Lubricating oils (petroleum), base oils, paraffinic

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study summary report

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

review article or handbook

Title:

ROBUST SUMMARY OF INFORMATION ON LUBRICATING OIL BASESTOCKS

Author:

American Petroleum Institute

Year:

2003

Bibliographic source:

ROBUST SUMMARY OF INFORMATION ON LUBRICATING OIL BASESTOCKS pag 25-27

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

not specified

GLP compliance:

not specified

Test type:

other: APi method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Distillates (petroleum), hydrotreated light naphthenic

EC Number:

265-156-6

EC Name:

Distillates (petroleum), hydrotreated light naphthenic

Cas Number:

64742-53-6

IUPAC Name:

64742-53-6

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

not specified

Vehicle:

air

Analytical verification of test atmosphere concentrations:

not specified

Duration of exposure:

ca. 4 h

Concentrations:

1, 1.5, 2.5, 3.5 and 5 mg/l

No. of animals per sex per dose:

5

Control animals:

yes

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

ca. 2.18 mg/L air

Based on:

not specified

95% CL:

> 1.8 - < 2.55

Exp. duration:

4 h

Any other information on results incl. tables

Actual exposure concentrations and mortalities were as follows:

Target level	Actual concentration		Mortality
mg/l	mg/l	+/- SD	male	female
0	0.02	0.01	0/5	0/5
1	1.04	0.1	1/5	1/5
1.5	1.51	0.15	0/5	0/5
2.5	2.37	0.31	3/5	3/5
3.5	3.49	0.36	5/5	5/5
5	5.05	0.18	5/5	5/5

Particle size measurements confirmed that mass median aerodynamic diameter and geometric standard deviation values were in the ranges 1.7 to 2.5 mµ and 1.5 to 1.61 respectively. These measurements confirm that the particles were within the respirable range. The LC50 for combined sexes was estimated to be 2.18 with 95% confidence limits of 1.80 to 2.55 mg/l. Body weight differences did not show a consistent dose related pattern. At the highest concentration, the animals were obscured by a dense aerosol and observations could not be made during the exposure period. In other groups, there was a decreased activity, wet inguinal area, eyes partially closed, wet coat, loose stool and oily coat during exposure. During the first week post-exposure, similar signs were observed as well as signs of poor condition, respiratory distress and some deaths occurred. During test week 2, most survivors were considered to be of normal appearance. The signs that were observed occurred in a dose related manner.

At histology, affected animals exhibited diffuse pulmonary congestion and perivascular edema that were mostly moderate or marked in degree. Less consistently spotty alveolar edema was also seen. There was widespread damage to alveolar walls resulting in fibronecrotic debris resembling hyaline membranes in more marked cases and extravasation of RBCs and PMNs. Necrosis and inflammation were seen in the walls of small blood vessels and there was spotty epithelial necrosis in small bronchioles, but the most severe damage seemed to be centroacinar. The larger airways were relatively unaffected. None of the surviving animals exhibited the above acute changes. However, most of the surviving animals exposed to 2.5 or 1.0 mg/l and above exhibited chronic inflammatory changes that were not seen in the controls and only occasionally in animals exposed at the 1.5 mg/l level, and then to a lesser degree of severity. Other findings were considered sporadic or unrelated to exposure to the test material.