6c inh 24m24 TR467 :                       0    12.1mg  30.4mg  75.9mg
 MXB MXB        8.68mg Z P<.0005    5.45mg 17.3mg  16/50   33/50   44/50  (48/50)  ---:hem,hes; for:sqc,sqp; hag:ade,anb,car; lun:
                                                                                                                          a/a,a/c. C
 lun MXA        17.2mg * P<.0005 c  11.0mg 31.9mg  13/50   28/50   36/50   43/50                                      lun:a/a,a/c.
 --- MXA        17.9mg Z P<.0005 c  11.1mg 35.5mg   3/50   14/50   23/50  (21/50)                                     ---:hem,hes.
 --- hes        19.1mg Z P<.0005 c  11.7mg 39.0mg   3/50   13/50   22/50  (19/50)
 liv MXA        19.5mg Z P<.0005    10.4mg 79.1mg  24/50   29/50   39/50  (34/50)                                     liv:hpb,hpc. S
 --- MXA        21.3mg Z P<.0005 c  13.2mg 41.6mg   1/50   12/50   18/50  (17/50)                                     ---:hem,hes.
 liv hpc        21.6mg Z P<.002     11.1mg 112.mg  24/50   28/50   37/50  (33/50)                                                  S
 --- hes        23.8mg Z P<.0005 c  14.3mg 49.6mg   1/50   11/50   16/50  (15/50)
 lun a/c        26.4mg * P<.0005 c  16.8mg 50.0mg   6/50   12/50   23/50   28/50
 lun a/a        30.7mg * P<.0005 c  18.4mg 67.9mg   8/50   18/50   22/50   28/50
 mey MXA        37.6mg Z P<.0005    20.7mg 76.6mg   0/50    3/50   14/50   (9/50)                                     mey:hem,hes. S
 mey hes        39.0mg Z P<.0005    21.2mg 81.4mg   0/50    3/50   13/50   (7/50)                                                  S
 liv MXA        39.9mg * P<.009     18.6mg 1.05gm  43/50   38/50   43/50   42/50                                  liv:hpa,hpb,hpc. S
 hag MXA        60.9mg * P<.0005 c  33.3mg 172.mg   2/50    5/50   10/50   12/50                                  hag:ade,anb,car.
 hag MXA        79.5mg * P<.0005 c  40.4mg 309.mg   2/50    5/50    8/50   10/50                                      hag:ade,anb.
 liv hes        123.mg * P<.005     55.7mg 1.30gm   2/50    5/50    6/50    8/50                                                   S
 sub hes        177.mg * P<.006     73.5mg 2.71gm   1/50    4/50    1/50    7/50                                                   S
 for MXA        291.mg * P<.008  c  108.mg 7.29gm   1/50    0/50    2/50    5/50                                      for:sqc,sqp.
 liv MXA        42.5mg * P<.02      19.4mg n.s.s.  43/50   37/50   42/50   41/50                                      liv:hpa,hpc. S
 liv hpa        71.9mg * P<.03      30.1mg n.s.s.  22/50   16/50   19/50   21/50                                                   S
 kid rua        301.mg * P<.02      108.mg n.s.s.   0/50    1/50    1/50    3/50                                                   S
 for sqp        335.mg * P<.02   c  114.mg n.s.s.   1/50    0/50    2/50    4/50
 TBA MXB        28.4mg * P<.003     14.2mg 182.mg  48/50   48/50   50/50   50/50
 liv MXB        39.9mg * P<.009     18.6mg 1.05gm  43/50   38/50   43/50   42/50                                  liv:hpa,hpb,hpc.
 lun MXB        17.2mg * P<.0005    11.0mg 31.9mg  13/50   28/50   36/50   43/50                                      lun:a/a,a/c.
1444 M m b6c inh 24m24 TR467 with step               0    12.1mg  30.4mg  75.9mg
 kid rua        129.mg * P<.0005 c  65.9mg 327.mg   0/50    2/50    3/50    9/50
1445 R f f34 inh 24m24 TR467 :                       0    3.47mg  8.67mg  21.7mg
 cli MXA        7.14mg Z P<.007     3.30mg 99.4mg   2/50   12/50   (5/50    3/50)                             cli:ade,anb,car,cnb. S
 cli MXA        12.4mg Z P<.005     5.01mg 102.mg   0/50    6/50   (4/50    2/50)                                     cli:car,cnb. S
 ton MXA        32.9mg * P<.0005    18.5mg 83.7mg   0/50    3/50    3/50   11/50                                      ton:sqc,sqp. S
 MXA MXA        33.9mg * P<.0005 c  17.9mg 118.mg   1/50    3/50    5/50   11/50       gnv:sqp; orm:sqp; phr:sqc,sqp; ton:sqc,sqp.
 ton sqp        53.5mg * P<.002     25.9mg 230.mg   0/50    2/50    1/50    7/50                                                   S
 MXA sqp        61.2mg * P<.007  c  26.5mg 991.mg   1/50    2/50    2/50    7/50               gnv:sqp; orm:sqp; phr:sqp; ton:sqp.
 MXA sqc        77.8mg * P<.009  c  34.8mg 2.24gm   0/50    1/50    3/50    4/50                                 phr:sqc; ton:sqc.
 ton sqc        91.1mg * P<.01      38.8mg 6.01gm   0/50    1/50    2/50    4/50                                                   S
 mgl fba        16.3mg * P<.03   c  7.18mg n.s.s.  24/50   32/50   36/50   36/50
 mgl MXA        20.4mg * P<.07   c  7.90mg n.s.s.  28/50   34/50   36/50   36/50                                      mgl:car,fba.
 --- mnl        30.4mg * P<.04      12.3mg n.s.s.  18/50   18/50   20/50   26/50                                                   S
 thy MXA        113.mg * P<.03   c  41.2mg n.s.s.   1/50    1/50    1/50    5/50                                      thy:fca,fcc.
 kid rua        461.mg * P<.06      113.mg n.s.s.   0/50    0/50    0/50    2/50
 ubl tcc        467.mg * P<.06   e  115.mg n.s.s.   0/50    0/50    0/50    2/50
 MXB MXB        23.3mg * P<.2       8.31mg n.s.s.  30/50   35/50   36/50   36/50  gnv:sqp; mgl:car,fba; orm:sqp; phr:sqc,sqp; thy:
                                                                                                             fca,fcc; ton:sqc,sqp. C
 lun a/a        279.mg * P<.2    e  70.2mg n.s.s.   1/50    0/50    0/50    3/50
 TBA MXB        25.4mg * P<.3       7.49mg n.s.s.  47/50   50/50   50/50   49/50
 liv MXB        no dre   P=1.       n.s.s. n.s.s.   0/50    0/50    0/50    0/50                                  liv:hpa,hpb,hpc.
1446 R f f34 inh 24m24 TR467 with step               0    3.47mg  8.67mg  21.7mg
 kid rua        183.mg * P<.006     61.4mg 1.92gm   0/50    0/50    0/50    4/50                                                   S
 kid MXA        183.mg * P<.006  c  61.4mg 1.92gm   0/50    0/50    0/50    4/50                                      kid:rua,ruc.
1447 R m f34 inh 24m24 TR467 :                       0    2.43mg  6.07mg  15.2mg
 MXB MXB        5.79mg * P<.0005    3.09mg 13.6mg   2/50    5/50   11/50   18/50  gnv:sqp; lun:a/a,a/c; orm:sqp; phr:sqp; thy:fca,
                                                                                                                 fcc; ton:sqc,sqp. C
 MXA MXA        10.1mg * P<.0005 c  5.13mg 21.9mg   0/50    2/50    5/50   12/50           gnv:sqp; orm:sqp; phr:sqp; ton:sqc,sqp.
 MXA sqp        11.1mg * P<.0005 c  5.41mg 27.3mg   0/50    2/50    4/50   10/50               gnv:sqp; orm:sqp; phr:sqp; ton:sqp.
 ton MXA        13.6mg * P<.0005    6.02mg 35.9mg   0/50    0/50    4/50    8/50                                      ton:sqc,sqp. S
 ton sqp        15.6mg * P<.0005    6.39mg 50.6mg   0/50    0/50    3/50    6/50                                                   S
 thy MXA        18.7mg * P<.003  c  7.52mg 134.mg   0/50    2/50    4/50    5/50                                      thy:fca,fcc.
 thy fca        22.0mg * P<.009     7.98mg 1.25gm   0/50    2/50    2/50    4/50                                                   S
 lun a/c        24.5mg * P<.009  c  9.02mg 961.mg   0/50    2/50    1/50    4/50
 --- msm        27.1mg * P<.008     11.6mg 575.mg   0/50    1/50    5/50    3/50                                                   S
 thy cca        20.0mg * P<.05      6.72mg n.s.s.   3/50    6/50    4/50    7/50                                                   S
 lun MXA        23.8mg * P<.02   c  8.34mg n.s.s.   2/50    2/50    4/50    6/50                                      lun:a/a,a/c.
 kid rua        38.9mg * P<.05      12.4mg n.s.s.   0/50    1/50    1/50    2/50                                                   S
 MXA sqp        39.2mg * P<.02      15.3mg n.s.s.   0/50    2/50    1/50    4/50                        gnv:sqp; orm:sqp; phr:sqp. S
 ubl tcc        99.9mg * P<.4    e  16.3mg n.s.s.   0/50    0/50    1/50    0/50
 ubl tpp        468.mg * P<.2    e  76.2mg n.s.s.   0/50    0/50    0/50    1/50
 TBA MXB        6.12mg * P<.04      2.52mg n.s.s.  50/50   50/50   50/50   50/50
 liv MXB        no dre   P=1.       n.s.s. n.s.s.   0/50    0/50    0/50    0/50                                  liv:hpa,hpb,hpc.
1448 R m f34 inh 24m24 TR467 with step               0    2.43mg  6.07mg  15.2mg
 kid rua        15.4mg * P<.008  c  6.18mg 462.mg   1/50    7/50    6/50    8/50
 kid MXA        16.1mg * P<.02      6.26mg n.s.s.   1/50    8/50    6/50    8/50                                      kid:rua,ruc. S
Mutagenicity in Salmonella: negative
SMILES Code for Chloroprene (>96% chloroprene): C=C(Cl)C=C
InChI Code for Chloroprene (>96% chloroprene): InChI=1/C4H5Cl/c1-3-4(2)5/h3H,1-2H2
Source for SMILES and InChI: USEPA Distributed Structure-Searchable Toxicity (DSSTox) Database
Chemical Structure for Chloroprene (>96% chloroprene): 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 (support@leadscope.com).
Last updated: October 3, 2007


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