Hafnium tetrachloride

Endpoint summary

Description of key information

With a pH of 1.4 and an acid reserve around 24% HCl equivalent, it was decided to confirm the corrosive properties of HfCl4 with a in vitro Corrositex test to allow the subcategorization of the corrosive class. This test confirmed the category 1B for corrosivity. Tests for irritation to the respiratory tract are not relevant and not done for animal welfare considerations.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study performed according to the current OECD 435 guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 435 (In Vitro Membrane Barrier Test Method for Skin Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Duration of treatment / exposure:

from 0 to 240 minutes

Irritation / corrosion parameter:

other: other: mean breakthrough time

Remarks on result:

other:

Remarks:

Remarks: fields not applicable for Corrositex test. (migrated information)

Irritant / corrosive response data:

mean breakthrough time: 7 minutes and 10 seconds

Qualification screen: the test item produced an immediate colour change and therefore qualified for use in the CORROSITEX assay.

results:

	Test Item Breakthrough Time
	Vial 1	Vial 2	Vial 3	Vial 4
Start Time (hr:min:sec)	00:02:00	00:06:00	00:07:00	00:08:00
Detection Time (hr:min:sec)	00:08:40	00:13:20	00:14:40	00:15:00
Breakthrough Time (hr:min:sec)	00:06:40	00:07:20	00:07:40	00:07:00

hr=    hour(s)

min =  minute(s)

sec =  second(s)

Mean Breakthrough time of the four test item replicates:      7 minutes 10 seconds

CORROSITEX CLASSIFICATION:                    CORROSIVE PACKING GROUP II.

The results of the assay were accepted on condition of adherence to the positive and negative control item ranges given in the following table:

	Chemical	Concentration (weight %)	Breakthrough Time (hr:min:sec)
Positive Control	Sulphuric Acid	95 – 98	00:00:50
Negative Control	Citric Acid	10	No breakthrough observed

Interpretation of results:

corrosive

Remarks:

Migrated information Criteria used for interpretation of results: OECD GHS

Executive summary:

The test item was assessed for its corrosivity potential using the CORROSITEX assay. The method was designed to be compatible with the following: OECD Guidelines for the Testing of Chemicals No. 435 “In VitroMembrane Barrier Test Method for Skin Corrosion” (adopted 19 July 2006).

The assay consisted of:

- a qualification screen with the Chemical Detection System

- a categorisation screen to identify test items as having either a high or low acid/alkaline reserve

- a definitive CORROSITEX assay

Results:

Sample qualified:  YES / Sample category:  1

Mean Breakthrough time  :  7 minutes 10 seconds

Conclusion: The test item was considered to be CORROSIVE and can be assigned the UN Packing Group Criteria II.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (corrosive)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation

Data waiving:

other justification

Justification for data waiving:

other:

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Additional information

Justification for selection of skin irritation / corrosion endpoint:
With a pH of 1.4 and an acid reserve around 24% HCl equivalent, it was decided to confirm the corrosive properties of HfCl4 with a in vitro Corrositex test to allow the subcategorization of the corrosive class. This test confirmed the category 1B for corrosivity.

Justification for selection of eye irritation endpoint:
With a pH of 1.4 and an acid reserve around 24% HCl equivalent, it was decided to confirm the corrosive properties of HfCl4 with a in vitro Corrositex test to allow the subcategorization of the corrosive class. This test confirmed the category 1B for corrosivity.

Effects on skin irritation/corrosion: highly corrosive

Effects on eye irritation: highly corrosive

Effects on respiratory irritation: highly irritating

Justification for classification or non-classification

Hafnium tetrachloride releases hydrogen chloride in contact with water leading to a pH<2, with an acid reserve of 24% HCl equivalent (see section 4.2). The substance is therefore considered corrosive, on the criteria basis of the CLP regulation.

It is not possible to assign a sub-category on basis on physico-chemical effects, and it makes no difference in classification or any other aspect in supply systems based on GHS whether a corrosive substance is category 1A, 1B or 1C as the symbol, signal word and hazard statement are all the same.

But these corrosive sub-categories apply to some authorities and in transport, assigning or changing the packing group are particularly significant as it determines the requirements for the containment system and downstream consequences relating to the transport operation. It was then decided to perform an in- vitro Corrositex test (OECD 435 test guideline) to allow this sub-categorization within 1A, 1B or 1C.

The mean breakthrough time taken for HfCl4 to produce a change in the Chemical Detection System was 7 minutes and 10 seconds, which corresponds to the UN packing group II and CLP category 1B. This assay has been scientifically validated for acid derivatives (ECVAM, 2000) and can be used for classification.

The classification proposal for irritation/ corrosion effects is then:

• C, R35 (corrosive - causes burn) under directive 67/548/EC.

• Skin. Corr. Cat 1b, H314 (Skin corrosion- causes severe skin burns and eye damage,covering the H318 phrase for severe eye damage) under CLP regulation 1272/2008.

• And as additional labeling: EUH071(Corrosive to the respiratory tract), under CLP regulation 1272/2008.