Zinc dilactate

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

Not reported

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1986

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Sprague-Dawley rats were exposed for 10 min to the test material followed by observations of clinical signs and mortality. After 7 d observation time animals were anesthetized and lungs were examined.

GLP compliance:

no

Test type:

other: Acute Inhalation Toxicity

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Zinc chloride

EC Number:

231-592-0

EC Name:

Zinc chloride

Cas Number:

7646-85-7

IUPAC Name:

zinc dichloride

Details on test material:

- Name of test material (as cited in study report): Zinc chloride

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: ALAB, Sollentuna, Sweden
- Age at study initiation: 60-80 d
- Weight at study initiation: 200-250 g

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22-23 °C
- Humidity (%): 50-60 %

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

head only

Vehicle:

other: water

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Inhalation chamber operated in dynamic mode
- Exposure chamber volume: 8.4 L
- Method of holding animals in test chamber: Perspex cylinders
- System of generating particulates/aerosols: Generated from a solution of test material in water (3.7 and 10.3 M with specific gravity 1.3 and 7.1 g/mL) by means of Collision nebulizer
- Method of particle size determination: Cascade impactors of the Battelle type (Mitchell and Pilcher 1959) using a sampling flow of 1 L/min

TEST ATMOSPHERE
- Brief description of analytical method used: Particles collected on membrane filters (Millipore, AAWP, pore size 0.45 µm), filters extracted in 4 M HNO3, extract analyzed by flame atomic absorption spectrometer (air-acetylene flame, 213.9 nm)
- Samples taken from breathing zone: Yes

TEST ATMOSPHERE (if not tabulated)
- Particle size distribution: Non-uniform
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): 2.3 and 2.6 µm

Analytical verification of test atmosphere concentrations:

yes

Remarks:

flame atomic absorption spectrometer (air-acetylene flame, 213.9 nm)

Duration of exposure:

10 min

Concentrations:

600, 940, 1220 and 1950 mg Zn/m³ (molar ratio of Zn: ZnCl2 is 1:2.1)

No. of animals per sex per dose:

Three

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 7 d
- Necropsy of survivors performed: Yes
- Other examinations performed: Clinical signs, mortality, gross pathology and histopathology

Statistics:

Not reported

Results and discussion

Preliminary study:

Not applicable

Effect levels

Effect levels 1

Sex:

female

Dose descriptor:

LC50

Effect level:

2 000 mg/m³ air (analytical)

Exp. duration:

10 min

Effect levels 2

Sex:

female

Dose descriptor:

other: LCt50

Effect level:

20 000 other: mg.min/m3

Exp. duration:

10 min

Mortality:

Two animals died at 940 and 1220 mg/m³ while all animals died at highest dose of 1950 mg/m³. For details see ‘table 1’ .

Clinical signs:

other: Respiratory distress including dyspnoea, decreased locomotor activity, laboured breathing, rhonci and rales observed.

Body weight:

Not reported

Gross pathology:

Entire surface of lungs showed discolouration (dark red), varying degrees of congestion, patchy discolouration, oedema and interstitial emphysema

Other findings:

- Histopathology: Atelectasis, hyperaemia and haemorrhages and oedema observed
- Potential target organs: Lungs

Any other information on results incl. tables

Table 1: Acute inhalation toxicity of test material in rats

Concentration (mg Zn/m³)*	Mortality after exposure during 10 min (number of deaths/exposed)
600	0/3
940	2/3
1220	2/3
1950	3/3

* The molar ratio of Zn:ZnCl₂ is 1:2.1

Applicant's summary and conclusion

Interpretation of results:

study cannot be used for classification

Conclusions:

Based on these results, the acute inhalation LC50 of the test material was calculated to be 2000 mg ZnCl2/m³ in rats after a exposure of 10 minutes.

Executive summary:

A study was conducted in female Sprague-Dawley rats to determine pulmonary injury after acute inhalation exposure to the test material.

Animals were exposed to the test material at a concentration of 600, 940, 1220 and 1950 mg Zn/m³ (molar ratio of Zn:ZnCl₂ is 1:2.1) for 10 min. Animals showed respiratory distress. Clinical examination of the lung showed discolouration (dark red), varying degrees of congestion, patchy discolouration, oedema and interstitial emphysema, atelectasis, hyperaemia and haemorrhages.

Based on the above results, the acute inhalation LC₅₀ of the test material in rats was calculated to be 2000 mg ZnCl₂/m³.