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Diss Factsheets

Toxicological information

Acute Toxicity: oral

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Administrative data

acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Apparently well conducted GLP study
Reason / purpose for cross-reference:
reference to other study

Data source

Reference Type:
study report
Report date:

Materials and methods

Test guideline
according to guideline
OECD Guideline 401 (Acute Oral Toxicity)
Principles of method if other than guideline:
Not applicable
GLP compliance:
Test type:
standard acute method
Limit test:

Test material

Constituent 1
Chemical structure
Reference substance name:
Dilauroyl peroxide
EC Number:
EC Name:
Dilauroyl peroxide
Cas Number:
Molecular formula:
dodecanoyl dodecaneperoxoate
Constituent 2
Reference substance name:
Details on test material:
A consignment of 100 g (net) Laurox, white flakes, was received from the Sponsor on 2 October 1992. The test material was further identified by the
Batch No. 0029209020111, the CAS No. 105-74-8 and the EINECS No. 2033263. It was stated to be Dilauroyl peroxlde and was 99.7% pure.

Test animals

Details on test animals or test system and environmental conditions:
Young adult rats of the CD strain (remote Sprague-Dawley origin) were supplied by Charles River (U.K.) Limited, Margate, Kent, England. The animals
were bred under barriered conditions and traveled from the supplier to the animal holding room in sealed boxed with filter protected air-vents. The
albino rat was selected for this study as it has been widely accepted as the standard laboratory species for use in acute toxicity tests.
The strain has been used for toxicological purposes since its establishment under S.P.F. conditions in 1955.

The animals were housed in stainless steel grid cages (Stephen Clark Fabrications Limited, Alva, Clackmannanshire, Scotland). The grid floors
ensured rapid removal of waste material to undertrays which were cleaned out as necessary. Five animals of the same sex were accommodated in
each cage. The cages were suspended in mobile stainless steel racks.

The animals were held in a limited-access facility. All rooms were kept at slight positive pressure relative to the outside and each had its own filtered
air supply giving approximately 15 complete air changes per hour without re-circulation. A temperature range of 18-21°C and a relative humidity
range of 38~57% R.H. were achieved. The small number of low humidity values (below 40%) did not have any overt effect on the well-being of the
animals. Electric time-switches regulated a lighting cycle of 12 hours of artificial light per day. An emergency generator was available to maintain the
electricity supply in the event of a power failure. All personnel entering the building changed into clean protective clothing and wore a gown, gloves,
plastic over-shoes and face mask to service animal-holding areas. A commercially-available complete pelleted rodent diet (RM-l S.Q.C., from Special Diets Services Limited, Witham, Essex, England) was fed without restriction, except for the removal of food for approximately 19 hours before
administration of the test material. The manufacturer supplied analytical data with each batch of diet which included concentrations of nutritional
components, aflatoxins and selected heavy metals, pesticides and micro-organisms. The diet contained no added antibiotic or other
chemotherapeutic or prophylactic treatment.

Animals had free access to tap water taken from the public supply; in England the supply and quality of this water is governed by Department of the
Environment regulations. Certificates of analysis were routinely received from the supplier (Suffolk Water Company). At approximately six-month
intervals water was routinely sampled for analysis, by a laboratory independent of the supplier, for selected chlorinated and organophosphorus
pesticides, polychlorinated biphenyls and lead and cadmium contaminants; it was also examined for coliform bacteria.
Results of these analyses are retained in the archives. There was no known information to indicate that normal levels of common contaminants, or
any specific contaminants, in the diet or drinking water would influence the outcome of the study.

Administration / exposure

Route of administration:
oral: gavage
maize oil
Details on oral exposure:
The test material was prepared at the appropriate concentration in maize oil. The dosage was calculated and expressed gravimetrically in
terms of the material as received. A fresh formulation of the test material was prepared shortly before administration and any surplus remaining after dosing was destroyed on the same day.

Dose-volume was determined for each animal according to the fasted bodyweight on the morning of dosing. Dosing commenced on the morning of
Day 1.
On the basis of of a preliminary study at 800 mg/kg bodyweight in which there were no mortalities, the main study was carried out using a single
group of five male and five female rats given a single oral administration of Laurox at the maximum practicable dosage of 2000 mg/kg (Regulatory
limit test), at a constant volume-dosage of 10 ml/kg in maize oil.

Dose-volume was determined for each animal according to the fasted bodyweight on the morning of dosing. Dosing commenced on the morning of Day 1. A flexible portex catheter (8-choke) was passed down the oesophagus allowing instillation of the dose into the lumen of the stomach. Each
animal was returned to its cage and food hoppers were refilled approximately three hours after dosing.
No. of animals per sex per dose:
Control animals:
Details on study design:
Three separate inspections were made during the first hour after dosing and two further inspections during the remainder of Day 1. From Day 2
onwards, the animals were inspected twice daily (morning and afternoon). The type, time of onset and duration of reactions to treatment were
recorded. The bodyweight of each animal was recorded on the day before dosing and on Days 1, 8 and 15. The test was terminated on the
morning of Day 15.

All animals were killed at termination of the study. Each animal was thoroughly examined for abnormality of tissues or organs. All body cavities were
opened, larger organs were sectioned and the gastro-intestinal tract was opened at intervals for examination of the mucosal surfaces. All
abnormalities were described or the normal appearance of major organs was confirmed. No tissues were retained in fixative.

Results and discussion

Preliminary study:
Not applicable
Effect levels
Dose descriptor:
Effect level:
> 2 000 mg/kg bw
There were no mortalities.
Clinical signs:
other: Signs of reaction were confined to piloerection in all animals on the day of treatment. The animals were overtly normal on the following day.
Gross pathology:
There were no significant macroscopic lesion.
Other findings:

Any other information on results incl. tables


Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
The acute oral LD50 of Laurox to rats was greater than 2000 mg/kg bodyweight.
Executive summary:

The study was conducted to determine the acute oral toxicity of Laurox to rats in accordance with OECD 401. Rats were administered the test article at 2000 mg/kg bodyweight via gavage and observed for 14 days.

There were no mortalities following the oral administration of Laurox at 2000 mg/kg bodyweight. Piloerection was noted in all animals on the day of dosing. There were no significant necropsy findings.