Trizinc bis(orthophosphate)

Endpoint summary

Description of key information

Acute oral toxicity: key study carried out according to OECD guideline no 401 indicating for trizinc bis(orthophosphate) LD50 > 5000 mg/kg bw
Acute inhalation toxicity: key study carried out according to OECD guideline no 403 indicating for zinc oxide LC50 > 5.7 mg/L/4hrs (read-across to trizinc bis(orthophosphate)

 

 

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

Used in EU risk assessment for zinc phosphate

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

not specified

Details on test animals or test system and environmental conditions:

No data

Route of administration:

oral: unspecified

Vehicle:

not specified

Details on oral exposure:

No data

Doses:

Not specified

No. of animals per sex per dose:

No data

Control animals:

not specified

Details on study design:

No data

Statistics:

No data

Preliminary study:

Not applicable

Sex:

not specified

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Mortality:

no mortality

Clinical signs:

other: no effects

Gross pathology:

no effects

Other findings:

None

None

Interpretation of results:

GHS criteria not met

Conclusions:

LD50 oral rat is >5000 mg zinc phosphate/kg bw

Executive summary:

Zinc phosphate was tested in an oral limit test according to OECD guidelines using Wistar rats. No mortality occurred and no signs of toxicity was observed. The LD₅₀ is >5000 mg zinc phosphate/kg bw.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

5 000 mg/kg bw

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Used in EU risk assessment for zinc oxide

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

not specified

Sex:

male/female

Details on test animals or test system and environmental conditions:

no information available

Route of administration:

inhalation

Type of inhalation exposure:

nose/head only

Vehicle:

other: no data

Analytical verification of test atmosphere concentrations:

not specified

Duration of exposure:

ca. 4 h

Concentrations:

Aerosol concentration was 5.7 mg/l

No. of animals per sex per dose:

10 per sex

Control animals:

yes

Details on study design:

10 male and 10 female animals per group were exposed to zinc oxide aerosol (head and nose only) for 4 h. Aerosol concentration was 5.7 mg/l and the particle size distribution had a mass median aerodynamic diameter of 4 µm ± 2.9 (GSD). Only one concentration and a control group were tested. All animals survived up to day 14 post exposure.

Statistics:

no information

Preliminary study:

no information

Sex:

not specified

Dose descriptor:

LC50

Effect level:

> 5 700 mg/m³ air

Exp. duration:

4 h

Mortality:

no mortality

Clinical signs:

other: only a dusty fur on the head, no adverse effects noted

Body weight:

no change in body weights observed

Gross pathology:

no adverse effects observed.

Other findings:

none observed

no information

Interpretation of results:

GHS criteria not met

Conclusions:

LC50 4 hours >5.7 mg ZnO/l

Executive summary:

In an acute inhalation toxicity study, 10 male and 10 female animals per group were exposed to zinc oxide aerosol (head and nose only) for 4 h. Aerosol concentration was 5.7 mg/l and the particle size distribution had a mass median aerodynamic diameter of 4mm ± 2.9 (GSD). Only one concentration and a control group were tested. All animals survived up to day 14 post exposure. Apart from a dusty fur on the head the day after the exposure, no effects were seen. Body weights developed normally. At pathological examination all organs were normal. The LC₅₀was >5.7 mg/l.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LC50

Value:

5 700 mg/m³ air

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance does not meet the criteria for classification as acute toxicity or STOT SE by the oral route and no systemic effects have been observed in in vivo studies with dermal exposure (e.g. skin irritation, skin sensitisation)

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Of significance for humans from an acute toxicity standpoint is the occurrence of metal fume fever following exposure to ultrafine particles of special grades of zinc oxide in context of very specific operations such as cutting or welding of galvanised steel. Metal fume fever is exclusively associated with freshly formed ultrafine particulate zinc oxide (<0.1 µm). As these ultrafine particles (nanoparticles) rapidly agglomerate to bigger particles, which are normally encountered at production and processing sites, at these sites there is no indication for metal fume fever. According to the response from 11 zinc companies to a questionnaire, there have been no observations of zinc metal fume fever over the last decade and in recent occupational practice (EU RAR, 2004a-f). However in light of responsible care and since no studies are available that allow the establishment of a NOAEL for metal fume fever with a reasonable degree of certainty, a LOAEL (5 mg ZnO/m³) for 2 hours (showed the typical metal fume fever symptoms beginning 4 to 8 hours after exposure and disappearing within 24 hours) can be used for metal fume fever based on the study by Gordon et al.(1992).

Justification for classification or non-classification

Based on the results of the available acute oral rat study, trizinc bis(orthophosphate) does not require classification for acute oral toxicity according to EU CLP criteria (EC 1272/2008).

Based on read across from the results of the available acute inhalation rat study with zinc oxide, trizinc bis(orthophosphate) does not require classification for acute inhalation toxicity according to EU CLP criteria (EC 1272/2008).

There are no available data on which to evaluate acute dermal toxicity. However, acute dermal toxicity can be considered low in view of the poor absorption by this route and the substance does not meet the criteria for classification as acute toxicity or STOT SE by the oral route. Therefore, trizinc bis(orthophosphate) does not require classification for acute dermal toxicity according to EU CLP criteria (EC 1272/2008)

No clear evidence of specific target organ toxicity was noted. As such, classification for STOT-SE is not considered appropriate.