Potassium thiocyanate

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

09 March, 2016 - 10 March, 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study has been performed according to OECD and/or EC guidelines and according to GLP principles.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

(2012)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

(2008)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2400 (Acute Eye Irritation)

Version / remarks:

(1998)

Deviations:

no

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: JMAFF Guidelines (2000), including the most recent revisions.

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Sodium thiocyanate

EC Number:

208-754-4

EC Name:

Sodium thiocyanate

Cas Number:

540-72-7

IUPAC Name:

sodium thiocyanate

Test material form:

solid: crystalline

Details on test material:

- Name of test material (as cited in study report): Sodium thiocyanate
- Appearance: White crystals
- Batch: 1510071519
- Purity/Composition: 99.9%
- Test item storage: At room temperature
- Stable under storage conditions: until 25 November 2018 (retest date)
Certificate of Analysis included in report

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Charles River France, L’Arbresle Cedex, France.
- Age at study initiation: 20 weeks
- Weight at study initiation: 4.315 kg
- Housing: Animals were individually housed in labeled cages with perforated floors
- Diet: Free access to pelleted diet for rabbits (Global Diet 2030 Harlan Teklad®, Italy). Hay and wooden sticks were available during the study period.
- Water: Free access to tap water.
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): set to maintain 18 – 24
- Humidity (%): set to maintain 40 - 70
- Air changes (per hr): at least 10
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Vehicle:

unchanged (no vehicle)

Controls:

other: One eye of each animal remained untreated and served as the reference control.

Amount / concentration applied:

TEST MATERIAL
- ground to a powder using a mortar and pestle prior to weighing.
- Amount applied: 60.7 mg (volume of approximately 0.1 mL)

Duration of treatment / exposure:

Single instillation on Day 1.

Observation period (in vivo):

The eyes of each animal were examined approximately 1 and 24 hours after instillation of the test substance.

Number of animals or in vitro replicates:

1 female

Details on study design:

STUDY DESIGN
The study was performed in a stepwise manner and was started by treatment of a single rabbit (sentinel). Based on the severity of the ocular lesions observed during the study, the animal was sacrificed for ethical reasons immediately after the 24 hours observation and the two further rabbits assigned to the study were not treated.

PREEMPTIVE PAIN MANAGEMENT
One hour prior to instillation of the test substance, buprenorphine (Buprenodale®, Dechra Ltd., Stokeon-Trent, United Kingdom) 0.01 mg/kg bw was administered by subcutaneous injection in order to provide a therapeutic level of systemic analgesia.
Five minutes prior to instillation of the test substance, two drops of the topical anesthetic alcaine 0.5% (SA Alcon-Couvreur NV, Puurs, Belgium) were applied to both eyes.
TREATMENT
The animal was treated by instillation of, 60.7 mg of the test item (a volume of approximately 0.1 mL), in the conjunctival sac of one of the eyes after gently pulling the lower lid away from the eyeball. The lids were then gently held together for about one second to prevent loss of the test item. The other eye remained untreated and served as the reference control.
Immediately after the 24-hour observation, a solution of 2% fluorescein (Merck, Darmstadt, Germany) in water (adjusted to pH 7.0) was instilled into both eyes of each animal to quantitatively determine corneal epithelial damage. Any bright green stained area, indicating epithelial damage, was estimated as a percentage of the total corneal area.
Immediately after fluorescein examination on Day 2, in order to provide a continued level of systemic analgesia, buprenorphine 0.01 mg/kg and meloxicam (Metacam®, Boehringer Vetmed GmbH, Ingelheim/Rhein, Germany) 0.5 mg/kg were administered by subcutaneous injection.
Additional injections were supplied during the observation period to reduce pain and distress After the final observation, the animal was sacrificed by intra-venous injection of Euthasol® 20% (AST Farma BV, Oudewater, The Netherlands).

REMOVAL OF TEST SUBSTANCE
-Washing: No

OBSERVATIONS
- Mortality/Viability: Twice daily.
- Toxicity: At least once daily.
- Body Weight: Day of treatment (prior to instillation) and on day of the final observation.
- Necropsy: No necropsy was performed according to protocol.
- The eyes of the animal were examined approximately 1 and 24 after instillation of the test item. The irritation scores and a description of all other (local) effects were recorded. The irritation was assessed according to OECD 405.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Remarks:

(opacity)

Basis:

animal #1

Time point:

other: 24 hrs.

Score:

2

Max. score:

4

Remarks on result:

other: Animal sacrificed after 24 hrs

Results 2

Irritation parameter:

iris score

Basis:

animal #1

Time point:

other: 24 hrs.

Score:

1

Max. score:

2

Remarks on result:

other: Animal sacrificed after 24 hrs

Results 3

Irritation parameter:

conjunctivae score

Remarks:

(redness)

Basis:

animal #1

Time point:

other: 24 hrs.

Score:

3

Max. score:

3

Remarks on result:

other: Animal sacrificed after 24 hrs

Results 4

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

other: 24 hrs.

Score:

4

Max. score:

4

Remarks on result:

other: Animal sacrificed after 24 hrs

Irritant / corrosive response data:

Instillation of 61 mg of Sodium thiocyanate (a volume of approximately 0.1 mL) into an eye of one rabbit resulted in severe effects ocular effects and signs of discomfort of the animal (tilted head) necessitating the sacrifice the animal for humane reasons at 24 hours after instillation. The signs consisted of grey/white discouloration (sign of necrosis) of the eyelids and nictitating membrane. Moreover, injuries of the cornea and iris were noted. Corneal injury consisted of opacity and epithelial damage. Further, at 24 hours after dosing red discolouration of the lachrymal fluid was noted.

Other effects:

No staining of (peri) ocular tissues by the test substance was observed and no test substance remnants were seen.
No effects on Body weight was shown by the animal.
No further signs of systemic toxicity were observed in the animal during the test period and no mortality occurred.

Applicant's summary and conclusion

Interpretation of results:

Category 1 (irreversible effects on the eye)

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

In an eye irritation study with a male rabbit with Sodium thiocyanate, performed according to OECD 405 test guideline, occular corrosion was observed.

Executive summary:

The acute eye irritation/corrosion of Sodium thiocyanate was determined in accordance with OECD 405 (2012) and according to GLP principles. A single sample of 61 mg (a volume of approximately 0.1 mL) of Sodium thiocyanate was instilled into an eye of one rabbit. Observations were made 1 and 24 hours after instillation.

Instillation of 61 mg of Sodium thiocyanate (a volume of approximately 0.1 mL) into an eye of one rabbit resulted in severe effects ocular effects and signs of discomfort of the animal (tilted head) necessitating the sacrifice the animal for humane reasons at 24 hours after instillation. The signs consisted of grey/white discouloration (sign of necrosis) of the eyelids and nictitating membrane. Moreover, injuries of the cornea and iris were noted. Corneal injury consisted of opacity and epithelial damage. Further, at 24 hours after dosing red discolouration of the lachrymal fluid was noted.

 

Based on the results, Sodium thiocyanate should be classified as Irreversible effects on the eye (Category 1) and labeled as H318: Causes serious eye damage, according to the Regulation (EC) No 1272/2008 on classification, labelling and packaging of substances and mixtures (including all amendments).