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

Endpoint summary

Description of key information

In male and female Hsd/Win:WU rats the oral LD50 for L-threonine mother liquor is > 2150 mg/kg bw.
For the read-across substance Biofert Plusz a dermal LD50 of > 2000 mg/kg bw (related to dry mass) was determined in male and female Wistar rats.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

2 150 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Quality of whole database:

In accordance with Section 8.5 in column 2 of REACH Annex VIII, no testing of the acute inhalation toxicity is required since valid data on acute oral and dermal toxicity are available.

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Additional information

The acute oral toxicity L-threonine mother liquor was studied in a test according to OECD Guideline 401 with male and female Hsd/Win:WU rats. One group of 5 m and 5 f was treated with 4.64 mL/kg bw by oral gavage corresponding to 2150 mg/kg bw. All animals were examined for clinical signs, mortality and body weights during the 14 d postexposure period. All animals were necropsied and examined macroscopically at termination. As clinical signs sunken sides and red incrustrated noses were observed. No macroscopic findings were recorded at necropsy. The LD50 is > 2150 mg/kg bw.

The acute dermal toxicity of the read-across substance Biofert Plusz was studied in male and female Wistar rats using a Limit test according to OECD Guideline 402. Five male and 5 female rats received dermal application to the clipped skin of 7.12 mL/kg bw undiluted Biofert Plusz corresponding to 2000 mg/kg bw (related to dry mass). The semi-occlusive dressing was removed after 24 h of exposure and the skin was washed. All animals were examined for clinical signs within the first 30 min and approximately 1, 2, 3 and 5 h after treatment and once daily during test days 2 -15. Body weights were recorded on day 1 (prior to administration) and on days 8 and 15. All animals were necropsied and examined macroscopically at termination. No clinical signs were observed during the course of the study. The body weight of the animals was within the range commonly recorded for this strain and age. No macroscopic findings were recorded at necropsy. The LD50 is > 2000 mg/kg bw (related to dry mass).

In accordance with Section 8.5 in column 2 of REACH Annex VIII, no testing of the acute inhalation toxicity is required since valid data on acute oral and dermal toxicity are available.