Registration Dossier

In an early US guideline study, ammonium hexachloroplatinate (0.5 g) was applied (24-hr, occluded) to the shaved abraded and intact skin of six rabbits. Slight but reversible indications of irritation to intact skin were observed in three animals during the observation period (Middleton, 1978b).

In a guideline study, to GLP, instillation of ammonium hexachloroplatinate (0.1 ml) into one eye of each of three rabbits caused severe irritation and corrosion (Berthold, 1994).

No relevant respiratory tract irritation data were identified.

Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

No data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study apparently performed according to the method described in Federal Register 1973, Vol. 38, No. 187, Section 1500: 41, which has some significant deviations from current OECD guidelines.

Remarks:

Certain of these deviations are likely to increase the possibility of an irritant reaction.

Qualifier:

according to guideline

Guideline:

other: Skin irritation patch test, as described in Federal Register 1973, Vol. 38, No. 187, Section 1500: 41.

Deviations:

not specified

Principles of method if other than guideline:

0.5 g of material was applied on a gauze pad to abraded and non-abraded skin of six albino rabbits. The site was covered with adhesive tape. The sites were examined after 24 and 72 hours for erythema and oedema.

GLP compliance:

not specified

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: “recognised breeders”
- Age at study initiation: 16-18 weeks
- Weight at study initiation: 2.3 kg (average)
- Diet: ad libitum commercial rabbit diet from Rank Hovis MacDougal
- Water: ad libitum

ENVIRONMENTAL CONDITIONS
- Photoperiod (hrs dark / hrs light): “Natural lighting conditions”

Type of coverage:

occlusive

Preparation of test site:

other: Backs of the rabbits were shaved (not “closely clipped” as recommended by the OECD guidelines). One site of each rabbit was abraded immediately before application of the test material, the other site remained intact.

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 g

Duration of treatment / exposure:

24 hrs

Observation period:

48 hrs

Number of animals:

Six females

Details on study design:

TEST SITE
- Area of exposure: Each site 2.5 cm2 (one intact, one abraded)
- Type of wrap if used: Gauze pad was secured by “Sleek” tape (evidently a waterproof tape)

REMOVAL OF TEST SUBSTANCE
- Washing (if done): None

SCORING SYSTEM: Erythema (and eschar) formation and oedema formation were assessed on the intact and abraded skin of six rabbits at 24 and 72 hrs after initial application of the test compound (i.e. as soon as the dressing was removed and again 48 hrs later). The primary irritation index was calculated by adding the four values for erythema (and eschar) formation to the four for oedema formation, and dividing the total by four. According to the study report, Draize (1959) considers that “compounds producing combined averages (primary irritation indices) of 2 or less are only mildly irritating; whereas those with indices of 2 to 5 are moderate irritants, and those with scores above 6 are considered severe irritants”.

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Time point:

other: 24 and 72 hrs after initial application

Score:

1.3

Max. score:

8

Reversibility:

other: Reversibility not assessed, as observation period only 48 hrs (not up to 14 days as recommended in the OECD guidelines)

Other effects:

“Two abraded sites showed evidence of changes, possibly necrosis, associated with the abrasions in the skin”. The systemic toxicity was not reported.

Table: Individual animal scores for each time point

Animal number	Time/hr	Erythema		Oedema
		Abraded skin	Intact skin	Abraded skin	Intact skin
1	24	1	0	0	0
	72	2	0	1	0
2	24	0	0	0	0
	72	0	0	0	0
3	24	1	0	1	0
	72	1	0	0	0
4	24	2	2	2	1
	72	N2	1	1	0
5	24	N2	1	2	1
	72	N2	0	1	0
6	24	1	1	0	0
	72	0	0	0	0

N: Necrosis associated with abrasions

Interpretation of results:

slightly irritating

Remarks:

Migrated information not irritant by EU criteria Criteria used for interpretation of results: other: Classified “according to the US Federal Register 1973 skin test”

Conclusions:

In an early US guideline study, ammonium hexachloroplatinate (0.5 g) was applied (24-hr, occluded) to the shaved abraded and intact skin of six rabbits. Slight but reversible indications of irritation to intact skin were observed in three animals during the observation period.

Executive summary:

In a US Federal Register Patch Test (1973), the skin irritant potential of ammonium hexachloroplatinate was assessed in six female New Zealand White rabbits. The test material (0.5 g) was applied (occluded) to the shaved abraded and intact skin for 24 hr.The sites were assessedfor evidence of erythema (and eschar) formation and oedema formation immediately upon removal of the patch, and again 48 hr later.

Three intact skin sites showed evidence of erythema/oedema which was observed to be reversible (or showed indications of reversibility) during the observation period. No signs of irritation were apparent on the other three intact sites. Two abraded skin sites showed evidence of possible necrosis associated with the abrasions in the skin.A Primary Irritation Score of 1.3 (out of 8) was obtained. The study authors classified ammonium hexachloroplatinate as a mild skin irritant in this test system.

This study suffered from a number of significant deviations from those given in the current OECD guidelines, including use of abraded skin, no moistening of test substance (a powder) to ensure good skin contact, a longer exposure period and failure to wash off any residual test material after removal of patch, observation period was insufficient to assess reversibility of effects, and skin was only examined on 2 occasions, at 0 and 48 hrs, rather than at 1, 24, 48 and 72 hrs, after patch removal. However, certain of these deviations are likely to increase the possibility of an irritant reaction, so the study can be considered as likely more sensitive than the current methodology to identify potential irritants.

Based on the results of this study, no classification for skin irritation is required under EU CLP criteria (EC 1272/2008).

Endpoint conclusion:

adverse effect observed (irritating)

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

20 Dec 1993 - 10 Jan 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study carried out in accordance with OECD and EU guidelines

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

other: White Russian (albino)

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Breeder: ASTA Medica AG, D-33790, Halle/Westfalen
- Age at study initiation: Male 14 months; females 15 months
- Weight at study initiation: Male 2.31 kg; females 2.35 and 3.18 kg
- Housing: Stainless steel cages with grating floor, one animal/cage
- Diet (e.g. ad libitum): Approx. 120 g/day standard diet (“ssniff K”)
- Water (e.g. ad libitum): Ad libitum
- Acclimation period: At least one day

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18.5-20
- Humidity (%): 58-70
- Photoperiod (hrs dark / hrs light): 12 hrs dark / 12 hrs artificial light

Vehicle:

unchanged (no vehicle)

Controls:

other: second eye of treated animals served as concurrent control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 89.1-94.4 mg (volume of about 0.1 ml)

Duration of treatment / exposure:

Eyelids were briefly closed by gentle finger pressure, no subsequent washing to remove test substance.

Observation period (in vivo):

1, 24, 48 and 72 hours after application, thereafter once daily. 2 animals were observed for 7 days after application, then killed because of the severe effects observed. The remaining animal was observed for 21 days.

Number of animals or in vitro replicates:

3 (1 male, 2 females)

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done): the treated eye was not rinsed

SCORING SYSTEM: Signs of irritation on the cornea, iris and conjunctiva were assessed quantitatively and qualitatively using the Draize scale (see attachment 3 for details) assessed at 1, 24, 48, and 72 hrs (and daily thereafter) following application of the test material into the eye.

TOOL USED TO ASSESS SCORE: Cliptrix pencil light

Irritation parameter:

other: An irritation index could not be determined because of the corrosive effects.

Reversibility:

not fully reversible within: 7 days in two of the animals

Remarks on result:

positive indication of irritation

Remarks:

An irritation index could not be determined because of the corrosive effects

Irritant / corrosive response data:

Corrosive effects seen in the treated eyes of two rabbits, marked (but reversible) irritation in the third (see Tables 1a and 1b for details).

Other effects:

The only systemic effects observed were a very slight loss of body weight detected in the two animals showing corrosive eye damage.

Interpretation of results:

Category I

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

In a guideline study, to GLP, instillation of ammonium hexachloroplatinate (0.1 ml) into one eye of each of three rabbits caused severe irritation and corrosion.

Executive summary:

In an in vivo eye irritation study carried out in accordance with OECD Test Guideline 405, and to GLP, a 0.1 ml aliquot of undiluted ammonium hexachloroplatinate was instilled into the conjunctival sac of the right eye of three White Russian rabbits (one male, two females). The left eye was untreated to serve as a control. Following instillation the eyelids were held closed by gentle finger pressure. The ocular response was assessed at 1, 24, 48 and 72 hours and thereafter once daily for up to 21 days. Corneal opacity, effects on the iris and conjunctival redness, chemosis and discharge were scored according to the Draize numerical scale. Any clinical signs of toxicity were noted and body weights were also recorded. The treated eye as well as eye lids and nictitating membrane were assessed microscopically.

A number of severe (and often irreversible) effects were observed, including opacity and necrosis of the cornea, moderate circumcorneal hyperaemia of the iris, diffuse redness of the conjunctiva, swelling of the eyelids, as well as ocular discharge and the formation of a white mucus over the eyes. Two animals were killed 7 days after application because of the severe effects observed. The histopathological examination revealed a pronounced irritation potential of the test material, leading to very severe coagulation necrosis after conjunctival application. An irritation index could not be determined because of the corrosive effects. No systemic toxicity was observed other than a very slight reduction in body weight in the two rabbits showing corrosive effects.

Based on the results of this study, the test material should be classified for serious eye damage (Category 1) according to EU CLP criteria (EC 1272/2008).

Endpoint conclusion:

adverse effect observed (irreversible damage)

Endpoint conclusion:

no study available

No relevant human irritation/corrosion data were identified. No in vitro skin or eye irritation studies were identified, or are required, as reliable in vivo studies are already available.

In a US Federal Register Patch Test (1973), the skin irritant potential of ammonium hexachloroplatinate was assessed in six female New Zealand White rabbits. The test material (0.5 g) was applied (occluded) to the shaved abraded and intact skin for 24 hr. The sites were assessed for evidence of erythema (and eschar) formation and oedema formation immediately upon removal of the patch, and again 48 hr later. Three intact skin sites showed evidence of erythema/oedema which was observed to be reversible (or showed indications of reversibility) during the observation period. No signs of irritation were apparent on the other three intact sites. Two abraded skin sites showed evidence of possible necrosis associated with the abrasions in the skin. A Primary Irritation Score of 1.3 (out of 8) was obtained. The study authors classified ammonium hexachloroplatinate as a mild skin irritant in this test system (Middleton, 1978b). This study suffered from a number of significant deviations from those given in the current OECD guidelines, including use of abraded skin, no moistening of test substance (a powder) to ensure good skin contact, a longer exposure period and failure to wash off any residual test material after removal of patch, observation period was insufficient to assess reversibility of effects, and skin was only examined on 2 occasions, at 0 and 48 hr, rather than at 1, 24, 48 and 72 hr, after patch removal. However, certain of these deviations are likely to increase the possibility of an irritant reaction, so the study can be considered as likely more sensitive than the current methodology to identify potential irritants.

In an in vivo eye irritation study carried out in accordance with OECD Test Guideline 405, and to GLP, a 0.1 ml aliquot of undiluted ammonium hexachloroplatinate was instilled into the conjunctival sac of the right eye of three White Russian rabbits (one male, two females). The left eye was untreated to serve as a control. Following instillation the eyelids were held closed by gentle finger pressure. The ocular response was assessed at 1, 24, 48 and 72 hours and thereafter once daily for up to 21 days. Corneal opacity, effects on the iris and conjunctival redness, chemosis and discharge were scored according to the Draize numerical scale. Any clinical signs of toxicity were noted and body weights were also recorded. The treated eye as well as eye lids and nictitating membrane were assessed microscopically. A number of severe (and often irreversible) effects were observed, including opacity and necrosis of the cornea, moderate circumcorneal hyperaemia of the iris, diffuse redness of the conjunctiva, swelling of the eyelids, as well as ocular discharge and the formation of a white mucus over the eyes. Two animals were killed 7 days after application because of the severe effects observed. The histopathological examination revealed a pronounced irritation potential of the test material, leading to very severe coagulation necrosis after conjunctival application. An irritation index could not be determined because of the corrosive effects. No systemic toxicity was observed other than a very slight reduction in body weight in the two rabbits showing corrosive effects (Berthold, 1994).

No respiratory tract irritation data were identified. A new study was not conducted as it is not a REACH Standard Information Requirement.

Based on the results of the available and reliable skin and eye irritation studies in rabbits, diammonium hexachloroplatinate does not warrant classification for skin irritation, but should be classified for serious eye damage (category 1) under EU CLP criteria (EC 1272/2008).