Chlorine

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Deficiencies: max. duration of treatment only 0.5 hour, no batch number indicated.Although some aspects of the study do not meet up-to-date standards, the results are reliable and allow a scientific valid evaluation of this toxicological endpoint. New studies are therefore not required and should not be conducted due to animal welfare considerations.

Cross-reference

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1987

Report date:

1987

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

yes

Remarks:

Short exposure time (max. 30 min.)

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Chlorine

EC Number:

231-959-5

EC Name:

Chlorine

Cas Number:

7782-50-5

Molecular formula:

Cl2

IUPAC Name:

dichlorine

Details on test material:

- Name of test material (as cited in study report): Chlorine - Analytical purity: 99.9 %- Impurities (identity and concentrations): Traces of Fe2(SO4)3- Lot/batch No.: Not stated - Stability under test conditions: Not stated- Traces of Fe2(SO4)3

Test animals

Species:

mouse

Strain:

Swiss

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS- Source: Charles River France SA, Saint Aubin les Elboeuf, France- Age at study initiation: Not stated- Weight at study initiation: mean weight 31.2 g (males); 25.3 g (females).

Administration / exposure

Route of administration:

inhalation: gas

Type of inhalation exposure:

whole body

Vehicle:

other: air

Details on inhalation exposure:

Duration of exposure:Group B, H, J, N, V and T: 10 min.Group R, E, K, C and Z: 30 min.

Duration of exposure:

>= 10 - <= 30 min

Concentrations:

Group B: 1680 mg/m3 (1.68 mg/L)Group C: 1757 ± 35 mg/m3 (1.757 mg/L)Group E: 1586 ± 47 mg/m3 (1.586 mg/L)Group H: 2186 ± 81 mg/m3 (2.186 mg/L)Group J: 2363 ± 81 mg/m3 (2.363 mg/L)Group K: 1665 ± 32 mg/m3 (1.665 mg/L)Group N: 3485 mg/m3 (3.485 mg/L)Group R: 1328 ± 55 mg/m3 (1.328 mg/L)Group T: 4798 mg/m3 (4798 mg/L)Group V: 3826 ± 38 mg/m3 (3.826 mg/L)Group Z: 1870 ± 21 mg/m3 (1.87 mg/L)

No. of animals per sex per dose:

5 per sex and group

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days- Frequency of observations and weighing: performed on days 1, 2, 4, 7 and 14- Necropsy of survivors performed: yes- Other examinations performed: clinical signs, Mortalities, gross autopsy, body weights, weight of kidneys, liver, and lungs, lung and conductive airways were preserved for microscopic examination

Statistics:

Method of determination of LD50:Response-concentration-time relationship was used to estimate the LC50 values

Results and discussion

Effect levels

Effect levels 1

Sex:

male/female

Dose descriptor:

LC50

Effect level:

3 064 mg/m³ air

95% CL:

2 560 - 3 657

Exp. duration:

10 min

Effect levels 2

Sex:

male/female

Dose descriptor:

LC50

Effect level:

1 462 mg/m³ air

95% CL:

1 198 - 1 671

Exp. duration:

30 min

Mortality:

For mortalities please refer to table below.

Clinical signs:

other: Wet nares, bubble formation and nasal discharge (mainly in the highest concentration group)

Body weight:

Both male and female mice lost body weight during the first 2 days after exposure which is a common finding in this type of experiment. After day 4 most animals gained body weight again but weight gain was generally low.

Gross pathology:

Not stated

Other findings:

Organ weights:Relative lung weights were generally increased. For kidneys and liver no dose related effects were seen.

Any other information on results incl. tables

Mortality rates

Group	Concentration (mg/L)±SD^a	Exposure time (min.)	Mortality rate (%)	Day of death (number)
B	1.680±0	10	0	-
H	2.186±81	10	0	-
J	2.363±81	10	30	6(1); 13(2)
N	3.485±0	10	40	0(2); 10(1); 13(1)
V	3.826±38	10	100	0(8); 1(2)
T	4.798±0	10	100	0(10)
R	1.328±55	30	40	0(1); 8(2); 13(1)
E	1.586±47	30	70	0(4); 8(1); 9(1); 11(1)
K	1.665±32	30	60	0(2); 1(2); 9(1); 11(1)
C	1.757±35	30	90	0(5); 10(3); 13(1)
Z	1870±21	30	70	0(3); 1(2); 8(2)

^a      SD: Standard deviation

Applicant's summary and conclusion

Interpretation of results:

Category 3 based on GHS criteria

Remarks:

Migrated information

Conclusions:

Most of the effects of chlorine occurred in the alveoli. Exposure to chlorine resulted additionally in changes in the conductive airways in some animals.The LC50 value for 30 min. exposure was derived at 1.462 mg/L.

Executive summary:

MATERIALS AND METHODS

11 groups of 5 male and 5 female mice were exposed to different concentrations of chlorine for 10, or 30 min. After exposure the animals were observed for 14 days (signs of intoxication, mortalities, and body weights on days 1,2,4,7 and 14). After the observation period they were killed and subjected to a gross post mortem examination. The lung and conductive airways from selected animals were preserved for microscopic examination. Weight of kidneys, liver, and lungs was determined.

RESULTS AND DISCUSSION

The clinical observation of nasal discharge with bubble formation indicates an increase in discharge of mucus from the respiratory tract. This can be explained by the irritative nature of Cl₂. Foamy discharges usually indicate lung oedema. Swollen lungs possibly indicative of oedema were observed in animals which were examined closely after spontaneous death and after the scheduled kill in the satellite groups. However, for appraisal of acute oedema the lungs have to be cut to show the superfluous fluid which was not done since it is incompatible with fixation of the lungs for microscopic examination. With reference to the LC50 derivation no sex difference was observed. For pathological examinations please refer to 4.2. The loss of body weight is a common finding in this type of experiment. After day 4 most animals gained body weight again but weight gain was low. Relative organ weights were generally increased. The increase was positively correlated with the concentration level and the duration of exposure. For kidneys and liver no dose related effects were seen.