Pyrithione zinc

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.2 (Acute Toxicity (Inhalation))

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPP 81-3 (Acute inhalation toxicity)

GLP compliance:

yes

Test type:

standard acute method

Test material

Test material information

Constituent 1

Reference substance name:

Pyrithione zinc

EC Number:

236-671-3

EC Name:

Pyrithione zinc

Cas Number:

13463-41-7

Molecular formula:

C10H8N2O2S2Zn

IUPAC Name:

Bis [1-hydroxy-2(1H)-pyridinethionato-O,S](T-4)-zinc

Details on test material:

Batch number: TOX1000
Description: off white powder

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

Source: Charles River UK
Age at study initiation: 8-10 weeks
Weight at study initiation: Male - 227-280g Female - 190-253g

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Details on inhalation exposure:

Post exopsure period: 14 days
Particle size: MMAD 3.8, 3.5 and 3.3 µm + GSD 0.41, 0.55 and 0.48 µm
Particle preparation: A dust atmosphere was produced using a "Wright`s Dust Feed" mechanism.

Duration of exposure:

4 h

Concentrations:

Nominal: 7.9, 3. 9 and 1.9 mg/L
Measured: 1.82, 0.95 and 0.53 mg/L

No. of animals per sex per dose:

5

Control animals:

no

Results and discussion

Effect levels

Effect levels 1

Sex:

female

Dose descriptor:

LC50

Effect level:

1.34 mg/L air

95% CL:

0.66 - < 2.73

Effect levels 2

Sex:

male

Dose descriptor:

LC50

Effect level:

0.84 mg/L air

95% CL:

0.54 - < 1.31

Effect levels 3

Sex:

male/female

Dose descriptor:

LC50

Effect level:

1.03 mg/L air

95% CL:

0.74 - < 1.43

Mortality:

Mortality: 5/5 males and 3/5 females exposed to 1.82 mg/L
3/5 males and 2/5 females exposed to 0.95 mg/L
1/5 males and 0/0 females exposed to 0.53 mg/L

Clinical signs:

other: Common abnormalities like wet fur, hunched posture, pilo-erection, decreased respiratory rate, pallor of the extremities and ptosis, incidents of lethargy, ataxia, laboured gasping and noisy respiration, red/brown staining around the eyes, snout and mouth

Body weight:

Bodyweight gain: During Week 1 incidents of bodyweight loss and reduced bodyweight gain in surviving animals but with the exception of one female, normal bodyweight development was noted during Week 2.

Gross pathology:

Lung abnormalities, excessive fluid in the thoracic cavity, liver changes, pale kidneys, incidents of congestion, reddening and gaseous distension in the gastro-intestinal tract were found in the animals that died or were killed in extremis. One female exposed to 0.53 mg/L showed dark foci on the lungs.

Applicant's summary and conclusion

Conclusions:

LC50 = 1.03 mg/l air. This information may not be used for any purpose other than in support of the Chemical safety Report submitted by Arch Chemicals Inc. under Regulation EC 1907/2006.