Tetrapotassium pyrophosphate

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

August 1993

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1993

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: FMC Acute Inhalation Toxicity Protocol Number 27

Deviations:

yes

Remarks:

- minor deviations: the chamber and room humidity was slightly higher than recommended in the guideline

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

not specified

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: US EPA Toxic Substances Health Effect Test Guidelines, October, 1984; (PB82-232984) Acute Inhalation Toxicity Study.

Deviations:

not specified

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: Commission of the European Communities, Council Directive 67/548/EEC, Annex V, Part B.2.; May 1, 1987

Deviations:

not specified

Test guideline 5

Qualifier:

according to guideline

Guideline:

other: US EPA Pesticide Assessment Guidelines: Subdivision F, Hazard Evaluation: Human and Domestic Animals, Nov, 1984; 81-3 Acute Inhalation Study

Deviations:

not specified

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Tetrapotassium pyrophosphate

EC Number:

230-785-7

EC Name:

Tetrapotassium pyrophosphate

Cas Number:

7320-34-5

Molecular formula:

H4O7P2.4K

IUPAC Name:

tetrapotassium diphosphate

Details on test material:

- Name of test material (as cited in study report): Tetrapotassium Pyrophosphate
- Substance type: White powder
- Physical state: Solid
- Analytical purity: Not determined
- Reference No.: C600A3120N
- Storage: Room Temperature
- Other:
FMC-T#: 1042
Date received: April 26, 1993

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Kingston, NY on August 30, 1993.
- Age at study initiation: The actual age of the rats was not specified, only that they were young adults.
- Weight at study initiation (± SD): Males: 229 ± 7.8 g; Females: 220 ± 7.0 g
- Fasting period before study: No data
- Housing: Animals were housed individually in stainless steel suspended rat cages. Deosorb bedding was used in the litter pans.
- Diet: Purina Laboratory Rodent Chow 5001 available ad libitum
- Water: Tap water available ad libitum
- Acclimation period: Minimum of 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 - 23 °C (quoted in the study as 69 - 73 °F)
- Humidity (%): 42 - 74%
- Air changes (per hr): 12.4 air changes per hour
- Photoperiod (hrs dark / hrs light): 12 h fluorescent light and 12 h dark cycle

Administration / exposure

Route of administration:

inhalation: dust

Type of inhalation exposure:

whole body

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: The Rochester type exposure chamber was made of stainless steel and glass and was operated dynamically. The calculated 99% equilibrium time for the chamber at a flow rate of 30.9 L per minute was 22.4 minutes (equivalent to 12.4 "air changes per hour").
- Exposure chamber volume: 150 L
- Method of holding animals in test chamber: The test animals were assigned to and housed in individual compartments of a wire mesh cage bank (all on the same horizontal level) during the exposure. The cage position assignment ensured equal distribution of both sexes throughout the cage bank.
- Source and rate of air: Breathing grade compressed air was used and the total chamber air flow rate was 30.9 L/minute.
- Method of conditioning air: no data
- System of generating particulates/aerosols: The test material was generated using a BGI Wright dust feeder II. The test material was dessicated and packed into large dust cups. Breathing Grade compressed air was metered to the Wright dust feeder through 1/4" teflon tubing by a Matheson® 605 rotameter with a metal float. Rotameter back pressure was monitored using a Marshalltown backpressure guage. The test material was made airborne by the compressed air dispersing the material into the exposure chamber. The concentration of the test atmosphere was controlled by the delivery rate setting of the Wright dust feeder.
- Method of particle size determination: The samples were drawn through a Sierra 218 cascade impactor at 2.78 liters per minute. The aerodynamic particle size distribution was determined by gravimetric analysis of the amount of test material collected on the impactor stages and subsequent determination of the mass median aerodynamic diameter (MMAD), geometric standard deviation and other particle size parameters by logarithmic-probability plotting.
- Treatment of exhaust air: The chamber air was exhausted from the bottom of the chamber and passed through an orifice tube system which continuously monitored airflow and then through a commercial filter box. The filter box was connected to a line leading to additional filters and an exhaust fan on the roof. The exhaust operated at a flow rate of 30.9 liters per minute, creating a slight negative pressure in the chamber, which was considered to be the total chamber air flow rate. The entire exposure system and primary exhaust filter were contained in a fume hood.
- Temperature, humidity, pressure in air chamber: The mean temperature and relative humidity in the chamber were 22.2 °C (72 °F) and 49%, respectively. The pressure in the air chamber was not measured.

TEST ATMOSPHERE
- Brief description of analytical method used: The airborne concentration of the test material was determined gravimetrically.
- Samples taken from breathing zone: Yes - Chamber air samples were taken on Gelman® Type A/E 47 mm glass fiber filters held in cassettes at approximately one hour intervals during the exposure to determine the airborne concentration of test material. The airborne concentration of the test material was determined gravimetrically by drawing a known amount of chamber air through the filter. The samples were taken from the center of the chamber directly over the animal exposure caging.
The difference between gravimetric and nominal concentration was attributed to sedimentation of larger particles and/or adhesion of the test material to surfaces in the exposure chamber.

VEHICLE
- Not applicable: The test material was administered as received and a vehicle was not used.

TEST ATMOSPHERE (if not tabulated)
- Particle size distribution: The fraction of particles less than or equal to 1 µm in mass aerodynamic diameter, based on the log-probability graphs, ranged from 0.0 to 3.2%. The fraction of particles less than or equal to 10 µm in mass aerodynamic diameter, based on the log probability graphs, ranged from 81.6 to 83.7%. These results indicated the test material was respirable in size to the rat.
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): The MMADs ranged from 4.48 to 4.69 micrometers (µm) with geometric standard deviations ranging from 2.16 to 2.43. The MMAD represents the smallest size that could be achieved in this study. The material is hygroscopic causing the particles to agglomerate and/or adhere to surfaces inside the chamber. Several trials were initially performed with various generation schemes and the system which was ultimately chosen provided the best performance.

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

Nominal concentration: 28.8 mg/L (maximum attainable concentration)
Gravimetric concentration: 1.10 ± 0.054 mg/L

No. of animals per sex per dose:

5/sex/dose

Control animals:

no

Details on study design:

- Duration of observation period following administration: 21 days
- Frequency of observations and weighing: The animals were observed for signs of toxicity and mortality at fifteen minute intervals during the first hour of exposure, hourly for the remainder of the exposure, upon removal from the chamber, at one hour post-exposure, twice daily thereafter for twenty days and once on day 21. The observation period was extended to allow for abatement of clinical signs.
Individual bodyweights were recorded on days 0, 1, 2, 4, 7, 14 and 21. Animals dying intercurrently were weighed upon discovery of death.
- Necropsy of survivors performed: yes
- Other examinations performed:
Clinical signs noted during the exposure included lacrimation, material on fur, oral discahrge and squinting eyes.
Clinical signs noted upon removal from the chamber and at one hour post exposure included chromodacryorrhea, decreased locomotion, lacrimatino, material on fur, oral discharge, rales and squinting eyes.
Clinical signs noted during the 21 day post-exposure observation period included abdominogenital staining, alopecia on head, bloody oral discharge, chromodacryorrhea, chromorhinorrhea, dyspnea, decreased feces, dehydration, decreased locomotion, emaciated, lacrimation, material on fur, nasal discharge, no feces, opacity, rales, scab on snout, squinting eyes and unthriftiness.

Statistics:

No data

Results and discussion

Preliminary study:

Not applicable

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 1.1 mg/L air

Exp. duration:

4 h

Mortality:

One female died on day 6 post-exposure

Clinical signs:

other: See Table 1. Incidence of clinical signs was highest at the removal from chamber observation. Clinical signs generally persisted up to day 13 post-exposure and then gradually subsided. The observation period was extended to allow for abatement of clinica

Body weight:

See Table 2 and 3.
Most animals lost weight through day 4 of the study then began to gain weight in a normal pattern. At termination all surviving animals exhibited increases in body weight over their day 0 values.

Gross pathology:

See Table 4.
There was no gross internal lesions noted in any animal which survived to study termination. The animal that died on day 6 post-exposure had all lobes and surfaces of the lungs mottled dark red and red.

Other findings:

no data

Any other information on results incl. tables

Table 1 - Incidence of clinical signs – male

 

Observation	Day 0										Day 1		Day 2		Day 3
	Hour
	PT	0.25	0.50	0.75	1	2	3	4	R	1PE	AM	PM	AM	PM	AM	PM
Abdominogenital staining	0	0	0	0	0	0	0	0	0	0	5	5	5	5	5	5
Chromodacryorrhea	0	0	0	0	0	0	0	0	5	2	2	2	2	2	2	2
Decreased feces	0	0	0	0	0	0	0	0	0	0	0	0	1	1	1	1
Dehydration	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1	1
Decreased locomotion	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	0
Emaciated	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Lacrimation	0	5	5	5	5	5	5	5	3	2	1	1	0	0	0	0
Material on Fur	0	0	5	5	5	5	5	5	5	5	5	5	5	5	5	5
Opacity	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Oral discharge	0	0	0	3	3	3	3	3	5	1	0	0	0	0	0	0
Rales	0	0	0	0	0	0	0	0	1	1	0	0	0	0	0	0
Scab on Snout	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Squinting Eyes	0	5	5	5	5	5	5	5	3	3	2	2	2	2	2	2
Unthriftiness	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Death (cumulative)	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

Table 1 continued - Incidence of clinical signs - male

Observation	Day
	4		5		6		7		8		9		10		11
	AM	PM	AM	PM	AM	PM	AM	PM	AM	PM	AM	PM	AM	PM	AM	PM
Abdominogenital staining	3	3	3	2	1	1	0	0	0	0	0	0	0	0	0	0
Chromodacryorrhea	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Decreased feces	3	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Dehydration	1	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Decreased locomotion	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Emaciated	0	3	3	3	0	0	0	0	0	0	0	0	0	0	0	0
Lacrimation	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Material on Fur	5	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Opacity	0	1	1	1	1	1	2	2	2	2	2	2	2	2	2	2
Oral discharge	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Rales	0	1	1	1	0	0	0	0	3	3	3	3	2	1	0	0
Scab on Snout	1	1	1	1	1	1	1	1	1	1	1	1	0	0	0	0
Squinting Eyes	2	1	1	0	0	0	0	0	0	0	0	0	0	0	0	0
Unthriftiness	0	5	4	4	3	1	1	1	1	1	1	1	0	0	0	0
Death (cumulative)	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of this study, the test material caused mortality in one Sprague Dawley rat when administered for four hours at a mean, maximum attainable concentration of 1.10 mg/L. Based on this, the LC50 for Tetrapotassium pyrophosphate is considered to be greater than 1.10 mg/L.
This study is considered to be acceptable for classification and labelling in accordance with Regulation (EC) No 1272/2008 (EU CLP) and as such tetrapotassium pyrophosphate is not considered to be acutely toxic via the inhalation route (EU CLP).

Executive summary:

no data