Perboric acid, sodium salt

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1987

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study well documented with GLP compliance, but data concerning macroscopic or histopathological examinations not reported

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:

The ALC (defined as the lowest atmospheric concentration tested that caused the death of 1 or more rats within 14 days of exposure) was calculated in this study. The 4-hours LC50 was re-calculated at a later stage

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

10486-00-7

EC Number:

600-611-8

Cas Number:

10486-00-7

IUPAC Name:

10486-00-7

Details on test material:

-Name of test material (as cited in study report): Perboric acid, sodium salt, tetrahydrate
-Physical state: White powder
-Purity: 98.6 %
-Lot/batch No.: 16,703 (Haskell Lab.)
-Other Code: 5# Fine SPBT D50 of 13.3 microns
-Stability under test conditions: Test material was assumed to be stable throughout the exposure phase of the test

Test animals

Species:

rat

Strain:

other: Crl:CD BR

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
-Source: Charles River Breeding Lab., Kingston, New York
-Age at study initiation: 8 weeks
-Weight at study initiation: 230 - 290 grams
-Fasting period before study: no data
-Housing: In pairs in stainless steel wire-mesh cages
-Diet: ad lib. (except during exposure)
-Water: ad lib. (except during exposure)
-Acclimation period: 1 week

ENVIRONMENTAL CONDITIONS
-Temperature (°C): 23 +/- 2
-Humidity (%): 50 +/- 10
-Air changes (per hr): no data
-Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

inhalation: dust

Type of inhalation exposure:

nose only

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
-Exposure apparatus: K-TRON Model T-20 Twin Screw Volumetric Feeder
-Exposure chamber volume: 6000 mL
-Method of holding animals in test chamber: Rats were restrained in stainless steel cylinders with conical nose piece
-Source and rate of air: ca. 24 - 36 L/min
-Method of conditioning air: High pressure air jet
-System of generating particulates/aerosols: The air flow swept the suspended dust into the 6000 mL cyclonic elutriator. The cyclone removed the larger particles by impaction and allowed the smaller particles to enter a 38 L glass exposure chamber.
-Method of particle size determination: By Sierra Series 210 cascade impactor (MMAD and percent particles with aerodynamic diameters less than 10 um)
-Temperature, humidity, pressure in air chamber: Chamber temperature was measured with a mercury thermometer, relative humidity with a Bendix Model 566 psychrometer, and chamber oxygen content with a Biosystem Model 3100R oxygen analyser

TEST ATMOSPHERE
-Brief description of analytical method used: In 30 min intervals by gravimetric analyses. Known volumes of chamber atmosphere were drawn through pre-weighed Gelman glass fiber filters. Filters were weighed on a Cahn 28 automatic Electrobalance. Atmospheric concentrations were calculated from the filter weight gain, determined from the pre- and post-sampling filter weights.
-Samples taken from breathing zone: yes

VEHICLE
None, air only

TEST ATMOSPHERE
-Particle size distribution: as tabulated below
-MMAD / GSD: as tabulated below

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

Mean: 160, 480, 1100 and 2900 mg/m3

No. of animals per sex per dose:

6

Control animals:

no

Details on study design:

-Duration of observation period following administration: 14 days
-Frequency of observations and weighing: daily clinical observation and weighing of all survivors
-Necropsy of survivors performed: no data

Statistics:

LC 50 was calculated separately by Probit Analysis

Results and discussion

Effect levels

Sex:

male

Dose descriptor:

LC50

Effect level:

1 165 mg/m³ air

Based on:

test mat.

95% CL:

>= 590 - <= 2 909

Exp. duration:

4 h

Mortality:

160 mg/m3: 0/6
480 mg/m3: 1/6
1100 mg/m3: 3/6
2900 mg/m3: 5/6

All deaths occurred within 24 hours.

Clinical signs:

other: During or immediately following exposure, rats from all groups exhibited gasping, red nasal discharge, and compound-covered faeces. Rats from the >= 480 mg/m3 groups also exhibited laboured breathing. In addition, rats from the >= 1100 mg/m3 groups did no

Body weight:

Rats typically had slight to severe (up to 18 % of initial body weight) weight losses within 24 hours of exposure.

Gross pathology:

No data

Any other information on results incl. tables

Sodium Perborate Tetrahydrate Atmospheres / Mortality

 

Concentration (mg/m3)			% Particles < 10 um AD^a	MMAD (um)^b	Mortality (# deaths/# exposed
Mean	SD	Range
160	23	140-210	94	3.3	0/6
480	130	280-640	94	3.5	1/6
1100	240	720-1500	93	3.5	3/6
2900	1500	870-4900	86	4.2	5/6

 

a: Percent by weight of particles with aerodynamic diameter (AD) less than 10 um

b: Mass median aerodynamic diameter

Applicant's summary and conclusion

Interpretation of results:

Category 4 based on GHS criteria

Remarks:

Migrated information

Conclusions:

The calculated LC50 in male rats over 4 hours was at 1165 mg/m3 of air.

Executive summary:

In this study, the 4 h inhalation ALC was calculated in male rats. Mean concentrations of Sodium Perborate Tetrahydrate were 160, 480, 1100 and 2900 mg/m3 and 6 males per dose were used. Mortality was dose-related and the ALC was determined with 480 mg/m3. The substance was classified as moderately toxic.

The LC50 (4 h) was calculated subsequent to the study report finalisation and was at 1165 mg/m3 (equivalent to toxicity category IV of GHS OECD or harmful according to Annex VI of Directive 67/548/EEC).