Reaction mass of 2-Piperazin-1-ylethanol and Piperazine-1,4-diethanol and Piperazine

Endpoint summary

Description of key information

Skin irritation: corrosive (OECD 431, GLP, BASF 2012)
Eye irritation: no data available, due to corrosive properties at the skin corrosive properties to the eyes are expected.

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP Guideline Study

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)

GLP compliance:

yes (incl. QA statement)

Remarks:

Experimental Toxicology and Ecology, BASF SE, 67056 Ludwigshafen, Germany

Species:

other: in vitro: EpiDerm

Strain:

other: not applicable

Type of coverage:

other: not applicable

Preparation of test site:

other: not applicable

Vehicle:

unchanged (no vehicle)

Controls:

other: not applicable

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 50 µL

Duration of treatment / exposure:

3 minutes at room temperature and 1 hour in the incubator (37°C)

Observation period:

not applicable

Number of animals:

not applicable

Details on study design:

Two tissues per exposure time (3 minutes at room temperature or 1 hour in the incubator, as a rule) and test group (test material, negative control (NC) and positive control (PC); 12 tissues per test) were used. In addition, one killed tissue per exposure time was treated with the test substance and NC, respectively, in order to detect direct MTT reduction. Control tissues were concurrently applied with 50 μL of de-ionized water (NC) or with 50 μL of 8 n potassium hydroxide (PC) or test substance (killed tissue control, KC).
Tissue destruction was determined by measuring the metabolic activity of the tissue after exposure using a colorimetric test. The reduction of mitochondrial dehydrogenase activity, measured by reduced formazan production after incubation with a tetrazolium salt (MTT) was chosen as endpoint. The formazan production of the test substance treated epidermal tissues is compared to that of negative control tissues. The quotient of the values indicates the relative tissue viability.

Acceptance criteria:
In case one of the below given acceptance criteria is not covered, repetition of the test was considered.
Assay acceptance criterion for the negative control (NC):
The absolute OD570 of the negative control tissues in the MTT test is an indicator of tissue viability obtained in the testing laboratory after the shipping and storing procedure and under specific conditions of the assay. Tissue viability is acceptable if the mean OD570 of the NC is ≥ 1.0. The mean OD570 of the NC should not exceed 2.5.

Assay acceptance criterion for the positive control (PC):
Potassium hydroxide as 8.0 normal ready made solution is used as positive reference. A 3-minute treatment with 8.0 n KOH usually reveals a mean relative tissue viability of ~20%. An assay is acceptable if mean relative tissue viability of the 3 min positive control is ≤ 30%.

Assay acceptance criterion for tissue variability:
For every treatment, except the killed controls, 2 tissues corrosion test are treated in parallel. The inter-tissue variability is considered to be acceptable if the difference of the OD570 values of the two tissues is ≤ 0.3 (corrosion test).

Assay acceptance criterion for killed controls (KC):
The OD570 of the killed control tissues treated as negative control should be ≤ 0.35.

Evaluation criteria:
Corrosive potential of the test materials is predicted from the mean relative tissue viabilities obtained after 3 min treatment compared to the negative control tissues concurrently treated with de-ionized water. A chemical is considered as "corrosive", if the mean relative tissue viability after 3 min treatment with a test material is decreased below 50%. In addition, those materials with a viability of ≥ 50% after 3 min treatment are considered as "corrosive" if the mean relative tissue viability after 1 hour treatment with a test material is decreased below 15%. Although the method is not finally validated for categorizing the severity of corrosivity according to certain classification and labeling systems, it is suggested to use the most stringent category for test substances leading to viabilities below 50% after 3 min treatment.

Irritant / corrosive response data:

After 3 minute exposure with the test substance the viability was 95% and after 1 hour 13%, respectively.

Results:

		Exposure: 3 min				Exposure: 1 hour
Test substance		tissue 1	tissue 2	KC	mean	tissue 1	tissue 2	KC	mean
NC	mean OD570	1.918	1.922	0.187	1.92	1.93	1.774	0.176	1.852
	viability [% of NC]	99.9	100.1	-	100	104.2	95.8	-	100
test substance	mean OD570	1.821	1.831	0.191	1.826	0.233	0.235	0.195	0.234
	viability [% of NC]	94.8	95.4	-	95	12.6	12.7	-	13
PC	mean OD570	0.399	0.293	-	0.346	0.166	0.217	-	0.192
	viability [% of NC]	20.8	15.2	-	18	9.0	11.7	-	10

Due to the ability of the test substance to reduce MTT directly, a KC was applied in parallel.

However, the result of the KC did not indicate an increased MTT reduction (difference to KC of NC is not greater than 0.1). Thus the KC was not used for viability calculation.

Interpretation of results:

corrosive

Remarks:

Migrated information

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (corrosive)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

The potential of hydroxyethylpiperazine mixture to cause dermal corrosion/irritation was assessed by two in vitro GLP guideline studies (OECD 431/439) by BASF in 2012 (BASF 2012 a, b). In order to evaluate the irritant/corrosive properties a single topical application of 50 μL (corrosion test) or 30 μL (irritation test) of the test substance was applied to a reconstructed three dimensional human epidermis model (EpiDerm™). For the corrosion test two EpiDerm™ tissue samples were incubated with the test substance for 3 minutes and 1 hour, respectively. The irritation test was performed with three EpiDerm™ tissue samples, which were incubated with the test substance for 1 hour followed by an about 42-hours post-incubation period. Tissue destruction was determined by measuring the metabolic activity of the tissue after exposure/post-incubation using a colorimetric test. The reduction of mitochondrial dehydrogenase activity, measured by reduced formazan production after incubation with a tetrazolium salt (MTT) was chosen as endpoint. The formazan production of the test substance treated epidermal tissues is compared to that of negative control tissues. The quotient of the values indicates the relative tissue viability. The EpiDerm™ skin corrosion/irritation test showed the following results:

The test substance is able to reduce MTT directly. However, this ability of direct MTT reduction did not impair the study result as demonstrated by the concurrently performed exposure of control tissues inactivated by freezing (performed with corrosion test, only).

Corrosion test: The mean viability of the test substance treated tissues determined after an exposure period of 3 minutes was 95%, and it was 13% after an exposure period of 1 hour.

Irritation test: The mean viability of the test substance treated tissues determined after an exposure period of 1 hour with about 42 hours post-incubation was 8%.

Based on these results it was concluded, that hydroxyethylpiperazine mixture shows a corrosive potential in the EpiDerm™ skin corrosion/irritation test under the test conditions chosen.

In conclusion, hydroxethylpiperazine mixture has to be classified as corrosive to skin and therefore, corrosivity also is expecteed for the eyes. Thus, no testing for eye irritation/corrosion is further justified.

Justification for selection of skin irritation / corrosion endpoint:
key study

Effects on skin irritation/corrosion: corrosive

Justification for classification or non-classification

Dangerous Substance Directive (67/548/EEC)

The available studies are considered reliable and suitable for classification purposes under 67/548/EEC. As a result the substance is considered to cause severe skin burns and eye damage (R34) under Directive 67/548/EEC, as amended for the 28th time in Directive 2001/59/EC.

 

Classification, Labeling, and Packaging Regulation (EC) No. 1272/2008

The available experimental test data are reliable and suitable for classification purposes under Regulation 1272/2008. As a result the substance is considered to be corrosive (Skin Cat. 1B and Eye damage Cat. 1) under Regulation (EC) No. 1272/2008.