US EPA

65016 

Journal Article 

Safety evaluation of toothpaste containing chloroform: III long-term study in beagle dogs 

Heywood, R; Sortwell, RJ; Noel, PRB; Street, AE; Prentice, DE; Roe, FJC; Wadsworth, PF; Worden, AN 

1979 

Yes 

Journal of Environmental Pathology, Toxicology and Oncology
ISSN: 0731-8898
EISSN: 2162-6537 

2 

3 

835-851 

English 

422938 

Beagle dogs were given chloroform in a toothpaste base orally in
gelatin capsules on 6 d/wk for 7 1/2 yr, followed by a 20-24 wk
recovery period. Groups of 16 males and females received 0.5
ml/kg/d of the vehicle (toothpaste without chloroform) and 8
dogs of each sex remained untreated. Treated groups comprised 8
dogs of each sex, receiving doses equivalent to 15 and 30 mg
CHCI3/kg/d in the toothpaste vehicle; another group of the same
size received an alternative non-chloroform toothpaste (0.5
ml/kg/d). Eleven of the 96 dogs died during the study, only two of
these being in the CH03-treated groups. The only significant
toxic response during treatment was a moderate rise in serum
enzyme levels (e.g. SGPT), reaching a peak in the sixth year of
the study and probably corresponding to minimal liver damage.
Few palpable growths were noted while the dogs were alive.
"Fatty cysts" were seen in the liver of several dogs at post
mortem possibly associated with the chloroform treatment but the
distribution of a nodular change in the liver was not obviously
dose related. A small number of macroscopic and microscopic
neoplasms were seen; one dog in each chloroform-treated group
had a malignant tumour but there were no tumours in the liver or
kidney of any dog. Overall, exposure to chloroform in a toothpaste
base was not associated with any effect on the incidence of
any kind of neoplasm.
From this and related studies in mice and rats, it is concluded
that repeated exposure to chloroform (3.5 percent) in toothpaste
is unlikely to result in any hazard to human health.