Registration Dossier

Administrative data

Description of key information

Acute oral toxicity: 300 mg/kg bw < LD50 ≤ 2000 mg/kg bw (LD50 cut-off mg/kg bw: 500 mg/kg bw) (OECD 423, GLP compliant)
Acute inhalation toxicity: data waiving
Acute dermal toxicity: LD50 > 2000 mg/kg bw (OECD 402, GLP compliant)

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion
Dose descriptor:
LD50
Value:
500 mg/kg bw

Additional information

Acute oral toxicity

One reliable animal study described in Vaeth (2004) (OECD 423; GLP compliant) is considered to be reliable without restrictions. The LD50 was determined to be between 300 and 2000 mg/kg bw ( LD50 cut-off mg/kg bw: 500 mg/kg bw).

Acute inhalation toxicity study

According to regulation (EC) 1907/2009 Annex VIII column 2 no study on acute toxicity via inhalation should be conducted due to the corrosive property of the substance (C&L as corrosive to skin).

Nevertheless, the potential for dust inhalation is considered moderate, since during measurements of the particle size distribution, clear indications of a high tendency for agglomeration of particles were observed, necessitating dry sieving of the test material prior to testing. As a consequence, approx. 26% of the material was > 250 µm.

Furthermore, the material was subjected to a test to determine the potential of the dust to be airborne (modified Heubach procedure (DIN 55992-1:2006)), yielding an MMAD of 26.5 µm with a GSD of 1.7. On the basis of results of this dustiness test (modified Heubach method), a MPPD modelling was performed and shows that only minimal amounts (~0.3%) of the substance are able to penetrate to the deep lung tissue, whereas the overwhelming bulk (99.7%) of inhaled material is cleared rapidly to the GI tract (by swallowing), where oral bioavailability will determine its uptake.

Acute dermal toxicity study

One reliable animal study described in Haferkorn (2006) (OECD 402; GLP compliant) is considered to be reliable without restrictions. The LD50 was determined to be greater than 2000 mg/kg bw.

Justification for classification or non-classification

Acute toxicity

According to regulation (EC) 1272/2008 and subsequent amendments the substance is classified as Category 4.

Specific target organ toxicant (STOT) - single exposure: oral

The classification criteria according to regulation (EC) 1272/2008 as specific target organ toxicant (STOT) – single exposure, oral are not met since no reversible or irreversible adverse health effects were observed immediately or delayed after exposure and no effects were observed at the guidance value, oral for a Category 1 classification (C≤ 300 mg/kg bw) and at the guidance value, oral for a Category 2 classification (2000 mg/kg bw≥C > 300 mg/kg bw) in addition to these effects which were responsible for the death of the animals. No classification required.

Specific target organ toxicant (STOT) - single exposure: dermal

The classification criteria according to regulation (EC) 1272/2008 as specific target organ toxicant (STOT) – single exposure, dermal are not met since no reversible or irreversible adverse health effects were observed immediately or delayed after exposure and no effects were observed at the guidance value, dermal for a Category 1 classification (C≤ 1000 mg/kg bw) and at the guidance value, dermal for a Category 2 classification (2000 mg/kg bwC > 1000 mg/kg bw) in addition to these effects which were responsible for the death of the animals. No classification required.

Specific target organ toxicant (STOT) - single exposure: inhalation

No study on acute inhalation toxicity was preformed due to the corrosive property of the substance.

However, for substances and mixtures classified as skin corrosive, the additional labelling EUH071: Corrosive to the respiratory tract should be used in case no acute inhalation test data are available or the substance may be inhaled.

Nevertheless, MPPD modelling shows that only minimal amounts (~0.3%) of the substance are able to penetrate to the deep lung tissue, whereas the overwhelming bulk (99.7%) of inhaled material is cleared rapidly to the GI tract (by swallowing), where oral bioavailability will determine its uptake.