Supernatant from the crystallisation of L-threonine from the broth filtrate from the fermentative production of L-threonine

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Effect on fertility: via oral route

Endpoint conclusion:

no study available

Quality of whole database:

For L-threonine mother liquor itself there are no studies available. Therefore, data for the read-across substance Biofert Plusz are taken into further consideration.

Biofert Plusz was tested in subacute and subchronic studies, which gave no indication for adverse effects (e.g. on reproductive organs) leading to C&L. Therefore, there is no need for further testing on reproductive toxicity (e.g. 1- or 2-generation toxicity). In addition further testing on vertebrates is not considered to be required for animal welfare reasons.

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Quality of whole database:

For L-threonine mother liquor itself there are no studies available. Therefore, data for the read-across substance Biofert Plusz are taken into further consideration.

Biofert Plusz was tested in subacute and subchronic studies, which gave no indication for adverse effects (e.g. on reproductive organs) leading to C&L. Therefore, there is no need for further testing on reproductive toxicity (e.g. 1- or 2-generation toxicity). In addition further testing on vertebrates is not considered to be required for animal welfare reasons.

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Quality of whole database:

For L-threonine mother liquor itself there are no studies available. Therefore, data for the read-across substance Biofert Plusz are taken into further consideration.

Biofert Plusz was tested in subacute and subchronic studies, which gave no indication for adverse effects (e.g. on reproductive organs) leading to C&L. Therefore, there is no need for further testing on reproductive toxicity (e.g. 1- or 2-generation toxicity). In addition further testing on vertebrates is not considered to be required for animal welfare reasons.

Effects on developmental toxicity

Description of key information

For L-threonine mother liquor itself there are no studies available. Therefore, data for the read-across substance Biofert Plusz are taken into further consideration.
In Wistar rats no maternal and developmental toxicity was detected in a GLP gavage study according to OECD Guideline 414 even at the high dose level of 1000 mg/kg bw/day (related to dry weight) which corresponds to the limit dose recommended in the Guideline.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Species:

rat

Additional information

In a GLP study according to OECD guideline 414 (adopted 2001) groups of 22 pregnant Wistar rats were gavaged day 6 -20 post coitum (pc) with 0, 100, 300, or 1000 mg/kg bw/day (related to dry weight of the liquid test item; vehicle water; application volume 10 mL/kg bw); the study was terminated day 21 pc. Stability and homogeneity of the test substance has been shown. Non-pregnant rats were found only 2/22 in control and 1/22 in the low dose group. No clinical signs were detected. The mean food consumption was significantly reduced from day 6 to 9 post coitum in the high dose group, however, this transient reduction was considered to be test item-related but not adverse (no effect on body weight; reduction less than 10%). The mean body weight and body weight gain was similar in all groups and also no effects on corrected body weight gain was observed. No effects were seen on post-implantation loss and mean number of fetuses. Necropsy revealed no test item-related findings. Furthermore, no treatment-related effects were detected on the fetal sex ratio, fetal body weights, implantations, resorptions, dead fetuses, or abnormal fetuses. No test item related increase in external, visceral, or skeletal malformations or variations were found. Significantly higher incidence of incompletely ossified sternebra 5 was noted at the high dose level. Since this incidence was in the range of the historical control data it was considered to reflect the range of natural biological variability. In conclusion, the NOAEL for maternal and developmental toxicity is 1000 mg/kg bw/day (dry mass).