Naphthalene-2,6-dicarboxylic acid

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Rats received March 16, 1981 and final report issued July 9, 1981

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline 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:

EPA OPPTS 870.1300 (Acute inhalation toxicity)

GLP compliance:

yes

Test type:

traditional method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Naphthalene-2,6-dicarboxylic acid

EC Number:

214-527-0

EC Name:

Naphthalene-2,6-dicarboxylic acid

Cas Number:

1141-38-4

Molecular formula:

C12H8O4

IUPAC Name:

naphthalene-2,6-dicarboxylic acid

Test material form:

solid

Specific details on test material used for the study:

2,6-naphthalene dicarboxylic acid

Test animals

Species:

rat

Strain:

CD-1

Sex:

male/female

Details on test animals or test system and environmental conditions:

The albino rats used on this sudy were of Sprague-Dawley derived srain (Charles River CD) received from the Chrales River Breeding laboratories (Portage, MI) on March 16, 1981.TEST ANIMALS
- Source: Charles River Breeding laboratories (Portage, MI)
- Males and Females (nulliparous and non-pregnant)
- Age at study initiation: Males 54 days old; Females 61 days old
- Weight at study initiation: 245 g ± 10.4 g; Females 206 g ± 4.4 g
- Fasting period before study: none
- Housing: During quarantine period the rats were group-caged in suspended wire-mesh cages, segregated by sex. during ht eexposure and post-exposure periods the rats were caged individually and identified with individual monel metal ear tags.
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: one week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Controlled
- Temperature, humiditity (%): not stated specifically, but according to Guide for the Care and Use of Laboratory Animals (DHEW No. N.I.H. 74-23, 1974
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: To: April 1, 1981 to April 15, 1981

Administration / exposure

Route of administration:

inhalation: dust

Type of inhalation exposure:

whole body

Vehicle:

clean air

Mass median aerodynamic diameter (MMAD):

7.6 µm

Geometric standard deviation (GSD):

1.95

Remark on MMAD/GSD:

Andersen 8 stage cascade impactor

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Glass and stainless steel chambers.
- Exposure chamber volume: 160 L
- Method of holding animals in test chamber: Individual caged in suspended wire mesh cages
- Source and rate of air: from HVAC system, 80-90 L/min
- Method of conditioning air: filtered before entering dust generator
- System of generating particulates/aerosols: IRDC dust generator
- Method of particle size determination: Andersen 8 stage cascade impactor

TEST ATMOSPHERE (if not tabulated)
- Particle size distribution:
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.):

Analytical verification of test atmosphere concentrations:

no

Duration of exposure:

4 h

Remarks on duration:

Acutal exposure time 248 min (4.13 h)

Concentrations:

Single exposure at maximum air concentration sustainable

No. of animals per sex per dose:

5 males and 5 females

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Daily observations, weights prior to exposure and at 7 and 14 days
- Necropsy of survivors performed: yes, gross pathology

Statistics:

Mean and standard deviations for atmosphere concentration, particle size, and body weights

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LC50 cut-off

Effect level:

0.73 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

not determinable due to absence of adverse toxic effects

Mortality:

none

Clinical signs:

other: During exposure, all of the exposed animals were observed to have dyspnea. In for of the 10 animals this condition was also observed for the first day or two in the 14-day postexposure observation period.

Body weight:

All animals gained weight during the study. Males starting mean weight 245 g and end mean weight 321 g. Females starting mean weight 206 g and ending weight 249 g.

Gross pathology:

The only finding was the gross observation of varying shades of red areas on the lungs of three male rats.

Other findings:

None

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

No animals died during the in life phase of the study, during or after exposure to 0.73 µg/L of 2,6-naphthalene dicarboxylic acid. As such, the LC50 is above 0.73 µg/L.

Executive summary:

The study consisted of a single group of five male and five female albino rats. This group was exposed for approximately 4 hours to a dust aerosol atmosphere containing 0.73 mg/L of 2,6 -naphthalene dicarboxylic acid with an aerodynamic diameter of 7.6 µM with a geometric standard deviation of 1.95. All animlas were observed during the exposure and postexposure period. body weights were recorded prior to exposure and at 7- and 14 -days postexposure. The only pharmacotoxic sign noted during and after exposure was dyspnea. All animals gained weight and survived the until the scheduled sacrifice, where they underwent a gross necropsy wherein all major organs in the abdominal and thoraic cavities were observed for macroscopic abnormalities. The only notable finding during gross necropsy as red areas in the lungs of three male rats.