Chromium trichloride

Endpoint summary

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study without deviations

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2500 (Acute Dermal Irritation)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

Test species / strain / quality: Rabbits / New Zealand white A 1077 INRA (SPF)
Reasons for the selection of the test species: This animal species is the worldwide accepted test system for skin irritation / corrosion studies.
Age on day 0: Ca. 5 months
Sex: Females
Supplier: Charles River Wiga GmbH, Sandhofer Weg 7, 97633 Sulzfeld, Germany
Arrival in the testing facility: Acclimatization for at least 5 days before application
Identification: Ear tattoo (by the rabbit supplier) and cage cards.
Body weight range on day 0: 3.76 kg - 4.61 kg
Room temperature / relative humidity: The animals were housed in fully air-conditioned rooms. Central air-conditioning guaranteed a range of 20 °C ± 3 °C for temperature and of 30 - 70% for relative humidity. There were no deviations from these ranges, which influenced the results of the study.
Day / night rhythm: 12 h 112 h (6.00 a.m. - 6.00 p.m./6.00 p.m. - 6.00 a.m.)
Type of cage: Stainless steel wire mesh cages with grating with shallow cage body; floor area: 4225 cm2
Enrichment: Wooden gnawing blocks (Typ KNH E-041)
Number of animals per cage: Single housing
Feeding: STANRAB (P) sac; SOS Special Diets Services, 67122 Altrip, Germany
Drinking water: Tap water ad libitum
Tap water ad libitum
Selection of animlas: Before the beginning of application, the application area was investigated for signs of pre-existing skin irritation or dense patches of hair. Only animals with intact healthy skin were used.

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

water

Controls:

other: untreated skin site of the same animal

Amount / concentration applied:

0.5 g, minimally moistened

Duration of treatment / exposure:

4 hours

Observation period:

72 hours and 14 days recovery period

Number of animals:

3

Details on study design:

Clipping of the fur: At least 24 hours before application clipping of the dorsolateral part of the trunk of the animal(s).
Body weight determination: Just before application of the test item and after the last reading.
Route of application: The test item was applied in a single dose to the intact untreated skin. The test patch was secured in position with a semi occlusive" dressing. The test item was removed at the end of the exposure period with Polyethylenglycol and Polyethylenglycol / water (1 : 1).
Application volume: The test patch (2.5 cm x 2.5 cm) was covered with an amount of minimally moistened solid preparation corresponding to a dose of 0.5 g of undiluted test item.
Application site: Flanc
Negative control: Untreated skin sites of the same animal.
Readings: Immediately after removal of the patch, approx. 1, 24, 48 and 72 h after removal of the patch and then in weekly intervals maximally up to day 14. For details about the observation period of each animal see Table: Individual cutaneous observations and mean values in the Appendix.
Illumination used for reading: Daylight tubes "Lumilux" (L 58W/860 PLUS ECO 25X1, Osram, Germany)
Mortality: A check for any dead or moribund animal was made at least once each workday.
The evaluation of skin reactions was performed according to the quoted guidelines.
Erythema and eschar formation
Grading: 0 No erythema, 1 Very slight erythema (barely perceptible), 2 Well defined erythema, 3 Moderate to severe erythema, 4 Severe erythema (beet redness) to eschar formation preventing grading of erythema
Edema formation
Grading: 0 No edema, 1 Very slight edema (barely perceptible), 2 Slight edema (edges of area well defined by definite raising), 3 Moderate edema (raised approx. 1 mm), 4 Severe edema (raised more than 1 mm and extending beyond area of exposure)
Descriptions of any dermal findings not covered by this scale were recorded.

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 1 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 24 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 48 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 1 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 24 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 48 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Irritant / corrosive response data:

No cutaneous reactions were observed during the study. Mean scores over 24, 48 and 72 hours for each animal were 0.0, 0.0 and 0.0 for erythema and 0.0, 0.0 and 0.0 for edema.

Other effects:

none observed

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Chromium trichloride does not show a skin irritation potential to rabbits under the test conditions chosen.

Executive summary:

The potential of Chromium trichloride to cause acute dermal irritation or corrosion was assessed by a single topical application of an amount of 0.5 g of the test item for 4 hours to the intact skin of three White New Zealand rabbits, using a patch of 2.5 cm x 2.5 cm, covered with semi occlusive dressing. After removal of the patch the application area was washed off. The cutaneous reactions were assessed immediately after removal of the patch, approximately 1, 24, 48 and 72 hours after removal of the patch.

No erythema or edema was observed in all animals during the course of the study. Mean scores over 24, 48 and 72 hours for each animal were 0.0, 0.0 and 0.0 for erythema and 0.0, 0.0 and 0.0 for edema. Considering the described cutaneous reactions as well as the average score for irritation, Chromium trichloride does not show a skin irritation potential under the test conditions chosen.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study without deviations

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

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2400 (Acute Eye Irritation)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

Test species / strain / quality: Rabbits / New Zealand white A 1077 INRA (SPF)
Reasons for the selection of the test species: This animal species is the worldwide accepted test system forskin irritation / corrosion studies.
Age on day 0: Ca. 5-6 months
Sex: Males and females
Supplier: Charles River Wiga GmbH, Sandhofer Weg 7, 97633 Sulzfeld, Germany
Arrival in the testing facility: Acclimatization for at least 5 days before application
Identification: Ear tattoo (by the rabbit supplier) and cage cards.
Body weight range on day 0: 4.41 kg - 5.38 kg
HOUSING AND DIET
Room temperature / relative humidity: The animals were housed in fully air-conditioned rooms. Central air-conditioning guaranteed a range of 20 °C ± 3 °C for temperature and of 30 - 70% for relative humidity. There were no deviations from these ranges, which influenced the results of the study.
Day / night rhythm: 12 h / 12 h (6.00 a.m. - 6.00 p.m. / 6.00 p.m. - 6.00 a.m.)
Type of cage: Stainless steel wire mesh cages with grating with shallow cage body; floor area: 4225 cm²
Enrichment: Wooden gnawing blocks (Typ KNH E-041); Abedd(R) Lab. And Vet. Service GmbH Vienna, Austria
Number of animals per cage: Single housing
Feeding: STANRAB (P) SQC; SOS Special Diets Services, 67122 Altrip, Germany
Drinking water: Tap water ad libitum
Selection: Before the beginning of application both eyes were investigated for signs of pre-existing irritation. Only animals with intact cornea and conjunctiva were used.
Analysis of feed: The feed used in the study was assayed for chemical and microbial contaminants by the manufacturer in quarterly intervals.
Analysis of drinking water: The drinking water was regularly assayed for contaminants by the municipal authorities of Heidelberg. The German Drinking Water Regulation of Dec. 5, 1990 served as the guideline for maximum tolerable contaminants.
Bedding and enrichment analysis: The bedding and enrichment were regularly assayed for contaminants (chlorinated hydrocarbons and heavy metals).

Vehicle:

unchanged (no vehicle)

Controls:

other: untreated left eye served as control

Amount / concentration applied:

0.1 mL bulk volume (about 41 mg of the comminuted test item)

Duration of treatment / exposure:

24 hours

Observation period (in vivo):

Readings were made approx. 1, 24, 48 and 72 h after application and then in weekly intervals maximally up to day 28.

Number of animals or in vitro replicates:

3

Details on study design:

EXPERIMENTAL PROCEDURE
Conduct of the study
Body weight determination: Just before application of the test item and after the last reading.
Route of application: The test item was applied in a single dose to the conjunctival sac of the right eyelid.
Application volume: 0.1 mL bulk volume (about 41 mg of the comminuted test item)
Rinsing of the eye: About 24 hours after application of the test item the treated eye of the animal(s) was rinsed with 3 to 6 mL of hand warm tap water for 1 to 2 minutes using a syringe with a blunt probe.
Negative control: Untreated left eye
Readings: Approx. 1, 24, 48 and 72 h after application and then in weekly intervals maximally up to day 28. For details about the observation period of each animal see Table: Individual ocular observations and mean values in the Appendix.
Illumination used for reading: Reactions on cornea or iris were observed by using a slit lamp.
Mortality: A check for any dead or moribund animal was made at least once each workday.
Assessment of ocular reactions
The evaluation of eye irritation was performed according to the quoted guidelines. In addition to specific observations recommended by the regulatory authorities, evaluations were made of discharge from the eye and the area of cornea affected by the lesions.
Cornea opacity (op):
Degree of density (the most dense area is taken for reading)
Grading
0 No ulceration or opacity
1 Scattered or diffuse areas of opacity (other than slight dulling of normal lustre), details of iris clearly visible
2 Easily discernible translucent area, details of iris slightly obscured
3 Nacreous area, no details of iris visible, size of pupil barely discernible
4 Opaque cornea, iris not discernible through the opacity
Iris:
Grading
0 Normal
1 Markedly deepened rugae, congestion, swelling, moderate circumcorneal hyperaemia or injection, any of these observations or combination of any thereof, iris still reacting to light (sluggish reaction is positive)
2 No reaction to light, haemorrhage, gross destruction (any or all of these)
Conjunctivae redness (red) (Refers to palpebral and bulbar conjunctivae, not to cornea and iris):
Grading
0 Blood vessels normal
1 Some blood vessels definitely hyperemic (injected)
2 Diffuse, crimson color, individual vessels not easily discernible
3 Diffuse beefy red
Chemosis (sw) Lids and/or nictitating membrane:
Grading
0 No swelling
1 Any swelling above normal (includes nictitating membrane)
2 Obvious swelling with partial eversion of lids
3 Swelling with lids about half closed
4 Swelling with lids more than half closed
EVALUATION OF RESULTS
For evaluation, the calculation of the mean values of corneal opacity, iris, conjunctival redness and chemosis for readings 24, 48 and 72 hours were quoted. Additionally, the reversibility of the observed findings was taken into account.
The evaluation is based on the criteria of the OECD Harmonized Integrated Classification System that was in place on the date of report signature. Calculations were performed using Microsoft Excel 2003 and checked with a calculator.

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

of 3 animals

Time point:

other: 24 h

Score:

0

Max. score:

4

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

of 3 animals

Time point:

other: 48 h

Score:

0

Max. score:

4

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

of 3 animals

Time point:

other: 72 h

Score:

0

Max. score:

4

Irritation parameter:

iris score

Basis:

mean

Remarks:

of 3 animals

Time point:

other: 24 h

Score:

0

Max. score:

2

Irritation parameter:

iris score

Basis:

mean

Remarks:

of 3 animals

Time point:

other: 48 h

Score:

0

Max. score:

2

Irritation parameter:

iris score

Basis:

mean

Remarks:

of 3 animals

Time point:

other: 72 h

Score:

0

Max. score:

2

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

mean

Remarks:

of 3 animals

Time point:

other: 24 h

Score:

0.33

Max. score:

3

Reversibility:

fully reversible within: 48 hours

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

mean

Remarks:

of 3 animals

Time point:

other: 48 h

Score:

0

Max. score:

3

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

mean

Remarks:

of 3 animals

Time point:

other: 72 h

Score:

0

Max. score:

3

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

of 3 animals

Time point:

other: 24 h

Score:

0

Max. score:

4

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

of 3 animals

Time point:

other: 48 h

Score:

0

Max. score:

4

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

of 3 animals

Time point:

other: 72 h

Score:

0

Max. score:

4

Irritant / corrosive response data:

Slight conjunctival redness (grade 1) was observed in two animals 1 hour after application and persisted in one animal up 24 hours. Slight discharge of the conjunctiva (grade 1) was noted in all animals 1 hour after application. The ocular reactions were reversible in two animals within 24 hours and in one animal within 48 hours after application.
Mean scores calculated for each animal over 24,48 and 72 hours were 0.0, 0.0 and 0.0 for corneal opacity, 0.0, 0.0 and 0.0 for iris lesions, 0.0, 0.0 and 0.3 for redness of the conjunctiva and 0.0, 0.0 and 0.0 for chemosis.

Other effects:

Additional finding of vascularization of the cornea (scleral vessels injected in a circumscribed area) were noted in two animals 1 hour after application.

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Considering the described ocular reactions as well as the average score for irritation, chromium trichloride does not show an eye irritation under the test conditions chosen.

Executive summary:

The potential of chromium trichloride to cause damage to the conjunctiva, iris or cornea was assessed by a single ocular application of 0.1 mL bulk volume (about 41 mg) of the test item to one eye of three White New Zealand rabbits (stepwise procedure starting with one animal and supplementing two additional animals). About 24 hours after application the eye was rinsed with tap water.

The ocular reactions were assessed approximately 1, 24, 48 and 72 hours after application.

Slight conjunctival redness and slight discharge were observed in the animals during the course of the study. Additional findings like vascularization of the cornea in a circumscribed area were noted in the animals during the observation period.

The ocular reactions were reversible in all animals within 48 hours after application.

Mean scores calculated for each animal over 24,48 and 72 hours were 0.0, 0.0 and 0.0 for corneal opacity, 0.0, 0.0 and 0.0 for iris lesions, 0.0, 0.0 and 0.3 for redness of the conjunctiva and 0.0, 0.0 and 0.0 for chemosis.

Considering the described ocular reactions as well as the average score for irritation, Chromium trichloride does not show an eye irritation potential under the test conditions chosen.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin irritation / corrosion

Two studies assessing skin irritation /corrosion potential of chromium trichloride (anhydrous) are available, an in vitro EPIDERM study by Wareing (2010) and an in vivo study by Cords (2010), selected as key study, both showing consistently that chromium trichloride is not a skin irritant. In both studies, the test substance was moistened with water for application.

Wareing 2010 concluded that chromium trichloride does not show a skin irritation potential in the EpiDerm™ skin corrosion/irritation test under the test conditions chosen.

The potential of Chromium trichloride to cause dermal corrosion/irritation was assessed by a single topical application of 25 µL bulk volume (about 25 mg) of the test substance to a reconstructed three dimensional human epidermis model (EpiDerm™) by Wareing 2010.

The EpiDerm™ skin corrosivity/irritation test showed that neither in the corrosion test nor in the irritation test viability of skin tissue was negatively affected.

Based on the observed results and applying the evaluation criteria it was concluded, that chromium trichloride does not show a skin irritation potential in the EpiDerm™ skin corrosion/irritation test under the test conditions chosen.

Cords 2010 investigated the potential of Chromium trichloride (anhydrous) to cause acute dermal irritation or corrosion by a single topical application of an amount of 0.5 g of the test item for 4 hours to the intact skin of three White New Zealand rabbits with semi occlusive dressing. After removal of the patch the application area was washed off. The cutaneous reactions were assessed immediately after removal of the patch, approximately 1, 24, 48 and 72 hours after removal of the patch.

No erythema or edema was observed in all animals during the course of the study. Mean scores over 24, 48 and 72 hours for each animal were 0.0, 0.0 and 0.0 for erythema and 0.0, 0.0 and 0.0 for edema. Considering the described cutaneous reactions as well as the average score for irritation, Chromium trichloride does not show a skin irritation potential under the test conditions chosen.

A surrogate substance, Chromium(3+) tri(pyridine-3-carboxylate) (NBS), also a water soluble chromium(III) compound which is better absorbed than chromium trichloride due to organic complexation, was tested for skin irritation by Shara et al. 2005. In a skin irritation test with New Zealand White rabbits according to OECD 404 with semiocclusive exposure of a 70% w/w mixture on NBS in cornoil, only slight irritation (erythema) were observed during the first 24 hours. No edema were noted. At 48 hours neither erythema nor edema were noted. Thus, the substance NBC was slightly irritating according to US OPPTS 870.2500 and according to EU CLP Regulation considered non-irritant.

Similarly, Thyssen in 1979 assessed chromium hydroxide sulfate, also a soluble chromium(III) compound, by applying 500 mg of the test material under semi-occlusive conditions to the interior surface of the ears of two New Zealand White rabbits. Residual test material was removed after 24 hours by washing with soap and water; animals were observed for 7 days. Scores for irritation were not reported, but it is stated in the report that the test material was not a skin irritant under the conditions of the study. The study protocol is not standard, however it can be concluded that the substance is not a skin irritant.

In conclusion, chromium trichloride was shown being non-irritant to skin in vitro and in vivo which is supported by two studies of other water soluble chromium(III) compounds showing also that neither Chromium(3+) tri(pyridine-3-carboxylate) (NBS) nor chromium hydroxyl sulphate is irritant to skin.

Eye irritation / damage

Two studies assessing eye irritation/damage potential of chromium trichloride (anhydrous) are available, an in vitro HET-CAM study by Wareing (2010) and an in vivo study by Cords (2010), selected as key study, both showing consistently that chromium trichloride is not an eye irritant.

Wareing (2010) assessed the potential of chromium trichloride to cause serious damage to the eyes/mucous membranes by a single topical application of 25 µL bulk volume (about 25 mg) of the undiluted test substance to the chorioallantoic membrane (CAM) of fertilized and incubated hen eggs.

Three eggs were observed for 100 seconds and then the test substance was removed by washing. The occurrence of vascular injury or intravascular coagulation in response to the test substance was recorded. The chorioallantoic membrane of the eggs did not show any irritation effects.

Based on the results of this study and applying the evaluation criteria it is concluded, that chromium trichloride does not produce changes indicative for serious eye damage in the HET-CAM Test under the test conditions chosen.

To further assess eye irritation potential of chromium trichloride in vivo, Cords (2010) investigated the potential of chromium trichloride to cause damage to the conjunctiva, iris or cornea by a single ocular application of 0.1 mL bulk volume (about 41 mg) of the test item to one eye of three White New Zealand rabbits. About 24 hours after application the eye was rinsed with tap water.

The ocular reactions were assessed approximately 1, 24, 48 and 72 hours after application.

Slight conjunctival redness and slight discharge were observed in the animals during the course of the study. Additional findings like vascularization of the cornea in a circumscribed area were noted in the animals during the observation period.

The ocular reactions were reversible in all animals within 48 hours after application.

Mean scores calculated for each animal over 24,48 and 72 hours were 0.0, 0.0 and 0.0 for corneal opacity, 0.0, 0.0 and 0.0 for iris lesions, 0.0, 0.0 and 0.3 for redness of the conjunctiva and 0.0, 0.0 and 0.0 for chemosis.

Considering the described ocular reactions as well as the average score for irritation, Chromium trichloride does not show an eye irritation potential under the test conditions chosen.

The negative findings in vivo and in vitro are supported by two further in vivo studies using surrogate chromium(III) substances.

In an OECD405 eye irritation study (Shara et al. 2005) no irritation response regards corneal activity, iritis, or conjunctivitis (redness and chemosis) was observed at the 24, 48 and 72 hours readings following exposure to Chromium(3+) tri(pyridine-3-carboxylate) (NBS), also a water soluble chromium(III) compound. Only 1 hour following installation of the material NBC conjunctivitis was observed in all animals which was reversible within 24 hours. There were no other signs of gross toxicity, adverse pharmacologic effects or abnormal behaviour.

Similarly, Thyssen (1979) instilled 50 mg of the test material into one eye of two New Zealand White rabbits; ocular reactions were observed for 7 days. Scores for eye irritation are not reported, however the test material was not irritating to the rabbit eye under the conditions of this study.

As a result, the substance chromium trichloride is considered not an eye irritant according to EU CLP (Regulation EC No 1272/2008).

Justification for classification or non-classification

Based on in vitro and in vivo studies, the substance chromium trichloride is considered not an eye or skin irritant according to EU CLP (Regulation EC No 1272/2008) or DSD (Directive 67/548/EEC).