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The Carcinogenic Potency Project

Formaldehyde (CAS 50-00-0)
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
hmo nas hmo nas nas no positive 1.35m,v 43.9

Hamsters: Cancer Test Summary
Hamster Target Sites TD50
Male Female
no positive no test 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:   hmo = hematopoietic system. nas = nasal cavity (includes tissues of the nose, nasal turbinates, paranasal sinuses and trachea). 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.

Formaldehyde: 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

FORMALDEHYDE 50-00-0 2890 H m syg inh 94w94 1414m 0 .772mg Dalbey;txcy,24,9-14;1982 res tum r no dre P=1. - 6.50mg n.s.s. 0/50 0/50 2891 H m syg inh 25m25 1414n 0 1.29mg res tum rs no dre P=1. - 25.6mg n.s.s. 0/132 0/88 2892 M f b6c inh 52w52 1566a 0 .772mg 2.32mg 5.79mg Pavkov;ciit;1981/Kerns 1983 nas tum ek no dre P=1. .271mg n.s.s. 0/10 0/10 0/10 0/10 lun tum ek no dre P=1. 2.98mg n.s.s. 0/10 0/10 liv tum ek no dre P=1. 2.98mg n.s.s. 0/10 0/10 2893 M f b6c inh 78w78 1566b 0 .772mg 2.32mg 5.79mg nas tum ek no dre P=1. 1.21mg n.s.s. 0/20 0/20 0/20 0/19 liv mix ek no dre P=1. 8.42mg n.s.s. 2/20 1/19 lun tum ek no dre P=1. 12.8mg n.s.s. 0/20 0/19 2894 M f b6c inh 24m24 1566c 0 5.79mg lun mix ek 47.3mg P<.3 10.9mg n.s.s. 1/30 3/27 liv mix ek 98.7mg P<.6 14.4mg n.s.s. 1/30 2/28 nas tum ek no dre P=1. 3.10mg n.s.s. 0/30 0/26 0/41 0/28 2895 M f b6c inh 24m27 1566m 0 .686mg 2.06mg 5.15mg nas tum e no dre P=1. 6.06mg n.s.s. 0/50 0/54 0/39 0/54 lun mix e no dre P=1. 44.5mg n.s.s. 1/50 1/54 liv tum e no dre P=1. 72.5mg n.s.s. 0/50 0/54 2896 M m b6c inh 52w52 1566a 0 4.83mg liv hpc ek 7.85mg P<.3 1.28mg n.s.s. 0/10 1/10 lun tum ek no dre P=1. 2.49mg n.s.s. 0/10 0/10 nas tum ek no dre P=1. .226mg n.s.s. 0/10 0/10 0/10 0/10 2897 M m b6c inh 24m24 1566c 0 .644mg 1.93mg 4.83mg ntu sqc es 43.9mg * P<.04 + 10.8mg n.s.s. 0/20 0/22 0/19 2/17 liv mix es 34.5mg P<.2 9.67mg n.s.s. 4/62 6/40 lun mix es no dre P=1. 6.53mg n.s.s. 6/25 4/18 2898 R f f34 inh 52w52 1566n 0 .184mg .552mg 1.38mg nas tum ek no dre P=1. 64.6ug n.s.s. 0/10 0/10 0/10 0/10 liv tum ek no dre P=1. .710mg n.s.s. 0/10 0/10 2899 R f f34 inh 78w78 1566o 0 .184mg .552mg 1.38mg ntu sqc ek 3.67mg * P<.005 + 1.27mg 33.9mg 0/20 0/20 0/20 4/19 liv nnd ek P<1. 1.81mg n.s.s. 1/20 1/19 ntu pla ek no dre P=1. 3.23mg n.s.s. 0/20 1/20 0/20 0/19 2900 R f f34 inh 25m25 1566r : 0 .184mg .552mg 1.38mg ntu sqc s 1.37mg Z P<.0005 + .952mg 2.06mg 0/78 0/79 1/76 48/73 ntu pla s 7.95mg Z P<.4 1.25mg n.s.s. 0/78 3/79 0/76 1/73 liv nnd es no dre P=1. 4.13mg n.s.s. 1/67 0/14 2901 R m f34 inh 52w52 1566n 0 .129mg .386mg .965mg nas tum ek no dre P=1. 45.2ug n.s.s. 0/10 0/10 0/10 0/10 liv tum ek no dre P=1. .497mg n.s.s. 0/10 0/10 2902 R m f34 inh 78w78 1566o 0 .129mg .386mg .965mg ntu sqc ek 2.57mg * P<.005 + .886mg 23.8mg 0/20 0/20 0/20 4/19 ntu pla ek 5.39mg * P<.2 1.32mg n.s.s. 0/20 0/20 1/20 1/19 liv tum ek no dre P=1. 2.24mg n.s.s. 0/20 0/20 2903 R m f34 inh 24m24 1566r : 0 .129mg .386mg .965mg ntu sqc s .798mg Z P<.0005 + .510mg 1.23mg 0/79 0/80 1/79 47/73 ntu pla s 3.01mg * P<.03 1.10mg n.s.s. 1/79 4/80 5/79 3/73 liv mix es no dre P=1. 2.85mg n.s.s. 4/74 1/22 2904 R m f34 inh 52w52 2279m : 0 45.0ug .129mg .386mg .643mg .965mg Monticello;canr,56,1012-1022;1996/ CIIT 1999/pers.comm. nas sqc Ckr 2.37mg * P<.06 .582mg n.s.s. 0/12 0/12 0/12 0/12 0/10 2/16 2905 R m f34 inh 80w80 2279n : 0 45.0ug .129mg .386mg .643mg .965mg nas sqc Ckr .895mg * P<.0005 + .422mg 2.61mg 0/10 0/11 0/12 0/12 3/10 6/11 2906 R m f34 inh 24m24 2279o : 0 45.0ug .129mg .386mg .643mg .965mg nas sqc Cr .480mg Z P<.0005 + .357mg .656mg 0/46 0/48 0/48 1/48 19/47 71/97 2907 R m f3d inh 52w52 2445m 0 19.3ug .129mg .965mg Kamata;jtxs,22,239-254;1997/pers.comm. nas tum ek no dre P=1. 4.25ug n.s.s. 0/5 0/5 0/5 0/5 2908 R m f3d inh 78w78 2445n 0 19.3ug .129mg .965mg nas mix ek .874mg * P<.02 .210mg n.s.s. 0/5 0/5 0/5 2/5 2909 R m f3d inh 27m28 2445o 0 19.3ug .129mg .965mg nas mix ae .980mg * P<.0005 + .512mg 2.17mg 0/22 0/22 0/22 14/20 nas sqc ae 1.24mg * P<.0005 + .628mg 2.94mg 0/22 0/22 0/22 12/20 nas sqp ae 10.0mg * P<.03 2.46mg n.s.s. 0/22 0/22 0/22 2/20 2910 R f sda wat 24m34 BT7001 0 .410mg 2.05mg 4.10mg 20.5mg 41.0mg 61.5mg Soffritti;txih,5,699-730; 1989 --- leu er * P<.04 + n.s.s. 3/50 2/50 4/50 4/50 4/50 7/50 7/50 --- lls er * P<.03 + n.s.s. 1/50 1/50 3/50 2/50 2/50 5/50 5/50 git mix er 2.96gm * P<.2 + n.s.s. 0/50 1/50 2/50 0/50 0/50 1/50 3/50 2911 R f sda inh 24m24 2205 0 1.14mg Holmstrom;acot,108,274-283;1989 nac sqc er 12.1mg P<.3 1.97mg n.s.s. 0/15 1/16 2912 R m sda wat 24m34 BT7001 0 .359mg 1.79mg 3.59mg 17.9mg 35.9mg 53.8mg Soffritti;txih,5,699-730; 1989 --- lls er * P<.0005 + 1.73gm 4/50 0/50 2/50 4/50 4/50 6/50 11/50 --- leu er * P<.01 + 63.8gm 5/50 1/50 5/50 5/50 8/50 6/50 11/50 git mix er 1.41gm * P<.02 + n.s.s. 0/50 2/50 0/50 0/50 0/50 1/50 5/50 2913 R m sda inh 28m28 1674 0 .952mg Sellakumar;txap,81,401-406;1985 nac sqc e 1.82mg P<.0005 + 1.22mg 2.86mg 0/99 38/100 nac car e 86.4mg P<.3 + 14.1mg n.s.s. 0/99 1/100 nac fbs e 86.4mg P<.3 + 14.1mg n.s.s. 0/99 1/100 liv hpc e no dre P=1. 16.0mg n.s.s. 1/99 1/100 2914 R f wal wat 24m24 1918 0 1.80mg 21.0mg Til;fctx,27,77-87;1989 for exp e no dre P=1. - 16.7mg n.s.s. 1/48 0/49 0/47 0/48 stg tum e no dre P=1. - 16.7mg n.s.s. 0/48 0/49 0/47 0/48 liv hpc no dre P=1. - 17.2mg n.s.s. 0/50 0/50 0/50 0/50 pit het no dre P=1. - n.s.s. 6/50 11/50 3/50 7/50 tba mix no dre P=1. - n.s.s. 37/50 38/50 32/50 34/50 tba ben no dre P=1. - n.s.s. 34/50 37/50 25/50 32/50 tba mal no dre P=1. - n.s.s. 9/50 9/50 7/50 7/50 2915 R m wal wat 24m24 1918 0 1.20mg 15.0mg 82.0mg stg tum e no dre P=1. - 10.4mg n.s.s. 0/47 0/45 0/44 0/47 for exp e no dre P=1. - n.s.s. 0/47 1/45 0/44 0/47 liv hpc no dre P=1. - n.s.s. 0/50 1/50 0/50 0/50 tba mix no dre P=1. - n.s.s. 33/50 27/50 30/50 24/50 tba ben no dre P=1. - n.s.s. 28/50 22/50 26/50 18/50 tba mal no dre P=1. - n.s.s. 8/50 6/50 8/50 7/50 2916 R m wal inh 28m29 1926 0 6.21ug 62.1ug .621mg Woutersen;japt,9,39-46;1989 nac sqc r 42.9mg * P<.7 - 4.83mg n.s.s. 0/30 1/30 1/30 1/30

Mutagenicity in Salmonella: positive
SMILES Code for Formaldehyde: C=O
InChI Code for Formaldehyde: InChI=1/CH2O/c1-2/h1H2
Source for SMILES and InChI: USEPA Distributed Structure-Searchable Toxicity (DSSTox) Database
Chemical Structure for Formaldehyde: 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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