Di-tert-pentyl peroxide

Endpoint summary

Description of key information

Acute oral toxicity:

Two well conducted studies are available for this endpoint (Doubs, 1995; Rees, 1992). Both are Klimisch 1, conducted according to OECD 401 (or similar to) and limit tests. In the study of Doubs (1995), 5 male rats and 5 female Sprague Dawley rats were dosed with 5000 mg/kg undiluted di-tert-amyl peroxide (purity close to 100 %). No mortality occurred. The most notable clinical abnormalities observed during the study included soft stools, decreased defecation, and fecal/urine stain. Body weight gain was noted for all animals during the test period. No significant gross internal findings were observed at necropsy.

In the study of Rees (1992), 5 male rats and 5 female Sprague Dawley rats were dosed with 2000 mg/kg Trigonox 201, equivalent to 1700 mg/kg di-tert-amyl peroxide. No mortality occurred during these two limit tests, no effect were observed on bodyweight gain. No significant gross internal findings were observed at necropsy.

 

Acute dermal toxicity:

The acute dermal toxicity of di-tert-amyl peroxide was evaluated in rats according to a method similar to OECD 402 (Doubs, 1995). The test item was applied to the skin of ten Sprague-Dawley rats (five males and five females) at the dose-level of 2000 mg/kg in semi-occlusive dressing for 24 hours. Animals were then observed during 14 days for mortality, clinical signs, and effects on body weight and then necropsied. No mortality occurred during the limit test. The most notable clinical abnormalities observed during the study included urine stain and dark material around the facial area, which occurred during the 24 hour exposure period. Dermal irritation was noted at the site of test article application. Body weight loss was noted for two female rats during the study day 0-7 interval and for one female during the study day 7-14 interval. Body weight gain was noted for all other animals during the test period. No significant gross internal findings were observed at necropsy on study day 14. Under the experimental conditions, the dermal LD0 of the test item Di-tert-amyl peroxide is higher than 2000 mg/kg in male/female rats.

 

Acute inhalation toxicity:

There is no data on acute inhalation toxicity on di-tert-amyl peroxide. A read across with di-tert-butyl peroxide is proposed to fulfill this data gap.

In an acute toxicity study by inhalation on di-tert-butyl peroxide, conducted according to OECD 436 guideline, groups of 3 male and 3 female albino rats was exposed by nose-only for 4 hours to vapors of the test item at a chemically determined concentration of 23 mg/L air (Pothmann, 2010). All animals survived the scheduled observation period. Tachypnea and shivering were recorded during exposure until 1 hour after exposure end. Ruffled fur was observed after exposure on test day 1 and test day 2. There were no clinical signs from test day 3 onwards. There were slight effects on body weight from test day 1 to 4. No macroscopic findings were recorded during necropsy. The inhalation LC0 of di-tert-butyl peroxide was estimated to be greater than 22 mg/L air.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories
- Age at study initiation: young adult
- Weight at study initiation: 245-277 g (male); 209-223 (female)
- Fasting period before study: overnight
- Housing: The animals were housed individually in suspended stainless steel cages.
- Identifiecation with metal ear tags
- Diet : ad libitum excepting during fasting
- Water: ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature and Humidity: The animal room temperature and relative humidity ranges were 62-74° F and 52-76%, respectively
- Air changes (per hr): There were 10-15 air changes in the animal room per hour. The animal room temperature and relative humidity were recorded a minimum of once daily. Environmental control equipment was monitored and adjusted as necessary to minimize fluctuations in the animal room environment
- Photoperiod: 12 hrs dark / 12 hrs light

Protocol Deviations:
The temperature and relative humidity of the animal room (62-74° F and 52-76%, respectively) exceeded the ranges specified in the protocol (65-79° F and 40-70%, respectively) during this study. ln addition, animals were apparently fed expired feed (6/18/95) from day 0 to day 2. These occurrences are considered to have had no adverse effect on the outcome of this study.

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

DOSE VOLUME APPLIED: 6.17 mL/Kg

Doses:

5000 mg/kg

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: mortality check: twice daily, clinical abnomrality observations: once daily. Weighting: prior to exposure, and on day 7 and 14
- Necropsy of survivors performed: yes

Sex:

male/female

Dose descriptor:

LD0

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality

Clinical signs:

other: The most notable clinical abnormalities observed during the study included soft stools, decreased defecation, and fecal/urine stain.

Gross pathology:

No significant gross internal findings were observed at necropsy on study day 14.

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of this test, the acute oral LD0 of Di-t-Amyl Peroxide was estimated to be greater than 5000 mg/kg in the rat.

Executive summary:

The Acute oral toxicity of di-tert-amyl peroxide was evaluated in rats in a limit test similar to OECD N°401 guideline. Groups of 5 male and 5 female Sprague Dawley rats were given a single oral dose of 5000 mg/kg. Following treatment, rats were observed daily and weighted weekly. A gross necropsy examination was performed at the time of scheduled euthanasia (Day 14). No mortality occurred during the limit test.  The most notable clinical abnormalities observed during the study included soft stools, decreased defecation, and fecal/urine stain. Body weight gain was noted for all animals during the test period. No significant gross internal findings were observed at necropsy on study day 14. Under the conditions of this test, the acute oral LD0 of Di-t-Amyl Peroxide was estimated to be greater than 5000 mg/kg in the rat.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

5 000 mg/kg bw

Quality of whole database:

Klimisch 1 study, GLP compliant.

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

experimental starting date: 09-Mar-2010, experimental completion date: 30-Mar-2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results. The study report was conclusive, done to a valid guideline and the study was conducted under GLP conditions. The read across justification is given in the iuclid, section 7.12.

Qualifier:

according to guideline

Guideline:

OECD Guideline 436 (Acute Inhalation Toxicity: Acute Toxic Class Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories Ltd, Kreuzelweg 53, 5961 NM Horst / Netherlands
- Age at study initiation: 9-10 weeks
- Weight at study initiation: males: 269.3 to 286.2 g, females: 178.1 to 187.9 g
- Fasting period before study: none
- Housing: nimals were housed in groups of 5 of the same sex in Makrolon® type-IV cages with wire mesh tops and standard softwood bedding ("Lignocel" J. Rettenmaier & Söhne GmbH & Co KG, 73494 Rosenberg / Germany, imported by Provimi Kliba AG, 4303 Kaiseraugst / Switzerland).
- Diet (e.g. ad libitum): Animals had ad libitum access to a pelleted standard Teklad rat maintenance diet (Provimi Kliba AG, 4303 Kaiseraugst, Switzerland) batch no. 82/09 except during the period when the animals were restrained in exposure tubes
- Water (e.g. ad libitum): Community tap water from Füllinsdorf ad libitum in water bottles, except during the period when they were restrained in exposure tubes.
- Acclimation period: at least five days under laboratory conditions, after clinical health examination

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3 °C,
- Humidity (%): 30-70%
- Air changes (per hr):10-15
- Photoperiod (hrs dark / hrs light): 12/12

Animal Welfare:
This study was performed in an AAALAC-accredited laboratory in accordance with the Swiss Animal Protection Law under license no. 397

IN-LIFE DATES: From: To: 09-Mar-2010 to 23-Mar-2010

Route of administration:

inhalation: vapour

Type of inhalation exposure:

nose only

Vehicle:

clean air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: The test atmosphere was generated using a Hudson nebulizer connected to a syringe pump. The polyethylene injector inside the nebulizer was replaced by a stainless steel injector
- Exposure chamber volume: not applicable
- Method of holding animals in test chamber: The animals were confined separately in restraint tubes which were positioned radially around the flow-past, nose-only exposure chamber
- Source and rate of air: compressed air was supplied by means of an oil free compressor and passed respiratory quality filters before it was introduced into the exposure system
- Method of conditioning air: respiratory quality filters
- System of generating particulates/aerosols: The test atmosphere was generated using a Hudson nebulizer connected to a syringe pump. The polyethylene injector inside the nebulizer was replaced by a stainless steel injector
- Method of particle size determination: not applicable
- Treatment of exhaust air: filtered
- Temperature, humidity, pressure in air chamber: 22.9 °C, 2.7 % rel humidity, 20.5 % oxygen

TEST ATMOSPHERE
- Brief description of analytical method used: Chemical determinations of vapor concentration were performed four times during exposure. The samples were drawn through a wash-bottle containing approximately 100 mL of Tetrahydrofuran. The wash-bottle was kept cool in water ice during sampling. An aliquot of each wash-bottle was forwarded in a cool box to the responsible scientist for analytical chemistry and stored frozen until analysis. The samples were analyzed using a GC method supplied by the Sponsor and implemented at Harlan Laboratories Ltd.
- Samples taken from breathing zone: yes

VEHICLE
- Composition of vehicle (if applicable):
- Concentration of test material in vehicle (if applicable):
- Justification of choice of vehicle:
- Lot/batch no. (if required):
- Purity:

TEST ATMOSPHERE (if not tabulated)
- Particle size distribution: as the test item was administered as a vapour no particle size determination was performed
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.):

CLASS METHOD (if applicable)
- Rationale for the selection of the starting concentration:

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

nominal aerosol concentration was 22 mg/L air
chemical aerosol concentration was 23 mg/L air

No. of animals per sex per dose:

3

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Observations for viability were recorded once before exposure on the day of exposure (test day 1), three times during exposure, immediately and 1 h after exposure on test day 1 and twice daily during the observation period.
Each animal was examined three times during exposure, immediately and 1 h after exposure on test day 1 and once daily during the observation period. Observations were detailed and carefully recorded using explicitly defined scales as appropriate. Only grossly abnormal signs were detectable during exposure, as the animals were restrained in the exposure tubes. The body weight of each animal was recorded on test days 1 (before exposure), 2, 4, 8 and 15 (before necropsy).

- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Statistics:

no

Sex:

male/female

Dose descriptor:

LC0

Effect level:

> 22 mg/L air (nominal)

Based on:

test mat.

Exp. duration:

4 h

Mortality:

none

Clinical signs:

other: Shivering and tachypnea during exposure were recorded in all animals. Tachypnea persisted until one hour after exposure end. Shivering was also recorded immediately after exposure end in all females. Ruffled fur was observed in all animals from 1 hour aft

Body weight:

From test day 1 to test day 2, slight body weight loss was noted in two males and one female. Stagnation of body weight was observed in one male and one female during the same period. Thereafter normal body weight development was recorded in these animals, except for two females. Slight body weight loss was recorded in one of these females and stagnation of body weight in the other female from test day 2 to test day 4.

There were no effects on body weight in the remaining female.
From test day 1 to test day 2, slight body weight loss was noted in two males and one female. Stagnation of body weight was observed in one male and one female during the same period. Thereafter normal body weight development was recorded in these animals, except for two females. Slight body weight loss was recorded in one of these females and stagnation of body weight in the other female from test day 2 to test day 4.
There were no effects on body weight in the remaining female.

Gross pathology:

There were no macroscopic findings.

Other findings:

none

Temperature, relative humidity and oxygen concentration during exposure were considered to be satisfactory for this type of study.

 Data on temperature, relative humidity and oxygen concentration are presented in the following table:

 

Recording Time [hours:min]	Hours after exposure start	O2Concentration [Vol %]	Temperature [°C]	Relative Humidity [% RH]
07:15	0:00	20.6	22.8	4.7
07:45	0:30	20.6	22.9	3.0
08:15	1:00	20.6	22.9	2.5
08:45	1:30	20.4	22.9	2.4
09:15	2:00	20.4	22.9	2.4
09:45	2:30	20.4	22.9	2.4
10:15	3:00	20.4	22.9	2.4
10:45	3:30	20.4	22.9	2.3
11:15	4:00	20.4	22.9	2.3
Mean	Mean	20.5	22.9	2.7
St. Dev.	St. Dev.	0.1	0.0	0.7
N	N	10	10	10

 

 

The nominal aerosol concentration was 22 mg/L air.The chemical aerosol concentration determined was 23 mg/L air as targeted.The aerosol concentration was stable during the exposure period.The nominal vapor concentration was slightly lower than the concentration determined chemically. This small difference was considered to be within the variation of the assay for chemical analysis and accordingly it was concluded that the efficiency was close to 100%.

Data on chemical concentration are presented in the following table:

 

Sampling Time [hours:min]	Sampling Volume [L]	Amount of Test Item in Washbottles [mg]	Chemical Vapor Concentration [mg/L air]
07:30 – 07:35	5.0	106.34 1	22
08:30 – 08:35	5.0	107.740	23
09:30 – 09:35	5.0	108.244	23
10:30 – 10:35	5.0	109.850	23
Mean			23
St. Dev.			0
N			4

 

Interpretation of results:

GHS criteria not met

Conclusions:

In conclusion, the LC0 of Di-tert-butyl Peroxide obtained in this study was estimated to be greater than 22 mg/L air (nominally determined mean aerosol concentration). There was no indication of relevant sex-related differences in toxicity of the test item.

Executive summary:

A group of three male and three female albino rats [RccHan:WIST(SPF)] was exposed by nose-only, flow-past inhalation for four hours to vapours of the test item at a chemically determined concentration of 23 mg/L air.All animals were observed for clinical signs and mortality during the inhalation exposure and theobservation period of 14 days. Body weights were recorded prior to exposure on test day 1, and during the observation period on test days 2, 4, 8 and 15 before necropsy. On day 15 all animals were sacrificed and necropsied.

The ranges of aerosol concentration, temperature, relative humidity, oxygen content and airflow rate measured during the exposure were considered to be satisfactory for a study of this type. In addition, the test item was considered to be respirable to rats. All animals survived the scheduled observation period. Tachypnea and shivering were recorded during exposure until 1 hour after exposure end. Ruffled fur was observed after exposure on test day 1 and test day 2. There were no clinical signs from test day 3 onwards. There were slight effects on body weight from test day 1 to 4. No macroscopic findings were recorded during necropsy.

In conclusion, the LC₀ of di-tert-butyl peroxideobtained in this study was estimated to be greater than 22 mg/L air. There was no indication of relevant sex-related differences in toxicity of the test item.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating conc.

Value:

22 000 mg/m³ air

Quality of whole database:

Klimisch 1 study, GLP compliant.

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: 1a: GLP, OECD 402 Guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, lnc., Portage, Michigan.
- Weight at study initiation:270-294 g (male) / 210-217 g (female)
- Housing: individually, individually in suspended stainless steel cages
- Food and water ad libitum
- Acclimation period: at least five days


ENVIRONMENTAL CONDITIONS
- Temperature: 52-74 °F
- Humidity (%): 52 to 76
- Air changes (per hr): 10-15 cycles/hour
- Photoperiod (hrs dark / hrs light): 12/12

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- % coverage: 10% of the total body surface of the animals
- Type of wrap if used: gauze pad held in contact with the skin by means of anadhesive hypoallergenic aerated semi-occlusive dressing and a restraining bandage

REMOVAL OF TEST SUBSTANCE
After an approximate 24-hour exposure period, the gauze dressing, plastic and elastic wrap were removed and the corners of the test site delineated using a marker. Residual test article was removed using gauze moistened with distilled water.

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2000 mg/kg

Duration of exposure:

24H

Doses:

2000 mg/kg

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
* Clinical signs and mortality twice daily on day 0 and then once daily
* Body weight measured just before administration then on days 0, 7 and 14
* Animals were examined for erythema and edema following patch removal on study day 1 and daily thereafter (days 2-14)
- Necropsy : All limit test animals were euthanized (carbon dioxide inhalation) at study termination (day 14) and necropsied. Body cavities (cranial, thoracic, abdominal and pelvic) were opened and examined. No tissues were retained.


The temperature and relative humidity of the animal room (62-74°F and 52-76%, respectively) exceeded the ranges specified in the protocol (61-73°F and 40-70%, respectively) during this study. These ocurrences are considered to have had no adverse effect on the outcome of this study.

Sex:

male/female

Dose descriptor:

LD0

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality

Clinical signs:

other: The most notable clinical abnormalities observed during the study included urine stain and dark material around the facial area, which occurred during the 24 hour exposure period. Dermal irritation was noted at the site of test article application.

Gross pathology:

No gross pathology was found at necropsy.

Interpretation of results:

GHS criteria not met

Conclusions:

Under these experimental conditions, the dermal LD0 of di-tert-amyl peroxide is more than 2000 mg/kg in rats.

Executive summary:

The acute dermal toxicity of Di-tert-amyl peroxide was evaluated in rats according to a method similar to OECD 402 . The test item was applied to the skin of ten Sprague-Dawley rats (five males and five females) at the dose-level of 2000 mg/kg in semi-occlusive dressing for 24 hours. Animals were then observed during 14 days for mortality, clinical signs, effects on body weight and then necropsied. No mortality occurred during the limit test. The most notable clinical abnormalities observed during the study included urine stain and dark material around the facial area, which occurred during the 24 hour exposure period. Dermal irritation was noted at the site of test article application. Body weight loss was noted for two female rats during the study day 0-7 interval and for one female during the study day 7-14 interval. Body weight gain was noted for all other animals during the test period. No significant gross internal findings were observed at necropsy on study day 14. Under the experimental conditions, the dermal LD0 of the test item Di-tert-amyl peroxide is higher than 2000 mg/kg in male/female rats.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

2 000 mg/kg bw

Quality of whole database:

Klimisch 1 study, GLP compliant.

Justification for classification or non-classification

According to EU Regulation (EC) N0. 1272/2008 (CLP), di-tert amyl peroxide is not classified for acute toxicity.