Reaction mass of tetraalkyl-3,3’-di(propan-2-yl)biphenyldiyl tetrakis(dialkylphenyl) bis(phosphite) and tris(dialkylphenyl) phosphite

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation / corrosion

Remarks:

in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method B.40 (In Vitro Skin Corrosion: Transcutaneous Electrical Resistance Test (TER))

GLP compliance:

no

Test material

Test material information

Constituent 1

Test material form:

solid: crystalline

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

Adult HM:(NZW)fBR New Zealand White rabbits were received from Covance Research
Products, Denver, Pennsylvania. The rabbits were housed singly in stainless steel, wire-mesh
cages suspended above cage boards. Each rabbit was assigned a unique identification number
which was recorded on a card affixed to the cage. The last 3 digits of the identification number
were written on the inside of each rabbit’s ear with a water insoluble marker. The rabbits were
offered approximately 125 grams of PMI® Nutrition International, LLC Certified High Fiber
Rabbit LabDiet® 5325 daily during the study. Water was available ad libitum.
As specified in the Haskell Laboratory animal health and environmental monitoring program, the
following procedures are performed periodically to ensure that contaminant levels are below
those that would be expected to impact the scientific integrity of the study:
• Water samples are analyzed for total bacterial counts, and the presence of coliforms, lead,
and other contaminants.
• Feed samples are analyzed for total bacterial, spore, and fungal counts.
• Samples from freshly washed cages and cage racks are analyzed to ensure adequate sanitation
by the cagewashers.
Certified animal feed is used, guaranteed by the manufacturer to meet specified nutritional
requirements and not to exceed stated maximum concentrations of key contaminants, including
specified heavy metals, aflatoxin, chlorinated hydrocarbons, and organophosphates. The
presence of these contaminants below the maximum concentration stated by the manufacturer
would not be expected to impact the integrity of the study.
The animal health and environmental monitoring program is administered by the attending
laboratory animal veterinarian. Evaluation of these data did not indicate any conditions that
affected the validity of the study.
Rabbits were weighed and observed for general health during the 7-day quarantine period.
Animal rooms were maintained on a timer-controlled, 12-hour light/12-hour dark cycle.
Environmental conditions of the rooms were targeted for a temperature of 20°C ± 1°C and
relative humidity of 50% ± 10%. Excursions outside these ranges were judged to have been of
insufficient magnitude and/or duration to have adversely affected the validity of the study.

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

water

Controls:

other: The adjacent areas of the untreated skin were used for comparison.

Amount / concentration applied:

0.5 g

Duration of treatment / exposure:

4 h

Observation period:

72 h

Number of animals:

6

Details on study design:

Approximately 24 hours prior to treatment, the fur of 6 male New Zealand White rabbits was
closely shaved to expose the skin from the scapular to the lumbar region of the back. The rabbits
weighed from 1775 to 2167 grams on the day of treatment.
The area to be treated (approximately 6 cm²) was marked on each rabbit's back with a waterinsoluble
marker. Approximately 0.5 g of H-25286, moistened with approximately 0.5 mL of
deionized water to form a thick paste, was applied to the test site and covered with a 2-ply,
1-inch square gauze pad. The pad was held in place with non-irritating tape. The trunk of each
rabbit was wrapped with porous tape. The tape was further secured with waterproof tape. The
rabbits were returned to their cages after treatment. Two other test substances were tested
concurrently on a separate, localized test site on the backs of these rabbits.
Approximately 4 hours after application of the test substance, the rabbits were removed from
their cages and the wrappings and gauze pads were removed. The test sites were gently washed
with warm water and Lander® soap to remove excess test substance and gently patted dry. The
rabbits were then returned to their cages.
Approximately 1, 24, 48, and 72 hours after removal of the test substance, the test sites were
evaluated for erythema, edema, and other evidence of dermal effects and were scored according
to the Draize Scale (Table 1). A glossary of dermal effects and abbreviations is presented in
Table 2. The adjacent areas of the untreated skin were used for comparison. The rabbits were
also examined for clinical signs of toxicity at every dermal evaluation. The rabbits were weighed
on the day of treatment and at the last dermal evaluation.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 1 h

Score:

ca. 1.5

Max. score:

4

Reversibility:

no data

Results 2

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 24 h

Score:

ca. 2.2

Max. score:

4

Reversibility:

no data

Results 3

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 48

Score:

ca. 3

Max. score:

4

Reversibility:

no data

Results 4

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 72 h

Score:

ca. 3

Max. score:

4

Reversibility:

no data

Results 5

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 1 - 72 h

Score:

ca. 1

Max. score:

4

Reversibility:

no data

Irritant / corrosive response data:

Although the test substance adhered to the skin of the rabbits throughout the study, the test sites could be evaluated for erythema. The irritation observed may have been made worse by the inability to remove all of the test substance from the animals.
At one hour after washing, no dermal irritation was observed in two rabbits, slight erythema was observed in one rabbit, mild erythema was observed in one rabbit, and moderate erythema and mild edema were observed in two rabbits. At 24 hours, slight erythema was observed in one
rabbit, mild erythema was observed in three rabbits, and moderate erythema was observed in two rabbits. At 48 hours, two rabbits exhibited mild erythema, four exhibited moderate erythema, and three exhibited epidermal scaling. At 72 hours, two rabbits exhibited mild erythema, three
exhibited moderate erythema, and one exhibited severe erythema. Epidermal scaling was observed in four rabbits and hyperkeratosis was observed in one rabbit at 72 hours. One rabbit also exhibited mild edema at 24 and 48 hours and slight edema at 72 hours. No clinical signs
were observed, and no body weight loss occurred during the study.

Applicant's summary and conclusion

Interpretation of results:

irritating

Remarks:

Migrated information Criteria used for interpretation of results: expert judgment

Conclusions:

Under the conditions of this study, H-25286 was a severe skin irritant.
If these test scores are to be used for EEC/OECD classification, according to the guide to the
labeling of dangerous substances published in the Official Journal of European Communities
(67/548/EEC), H-25286 probably should be classified as irritant unless additional data proves
otherwise.