Guanidinium phosphate (1:1)

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

An oral 90-day study (with specific focus on fertility parameters) and a pre-natal development study with substance analogue guanidine hydrochloride are available. The rationale to read across these data is attached in section 13. Taken all data together, there are no indications that the registered substance has effects on reproduction. In accordance with column 1 of REACH Annex IX, an extended one generation study (section 8.7.3) is required for >100T/year substances, if repeated dose studies indicate adverse effects on reproductive organs or tissues. As the available data do not indicate adverse effects, further testing is waived.

Effect on fertility: via oral route

Endpoint conclusion:

no study available

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Effects on developmental toxicity

Description of key information

A prenatal development study was performed with substance analogue guanidine hydrochloride according to OECD/EC guidelines and GLP principles. Based on this study, a no observed adverse effect level (NOAEL) for maternal toxicity of 150 mg/kg bw/day was found and a NOAEL of 350 mg/kg bw/day for developmental toxicity. This result is read across to guanidine phosphate (rationale attached in section 13).

Link to relevant study records

Reference

Endpoint:

developmental toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

The rationale to read across the data is attached in Section 13.

Reason / purpose for cross-reference:

read-across source

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

The clinical sign of slight to severe piloerection was noted transiently in several females of the HD group treated with 450 to 350 mg/kg bw/d whereas only one female of the control group showed piloerection on one single day. Regarding females of the HD group which received 350 mg/kg bw/d throughout the whole treatment period, one female showed slight piloerection on one single day and another female was noted on two single days with slight or moderate piloerection. Thus, these findings in females treated with 450 to 350 mg/kg bw/d can be considered of minor toxicological relevance and in the remaining females as incidental. Slight to severe salivation was noted transiently with a dose-dependent pattern in most females of the HD group (at 450 to 350 mg/kg bw/d as well as at solely 350 mg/kg bw/d) and few females of the MD group. Moving the bedding was observed transiently in all females of the HD group, 10 females of the MD group and one female of the LD group. As the symptoms of salivation and moving the bedding were noted mainly immediately after dose administration, these signs were considered to be indicative of discomfort due to a local reaction to the test item. None of the females showed signs of abortion prior to the scheduled sacrifice.

Mortality:

mortality observed, treatment-related

Description (incidence):

One female (no. 76) was euthanized in a moribund condition on gestation day 14 and another female of the HD group (no. 77) was found dead on gestation day 18. The animal of the HD group that was euthanized for welfare reasons on gestation day 14, showed marked loss of body weight, piloerection, moving the bedding and red nasal discharge. The animal of the HD group which was found dead on gestation day 18 lost body weight and was observed with slight to severe piloerection and a wasp waist. Females no. 76 and 77 were administered 450 mg/kg bw/d throughout their test participation.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

The mean body weight increased with the progress of the study in the control, the LD and the MD group. However, mean body weight of the HD group was slightly lower compared to the control group from gestation day 8 onwards but without achieving statistical significance. Body weight gain was also slightly lower in the HD group compared to the control group on various intervals within the study period and achieved statistical significance on day 5-8 (p<0.001). The same effect was seen with statistical significance (p<0.01) when considering only those females of the HD group which received a dose of 350 mg/kg bw/d for the whole treatment period. This effect on the body weight and body weight gain of the whole HD group as well as of the HD subgroup receiving a dose of solely 350 mg/kg bw/d was considered to be test item-related.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

In correlation to the body weight and body weight gain, food consumption in the HD group was noted to be slightly lower compared to the control group after the beginning of the treatment. Statistical significance was noted over the study period from day 0 to day 20 (p<0.001) as well as on several treatment intervals. Food consumption was comparably reduced when considering only those females of the HD group with a continuous dosage of 350 mg/kg bw/d. Likewise, statistical significance was noted over the study period from day 0 to day 20 (p<0.01) as well as on several treatment intervals. This effect on the food consumption of the whole HD group as well as of the HD subgroup receiving a dose of solely 350 mg/kg bw/d was considered to be test item-related.

Dose descriptor:

NOAEL

Effect level:

150 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

body weight and weight gain

food consumption and compound intake

mortality

Fetal body weight changes:

no effects observed

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): no effects observed

Reduction in number of live offspring:

no effects observed

Changes in sex ratio:

no effects observed

Changes in litter size and weights:

no effects observed

Changes in postnatal survival:

not examined

External malformations:

no effects observed

Description (incidence and severity):

There were no external abnormalities considered to be of toxicological relevance in any of the dose groups.

Skeletal malformations:

effects observed, non-treatment-related

Description (incidence and severity):

Craniofacial examination by a razor blade serial sectioning technique revealed few findings at frequencies generally comparable to or in some cases slightly higher or lower in frequency compared to the controls. Statistical analysis of the data revealed no significant effect in any of these findings as compared to the control group. Therefore, these findings are not to be considered to be treatment related and spontaneous in nature.
Skeletal examination of the Alizarin red stained foetuses revealed a range of abnormalities which were of a type or which occurred at an incidence comparably lower in treated groups when compared to the control group. Statistically significant decrease in litter incidence of incomplete ossification of frontal bone (B) in HD and of 4th sternebra in HD, 14th full rib (B) in LD and supernumerary rib cartilage (B) in LD was observed when compared to the control group. Lack of dose dependency and consistency in these findings indicated no relevance with treatment. There was no indication of a compound-related trend in the type and incidences of other abnormalities and they were therefore considered to be spontaneous in nature.

Visceral malformations:

effects observed, non-treatment-related

Description (incidence and severity):

A range of visceral findings observed in the dose groups were at frequencies generally comparable to or in some cases slightly higher or lower in frequency compared to the controls and litter incidences were statistically insignificant except for liver haematoma. Liver haematoma was noted with a statistically significantly higher litter incidence in the control group compared to the LD group without dose-dependency (C: 22%, LD: 0%, MD: 14%, HD: 10%). This was considered as incidental and not related to the treatment with the test item. As the remaining observed findings were either minor variations and/or due to a lack of dose dependency and consistency, no serious toxicological significance can be attributed to these findings and they were considered to be spontaneous in nature.

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
There were no test item-related effects of toxicological relevance noted on mean foetus weight, total number of foetuses, number of male and female foetuses, mean total litter weight and male and female litter weight.

There were no external abnormalities considered to be of toxicological relevance in any of the dose groups.

A range of visceral findings observed in the dose groups were at frequencies generally comparable to or in some cases slightly higher or lower in frequency compared to the controls and litter incidences were statistically insignificant except for liver haematoma. Liver haematoma was noted with a statistically significantly higher litter incidence in the control group compared to the LD group without dose-dependency (C: 22%, LD: 0%, MD: 14%, HD: 10%). This was considered as incidental and not related to the treatment with the test item. As the remaining observed findings were either minor variations and/or due to a lack of dose dependency and consistency, no serious toxicological significance can be attributed to these findings and they were considered to be spontaneous in nature.

Craniofacial examination by a razor blade serial sectioning technique revealed few findings at frequencies generally comparable to or in some cases slightly higher or lower in frequency compared to the controls. Statistical analysis of the data revealed no significant effect in any of these findings as compared to the control group. Therefore, these findings are not to be considered to be treatment related and spontaneous in nature.

Skeletal examination of the Alizarin red stained foetuses revealed a range of abnormalities which were of a type or which occurred at an incidence comparably lower in treated groups when compared to the control group. Statistically significant decrease in litter incidence of incomplete ossification of frontal bone (B) in HD and of 4th sternebra in HD, 14th full rib (B) in LD and supernumerary rib cartilage (B) in LD was observed when compared to the control group. Lack of dose dependency and consistency in these findings indicated no relevance with treatment. There was no indication of a compound-related trend in the type and incidences of other abnormalities and they were therefore considered to be spontaneous in nature.

Dose descriptor:

NOAEL

Effect level:

>= 350 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: See remarks

Abnormalities:

no effects observed

Developmental effects observed:

no

Prenatal parameters like group mean gravid uterus weight, adjusted maternal weight, number of corpora lutea, implantation sites, number of live and dead foetuses, number of early and late resorptions, number of male and female foetuses, sex ratio and pre- and post-implantation loss remained unaffected in the dose groups when compared to the control group. Pregnancy rates were comparable between the groups and within the normal range of variation for animals of this strain and age.

Conclusions:

In a prenatal development study performed with guanidine hydrochloride according to OECD/EC guidelines and GLP principles, a no observed adverse effect level (NOAEL) for maternal toxicity of 150 mg/kg bw/day was found and a NOAEL of 350 mg/kg bw/day for developmental toxicity. This result is read across to guanidine phosphate.

Executive summary:

In a developmental toxicity study according to OECD guideline 414 (adopted 22 January, 2001), guanidine hydrochloride was administered to female Wistar rats during gestation days 5 to 19.

The following doses were evaluated:

Control (C): 0 mg/kg body weight/day (21 females)

Low Dose: 50 mg/kg body weight/day (23 females)

Medium dose (MD) 150 mg/kg body weight/day (23 females)

High dose (HD): 350 mg/kg body weight/day (24 females)

Females were paired (ratio 1:2) for cohabitation in batches in order to regularise the number of animals for terminal sacrifice on a particular day.

At a dose level of 450 mg/kg bw/d mortality was observed in two animals and clinical symptoms occurred in more animals than in the control group resulting in a reduction of the highest dosage to 350 mg/kg bw/d. Animals treated with 450 to 350 mg/kg bw/d as well as animals receiving 350 mg/kg bw/d throughout the whole treatment period were noted with a statistically significantly reduced body weight gain and food consumption.

No effect on prenatal data, litter data, foetal external, visceral, skeletal and craniofacial parameters were observed up to the highest dose level.

Maternal toxicity: NOAEL: 150 mg/kg bw/day

Based on mortality at 450 mg/kg bw/day; statistically significantly reduced body weight gain and food consumption (450 and 350 mg/kg bw/day)

Developmental toxicity: NOAEL: 350 mg/kg bw/day

No effects on prenatal data, litter data, foetal external, visceral, skeletal and craniofacial parameters were observed up to the highest dose level

This result is read across to guanidine phosphate.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

350 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

Klimisch 1 study.

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

In a developmental toxicity study according to OECD/EC guidelines and GLP principles, guanidine hydrochloride was administered to female Wistar rats during gestation days 5 to 19.

Doses of 0, 50, 150 and 450 mg/kg body weight/day were evaluted. Females were paired (ratio 1:2) for cohabitation in batches in order to regularise the number of animals for terminal sacrifice on a particular day. At a dose level of 450 mg/kg bw/d mortality was observed in two animals and clinical symptoms occurred in more animals than in the control group resulting in a reduction of the highest dosage to 350 mg/kg bw/d. Animals treated with 450 to 350 mg/kg bw/d as well as animals receiving 350 mg/kg bw/d throughout the whole treatment period had a statistically significantly reduced body weight gain and food consumption. No effect on prenatal data, litter data, foetal external, visceral, skeletal and craniofacial parameters were observed up to and including the highest dose level.

Based on mortality at 450 mg/kg bw/day and statistically significantly reduced body weight gain and food consumption at 450 (350) mg/kg bw/day), the maternal NOAEL was established to be 150 mg/kg bw/day. As no effects were seen on prenatal data, litter data, foetal external, visceral, skeletal and craniofacial parameters up to and including the highest dose level, the developmental NOAEL was established to be equal to or to exceed 350 mg/kg bw/day. This result is read across to guanidine phosphate (rationale attached in section 13).

Justification for classification or non-classification

Based on the available data, guanidinium phosphate (1:1) is not classified for reproduction/ developmental toxicity according to CLP Regulation (EC) No. 1272/2008.