Table 11.
Study 6 – Two-year feeding study of glyphosate in rats (Arysta Life Sciences 1997b).
| Study owner: | Arysta Life Sciences (1997b) | |||||
| Reliability/Justification: | 1 Study performed according to GLP and OECD guideline requirements, with no deviations. | |||||
| Substance: | Glyphosate (94.6–97.6% pure) | |||||
| Species/Strain: | Rat/Sprague-Dawley, groups of 50 ♂ and 50 ♀; satellite groups of 30 ♂ and 30 ♀for interim investigations | |||||
| Administration route: | Diet | |||||
| Concentration: | 0, 3000, 10 000, 30 000 ppm diet (♂ about 0, 104, 354, 1127 mg/kg bw/day; ♀ about 0, 115, 393, 1247 mg/kg bw/day) | |||||
| Duration: | 2 years | |||||
| Findings: | 3000 ppm diet: NOAEL (♂+♀) 10 000 ppm diet: cecum weight↑, distension of cecum, loose stool, follicular hyperkeratosis and/or folliculitis/follicular abscess of the skin, body weight ↓ |
|||||
| Select neoplasms: | Pituitary adenoma, skin keratoacanthoma (males), mammary gland fibroadenoma (females) | |||||
| Tumor | Dose (mg/kg bw/day) | |||||
| Males | 0 | 104 | 354 | 1127 | ||
| Findings for dead and moribund sacrificed animals (Table 25–10) | ||||||
| Pituitary anterior adenoma – B | 22/32 (69%) | 21/30 (70%) | *14/32 (44%) | 18/21 (86%) | ||
| Skin keratoacanthoma – B | 2/32 (6%) | 1/30 (3%) | 0/32 | 1/21 (5%) | ||
| Findings for animals sacrificed at termination (after 104 weeks, Table 25–8) | ||||||
| Lung adenoma – B | 0/18 | 2/20 (10%) | 1/18 (6%) | 3/29 (10%) | ||
| Pituitary anterior adenoma – B | 13/18 (72%) | 14/20 (70%) | 13/18 (72%) | 21/29 (72%) | ||
| Pituitary adenoma in intermediate part – B | 0/18 | 1/20 (5%) | 0/18 | 0/29 (0%) | ||
| Skin keratoacanthoma – B | 1/18 (6%) | 2/20 (10%) | 0/18 | 6/29 (21%) | ||
| Tumor | Dose (mg/kg bw/day) | |||||
| Females | 0 | 115 | 393 | 1247 | ||
| Findings for dead and moribund sacrificed animals | ||||||
| Pituitary anterior adenoma – B | 34/35 (97%) | 29/31 (94%) | 28/33 (82%) | 31/36 (86%) | ||
| Thyroid follicular adenoma – B | 0/35 | 2/31 (6%) | 0/32 | 0/36 | ||
| Mammary gland fibroadenoma – B | 13/35 (37%) | 14/31 (45%) | 12/34 (35%) | 20/36 (56%) | ||
| Findings for animals sacrificed at termination | ||||||
| Pituitary anterior adenoma – B | 12/15 (80%) | 19/19 (100%) | 12/16 (75%) | 13/14 (93%) | ||
| Mammary gland fibroadenoma – B | 10/15 (67%) | 13/19 (68%) | 12/16 (75%) | 10/14 (71%) | ||
B benign, M malignant
*Statistically lower than controls (p < 0.05).