N-(carboxymethyl)-N-(phosphonomethyl)glycine

Toxicity to reproduction

Administrative data

Endpoint:

one-generation reproductive toxicity

Remarks:

based on test type (migrated information)

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

From Aug. 23, 1984 to Feb. 21, 1986

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted equivalent or similar to OECD Guideline 415.

Justification for data waiving:

other:

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1986

Report date:

1986

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 415 [One-Generation Reproduction Toxicity Study (before 9 October 2017)]

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

N-(carboxymethyl)-N-(phosphonomethyl)glycine

EC Number:

227-824-5

EC Name:

N-(carboxymethyl)-N-(phosphonomethyl)glycine

Cas Number:

5994-61-6

Molecular formula:

C5H10NO7P

IUPAC Name:

2-[(carboxymethyl)(phosphonomethyl)amino]acetic acid

Details on test material:

- Name of test material (as cited in study report): Glyphosate intermediate
- Physical state: Fine white powder
- Lot/batch No.: LUIG 03014

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, Inc., Portage, Michigan
- Age during mating: 17 wk
- Weight at study initiation: Males: 301-441 g; females: 192-222 g
- Housing: During the exposure and non-exposure period, animals were housed individually in stainless steel cages except during mating when a treated female was housed with one untreated male, and two untreated females were housed with one treated male nightly, and during parturition and lactation when the females were housed in plastic cages with wood chip nesting material.
- Diet: Purinae Certified Rodent Chow ® # 5002, ad libitum
- Water: tap water:
- Acclimation period: 10 d

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure (if applicable):

whole body

Vehicle:

unchanged (no vehicle)

Details on exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: 16 m3 glass and stainless steel exposure chambers
- Source and rate of air: Chamber ventilation air was supplied from an HVAC system
- Method of conditioning air: The air was filtered to remove particulates, and temperature and humidity were controlled.
- System of generating particulates/aerosols: Dust aerosol atmosphere of test material generated with an auger dust feed.
- Air flow rate: 2000 and 4000 L/minute
- Method of particle size determination: The particle size distribution of the test material aerosol was determined once every other wk for each exposure group with an Andersen® 8-stage cascade impactor


TEST ATMOSPHERE
- Brief description of monitoring of exposure concentration: Nominal exposure concentrations were determined weekly. Actual exposure concentrations were determined daily using pseudo average gravimetric techniques. In addition, real-time monitoring, using a light-scattering aerosol monitor, was performed hourly to assist in monitoring the operation of the generation system.
- Test material distribution in chamber atmosphere: Distribution of the test material within the chambers was entirely adequate for the purposes
of the study

Details on mating procedure:

- M/F ratio per cage: A treated female was housed with one untreated male, and two untreated females were housed with one treated male nightly
- Length of cohabitation: 10 d
- Proof of pregnancy: Copulatory plug or by vaginal inspection for sperm of pregnancy, referred to as Day 0 of gestation
- After 10 d of unsuccessful pairing replacement of first male by another male with proven fertility.
- Further matings after two unsuccessful attempts: Any female that failed to show evidence of copulation after the initial 10 d period was housed for an additional 5 d with a second male (sperm positive during the initial 10 days) selected from the same group.
- After successful mating each pregnant female was caged (how): Individual plastic cage with wood chip bedding

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Once each week, amount of test material collected on the glass fiber filters was determined analytically with high pressure liquid chromatography for the determination of exposure concentration. Distribution of the test material within the chambers was entirely adequate for the purposes of the study.
97% of the aerosol was less than 9 microns, in terms of aerodynamic diameter. Thus, an equivalent aerodynamic diameter of about 3 mcm with a GSD of 1.6 would describe an aerosol where essentially all (99%) of the aerosol was respirable (<10 mcm).

Duration of treatment / exposure:

10 weeks

Frequency of treatment:

Exposure frequency in males: 6 h/d, 5 d/wk; Exposure frequency in females: 6 h/d, 5 d/wk until evidence of copulation observed after which they were exposed 7d/wk until sacrificed at the termination of weaning, except for gestation Day 20 through lactation Day 3, during which they were not exposed. Treatment was resumed on lactation Day 4 and continued through lactation Day 21

Details on study schedule:

- Age at mating of the mated animals in the study: 17 weeks

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
0, 1.1, 10 or 105 mg/m3
Basis:
nominal conc.

Doses / concentrations 2

Remarks:

Doses / Concentrations:
0, 0.86, 9.6 and 102 mg/m3
Basis:
analytical conc.

No. of animals per sex per dose:

15 exposed and 25 non-exposed males; 25 exposed and 30 non-exposed females.

Control animals:

yes, concurrent no treatment

Details on study design:

- Dose selection rationale: Exposure levels were selected on the basis of pilot study. 5 males and 5 females albino rats (Charles River CD) were exposed for 6 h/d for 5 d to dust aerosol atmospheres of test material at a concentration of 0, 1.0, 10 or 100 mg/m3. No rats died and no clinical signs were seen in any animal. The high exposure level of 100 mg/m3 was considered acceptable for 13 wk inhalation study since it represented l0 times the ACGIH TLV for a nuisance dust (10 mg/m3 , total dust), and produced no significant toxicity in the pilot study.

Positive control:

Not reported

Examinations

Parental animals: Observations and examinations:

MORTALITY: Yes
- Time schedule: Twice daily

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Twice daily

BODY WEIGHT: Yes
- Time schedule for examinations: Untreated male rats were weighed weekly. All female (treated and untreated) rats were weighed weekly until evidence of copulation was observed. Untreated females were also weighed on gestation Days 0, 7, and 13. Treated females were allowed to deliver, and were weighed on gestation Days 0, 7, 13, and 20 and on lactation Days 0, 7, 14, and 21.


OTHER: Throughout lactation, the dams were observed daily for behavioral abnormalities in nesting and nursing

Oestrous cyclicity (parental animals):

The treated females had undergone daily vaginal examinations to establish estrous cycles beginning 11 d prior to mating.

Sperm parameters (parental animals):

Parameters examined in P male parental generations: Sperm counts and motility and sperm morphology were evaluated

Litter observations:

STANDARDISATION OF LITTERS
- Performed on lactation Day 4
- Litter size was reduced to 10 pups, with equal sex distribution where possible. The culled pups were examined externally and discarded.


PARAMETERS EXAMINED
The following parameters were examined in F1 offspring: On lactation Day 0, litters were examined for litter size, stillbirths, live births and any gross anomalies. Pups were weighed individually on lactation Days 0, 4, 7, 14 and 21. The number of pups/sex was recorded on lactation Days 4 and 21.

GROSS EXAMINATION OF DEAD PUPS: Yes, any intact dead pups were necropsied and examined for anomalies. Pups that died before culling on Day 4 of lactation were eviscerated. .

Postmortem examinations (parental animals):

SACRIFICE
- Male animals: The untreated males were sacrificed and discarded after completion of parturition of the corresponding treated females. Following completion of mating, the treated males were returned to, and continued on, the regular 13 wk inhalation toxicity schedule until sacrifice.
- Maternal animals: All females, where no evidence of mating was observed and which did not deliver, were sacrificed 25 d after separation from the male animals. On gestation Day 13, all of the untreated females were sacrificed by carbon dioxide inhalation for uterine examination. On lactation Day 21, all dams were sacrificed.


GROSS NECROPSY
- Gross necropsy: In females sacrificed on gestation Day 13, the number and location of viable and nonviable embryos, early resorptions, the total number of implantions and corpora lutea were recorded. Each implantation site, including resorptions, was numbered from the left uterine horn to the right uterine horn. The abdominal and thoracic cavities were examined for grossly evident morphological changes and the carcasses discarded.
On lactation Day 21, all dams were sacrificed, a gross necropsy was performed and the number of uterine implantation sites was recorded.
On 25th day after separation from the male, gross necropsy was performed on all females where no evidence of mating was observed and which did not deliver
.

Postmortem examinations (offspring):

SACRIFICE
- The F1 offspring: All externally normal pups were sacrificed and discarded. Any pup with an external abnormality at weaning was sacrificed and necropsied.

Statistics:

- Mean postimplantation loss was compared by the Mann Whitney U-test.
- The mean numbers of corpora lutea, total implantations and viable embryos were compared by analysis of variance (one-way classification}, Bartlett's test for homogeneity of variance and the appropriate t-test using Dunnett's multiple comparison tables to judge significance of differences.
- The male and female fertility indices were compared using the Chi-square test criterion with Yates' correction for 2 x 2 contingency tables.
- Pup survival indices were compared by the Mann-Whitney U-test.
- Mean number of live pups per litter at birth and mean pup body weights were compared by analysis of variance (one-way classification), Bartlett's test for homogeneity of variances and the appropriate t-test using Dunnett's multiple comparison tables to judge significance of differences.

Reproductive indices:

- Pregnancy index: Calculated by dividing the number of gravid females by the number of females paired with males (number of females in each group). Multiplying by 100 yields the percent of gravid females in each group.
- Male fertility index: Derived similarly by determining the number of males in each group that were responsible for a pregnancy and dividing by the
number of males paired with females (number of males in each group).

Offspring viability indices:

Not reported

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

effects observed, treatment-related

Body weight and weight changes:

effects observed, treatment-related

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Organ weight findings including organ / body weight ratios:

not examined

Histopathological findings: non-neoplastic:

not examined

Other effects:

not examined

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

no effects observed

Reproductive function: sperm measures:

no effects observed

Reproductive performance:

effects observed, treatment-related

Details on results (P0)

CLINICAL SIGNS AND MORTALITY (PARENTAL ANIMALS): Five high exposure level females died during the study. Treatment-related findings in these animals included thin appearance and labored breathing and unkempt haircoat. females were somewhat more sensitive to test material than males.


BODY WEIGHT AND FOOD CONSUMPTION (PARENTAL ANIMALS): Body weights were reduced in high exposure level females from exposure Week 2 through 10 and throughout gestation and most of the lactation period. At the beginning of gestation, the mean body weight for this group was 9 % less than controls. By lactation Day 14 they weighed 18 % less than controls. The body weight of all other treated female groups and all untreated animals were comparable to controls throughout the study. The body weight inhibitions sustained by high exposure level females were confirmed further by a notable reduction in body weight gain during the overall gestation period (Days 0 to 20). The weekly and maternal body weights of the treated females in low and mid dose levels were not appreciably different from the control.


REPRODUCTIVE FUNCTION: ESTROUS CYCLE (PARENTAL ANIMALS): No abnormalities attributable to the test material were noted in the estrous cycling of the treated females in any group. Short diestrous and long post-estrous were observed exclusively in the treated groups, but low incidence negated any biological significance.


REPRODUCTIVE FUNCTION: SPERM MEASURES (PARENTAL ANIMALS): Mean sperm concentration, and epididymal and testicular weights of the
treated groups were comparable to those of the control. Examination of sperm morphology of the treated groups revealed no findings which can be considered exposure related. Percent abnormal sperm ranged from 0% to 7% in the treated groups and from 3% to 15% in the control.


REPRODUCTIVE PERFORMANCE (PARENTAL ANIMALS): No adverse effect of treatment on female reproductive outcome was noted for untreated females mated to exposed males. The number of corpora lutea, implantations, post-implantation loss, and viable embryos were similar for all treated and control groups. The mean copulatory interval for these matings was increased in a dose related manner at the mid and high exposure levels as compared to both concurrent and historical control values. Male fertility index was also reduced in dose-related fashion for these same groups. Thus, an effect of treatment on male copulatory behavior was observed. The fertility indices of the treated females of all groups were not appreciably different from that of the control group.
No exposure-related effects were apparent on estrous cycling, copulatory interval, fertility indices, nidation, parturition, or nesting and nursing behavior of exposed females mated with unexposed males


NECROPSY FINDINGS (PARENTAL ANIMALS): Gastrointestinal abnormalities observed in several females which died during study. Two had no contents in their stomach which was suggestive of inappetence prior to death. Although no specific cause of death could be determined for any female that died prior to the study termination, the premature deaths and the antemortem and necropsy observations were considered treatment-induced. Lung lesions were observed in four females of high dose group that survived to scheduled sacrifice. No antemortem or necropsy findings considered related to treatment were observed in the treated females in either low and mid dose groups.

Effect levels (P0)

Dose descriptor:

NOEL

Effect level:

9.6 mg/m³ air (analytical)

Sex:

male/female

Basis for effect level:

other: Reproductive impairment

Results: F1 generation

General toxicity (F1)

Clinical signs:

not examined

Mortality / viability:

mortality observed, treatment-related

Body weight and weight changes:

effects observed, treatment-related

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

not examined

Histopathological findings:

not examined

Details on results (F1)

VIABILITY (OFFSPRING): The number of viable pups per dam and pup survivability on lactation Days 0 and 4 were reduced as compared to controls at the high exposure level


BODY WEIGHT (OFFSPRING): Reduced body weights observed in the high exposure level group on lactation Days 4 through 21. The body weights were significantly less than the control values on Days 7 and 14, and for females on Day 21.


NECROPSY FINDINGS (OFFSPRING): Abnormal observations noted in the surviving pups included inactivity, paleness and/or breathing difficulties in three pups of control group, one pup in mid dose, and two pups in high dose. These and several inconsequential findings were incidental in occurrence and therefore not considered meaningful. Skeletal examinations of pups dying before Day 4 did not disclose any findings that could be deemed exposure-related


OTHER FINDINGS (OFFSPRING): All litter parameter values for the low and mid exposure level groups were comparable to control group values from birth through lactation. Observation of pups throughout lactation failed to disclose any abnormalities considered to be exposure-related.

Overall reproductive toxicity

Reproductive effects observed:

not specified

Any other information on results incl. tables

None

Applicant's summary and conclusion

Conclusions:

Exposure of male and female rats to the test material aerosols at 0, 1.1, 10, and 105 mg/m3 of air resulted in increased mortality, decreased body weight, decreased number of viable pups/dam, pup weight, and pup survivability, and altered male mating behavior at the high exposure level. Under the conditions of the test, the no observed effect level (NOEL) for reproductive impairment was found to be 9.6 mg/m3.

Executive summary:

A study was conducted to evaluate one generation reproductive toxicity of test material in albino rats.

 

Animals were exposed to test material (as a dust aerosol) at target exposure concentrations of 0, 1.0, 10, or 100 mg/m3 of air (mean analytical concentrations 0.86, 9.6, and 102 mg/m3 of air) for10 wk at 6 h/d, 5 d/wk for males and 6 h/d, 5 d/wk in females until evidence of copulation observed. Thereafter they were exposed at 7d/wk until sacrificed at the termination of weaning, except for gestation Day 20 through lactation Day 3, when they were not exposed. At each exposure level there were15 exposed males, 25-non-exposed males, 25 exposed females, and 30 non-exposed females. Matings were between treated males and untreated females, treated females and untreated males, and untreated males and untreated females.

 

Increased mortality, decreased body weight, decreased number of viable pups/dam, pup weight, and pup survivability, and altered male mating behavior observed in high exposure levels animals. No exposure-related effects were apparent on estrous cycling, copulatory interval, fertility indices, nidation, parturition, or nesting and nursing behavior of exposed females mated with unexposed males. No exposure-related abnormalities in sperm count, motility, or morphology was observed in males.

 

Under the conditions of the test, the no observed effect level (NOEL) for reproductive impairment was found to be 9.6 mg/m3.