Potassium trifluorozincate

Endpoint summary

Description of key information

A LD50 range between 200-2000 mg KZnF3/kg bw was observed in the acute oral toxicity study, a LC50 greater than 75 mg KZnF3/m3 was observed in the inhalation toxicity study, and a LD50 >2000 mg KZnF3/kg bw was observed in the acute dermal toxicity study.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Quality of whole database:

GLP compliant guideline study, klimisch 1

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LC50

Value:

75 mg/m³ air

Quality of whole database:

GLP compliant guideline study, klimisch 1

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

GLP compliant guideline study, klimisch 1

Additional information

Oral:

In a GLP-compliant OECD Guideline 423 study with Wistar rats, the oral toxicity of Nocolok Zn Flux was determined. Nocolok Zn Flux was administered once by oral gavage to three Wistar rats per sex per dose. Female rats were exposed to 200 and 2000 mg/kg bw and male rats to 200 mg/kg bw. All animals were subjected to daily observations and weekly determination of body weight. Macroscopic examination was performed on the day of death or after terminal sacrifice (day 15). Three females given 2000 mg/kg body weight were found dead. The decedents were found within 2 hours post-treatment. No further mortality occurred. No clinical signs were noted. The mean body weight gain shown by the animals over the study period was considered to be normal. No abnormalities were found at macroscopic post mortem examination of the animals. The oral LD50 value of Nocolok Zn Flux in Wistar Rats was established to be within the range of 200-2000 mg/kg body weight.

Inhalation:

In a GLP-compliant 7-day range finding study groups of 3 animals/sex were exposed to target concentrations of 0 (control), 2, 10 or 50 mg/m3 Nocolok Zn Flux. In the weekend following the first 6-hour exposure to 50 mg/m3, 2/6 of the animals of the high concentration group were found dead. Histopathological examination revealed hyperaemia, haemorrhages and interstitial pneumonia in the lungs, and olfactory epithelial degeneration and rhinitis in the nasal tissues of these animals. After a reduced 3-hour exposure period to 50 mg/m3 Nocolok Zn Flux on the second exposure day, the target concentration for the high concentration group was reduced to 25 mg/m3 for the remainder of the study. The surviving animals of the high concentration group showed decreased body weight gain and food consumption; increased lung weights and spongy lungs at necropsy; and histopathological examination revealed interstitial pneumonia and degeneration of olfactory epithelium in the nasal cavity. At the mid concentration level, increased lung weights were observed in females, all animals showed olfactory epithelial degeneration (though less severe than at the high concentration), and one female also showed focal alveolitis. The focal alveolitis was also found in the lungs of two animals of the low concentration group, exposed to a target concentration of 2 mg/m3 Nocolok Zn Flux. A single 6-hour exposure to a target concentration of 50 mg/m3 Nocolok Zn Flux resulted in mortality in 2/6 animals. The LC33 is therefore 50 mg/m3. If Haber's rule is applied, the 4 -hour LC33 would be 75 mg/m3. The LC50 will be above this concentration.

Dermal:

In a GLP compliant dermal toxicity study, performed according to OECD guideline 402, Wistar rats (5/sex) were treated with potassium trifluorozincate (2000 mg/kg bw) by dermal application. The test substance was administered on the clipped skin and covered with an occlusive dressing for 24 hours. After 24 hours the dressing was removed and the skin was cleaned with tap water. A 14-day observation period followed. No deaths occurred during the study, the body weight of the animals was within the range commonly recorded for this strain and age, and no macroscopic abnormalities were observed. Hunched posture was noted in one male and one female and piloerection was noted in all males. Chromodacryorrhoea on the snout was noted among the animals and one male showed diarrhoea. All animals recovered from these signs by Day 2.Based on the observations, the LD50 of potassium trifluorozincate is greater than 2000 mg/kg bw.

Justification for selection of acute toxicity – oral endpoint
GLP-compliant guideline study.

Justification for selection of acute toxicity – inhalation endpoint
GLP-compliant guideline study.

Justification for selection of acute toxicity – dermal endpoint
GLP-compliant guideline study.

Justification for classification or non-classification

The oral LD50 is determined to be in the range of 200-2000 mg/kg bw in the acute oral toxicity study. The cut-off for the EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008 lies at 300 mg/kg bw. Since no mortality was observed at 200 mg/kg bw it is expected that 50% mortality will not be observed below 300 mg/kg bw. Therefore, the test substance needs to be classified as Category 4: H302. According to Directive 67/548/EEC, the test substance needs to be classified as Xn:R22.

Based on the observed LC50 greater than 75 mg/m3 in the range-finding study and assuming that >50% of the animals would not survive the next classification cut-off of 500 mg/m3, the test substance needs to be classified as Category 2: H330 according to the EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008 and as T+:R26 according to Directive 67/548/EEC.

Based on the observed dermal LD50 greater than 2000 mg/kg bw classification for acute dermal toxicity according to the EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008 and according to Directive 67/548/EEC is not needed.