6-hydroxy-2-naphthoic acid

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: No GLP statement; However, is a well-conducted, well-documented study.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1981

Report date:

1981

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

no

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

6-hydroxy-2-naphthoic acid

EC Number:

240-759-7

EC Name:

6-hydroxy-2-naphthoic acid

Cas Number:

16712-64-4

Molecular formula:

C11H8O3

IUPAC Name:

6-hydroxynaphthalene-2-carboxylic acid

Constituent 2

Reference substance name:

C-195

IUPAC Name:

C-195

Constituent 3

Reference substance name:

6-HNA

IUPAC Name:

6-HNA

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): C-195
- Substance type: Solid
- Physical state: Powder
- Analytical purity: Not stated
- Impurities (identity and concentrations): Not stated
- Composition of test material, percentage of components: Not stated
- Lot/batch No.: Not given
- Expiration date of the lot/batch: Not given
- Stability under test conditions: Not stated
- Storage condition of test material: Not stated
- Other:

Test animals

Species:

rat

Strain:

Crj: CD(SD)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Strain: Sprague-Dawley derived CD
- Source: Charles River Breeding Laboratories, Wilmington, MA, USA
- Date received: 29 July 1980
- Age at study initiation: Not given
- Weight at study initiation: Males, 290-300 grams; Females, 210-249 grams
- Fasting period before study: Not stated.
- Housing: Not stated.
- Diet (e.g. ad libitum): Not stated.
- Water (e.g. ad libitum): Not stated.
- Acclimation period: Not stated.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): mean temperature was 21 degrees C during exposure.
- Humidity (%): mean relative humidity was 74% during exposure.
- Air changes (per hr): Not given. Study report gives air flow rate of "15 liters per minute" and states that "test material was delivered in a total volume of 3600 L of air".
- Photoperiod (hrs dark / hrs light): Not stated.

IN-LIFE DATES: Not stated.

Administration / exposure

Route of administration:

inhalation: dust

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Plexiglass Exposure Chamber
- Exposure chamber volume: 100 L
- Method of holding animals in test chamber: Closed Chamber
- Source and rate of air: Source not stated, rate given as 15 liters per minute.
- Method of conditioning air: Described only as "dry air".

- System of generating particulates/aerosols: Test material was press-packed into a Wright Dust Feed cylinder using a Carver Hydraulic Press at a pressure of 1500 psi. The Wright Dust Feed mechanism, set at a gear ratio of 1.5 to 1 was arranged to feed into the exposure chamber. Dry air at a flow rate of 15 liters per minute was passed through the dust feed mechanisms to generate the dust, which was directed undiluted into the exposure chamber.

- Method of particle size determination: Particle size distribution samples were taken at half-hour intervals using a Casella cascade impactor. The distribution was calculated based on the amount of material collected on the impactor stages.

- Treatment of exhaust air: Not stated.
- Temperature, humidity, pressure in air chamber: mean chamber temperature of 21 degrees C, and relative humidity of 74% during exposure.

TEST ATMOSPHERE
- Brief description of analytical method used:
- Samples taken from breathing zone: yes/no

VEHICLE
- Composition of vehicle (if applicable): Air
- Concentration of test material in vehicle (if applicable): mean airborne test material concentration given as 0.51 mg/Liter air.
- Justification of choice of vehicle: Most relevant vehicle for this route of administration.
- Lot/batch no. (if required): Not applicable.
- Purity: Not given.

TEST ATMOSPHERE (if not tabulated)
- Particle size distribution: Not given.
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): Aerodynamic Mass Median Diameter of 3.61 micron, with Geometric Standard Deviation Range of 2.21 to 6.55.

Analytical verification of test atmosphere concentrations:

yes

Remarks:

Total airborne concentration measured hourly.

Duration of exposure:

4 h

Concentrations:

Nominal concentration of 3.8 mg/Liter.

No. of animals per sex per dose:

5 animals per sex, only one dose level evaluated.

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days.
- Frequency of observations and weighing: Animals were observed for abnormal signs before exposure, every 15 minutes during the first hour of exposure, hourly through the rest of the exposure period, hourly for four hours post-exposure, and daily thereafter for 14 days.
- Necropsy of survivors performed: yes
- Other examinations performed:

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

other: slight reversible irritation of the oral and respiratory mucous membranes.

Effect level:

3.8 mg/L air (nominal)

Based on:

test mat.

Exp. duration:

4 h

Mortality:

No animals died during the exposure period, or the during the subsequent 14-day observation period.

Clinical signs:

other: During exposure, animals were noted to be "huddled together in the chamber." In addition, some animals were observed to be rubbing their eyes, and some were noted to have labored breathing and wet and/or matted fur. After removal from the chamber, most

Body weight:

Although small, transient weight losses were observed in most rats, body weights recovered to pre-exposure values in Males by Day 7, and in females by Day 14.

Gross pathology:

At necropsy, 4 males and 3 females showed foci of lung discoloration. However, these were determined to be common pathological entities in this particular strain of rats, and was deemed to not be related to the test material.

Applicant's summary and conclusion

Interpretation of results:

relatively harmless

Remarks:

Migrated information Criteria used for interpretation of results: expert judgment

Conclusions:

A four-hour acute inhalation exposure to a dust of test material at a nominal concentration of 3.8 mg/L with an aerodynamic mass median diameter of 3.61 microns and geometric standard deviation range of 2.21 to 6.55 did not produce mortality, but caused a slight reversible irritation of the oral and respiratory mucous membranes. Also observed was slight neuro-muscular impairment during the 4 hour post-exposure observation period.

Executive summary:

A four-hour acute inhalation exposure to a dust of test material at a nominal concentration of 3.8 mg/L with an aerodynamic mass median diameter of 3.61 microns and geometric standard deviation range of 2.21 to 6.55 did not produce mortality, but caused a slight reversible irritation of the oral and respiratory mucous membranes. Also observed was slight neuro-muscular impairment during the 4 hour post-exposure observation period.