Zinc bis(dihydrogen phosphate)

Endpoint summary

Description of key information

The in vitro skin irritation test in the EpiDerm model with zinc bis(dihydrogen phosphate) indicates that the test item is non Irritant and non-corrosive.
While no in vivo data exists on zinc bis(dihydrogen phosphate), only limited in vitro data in the HET-CAM  test suggests zinc bis(dihydrogen phosphate) is moderately irritating to eyes.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

GLP compliance:

yes (incl. QA statement)

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

skin obtained from plastic surgery from multiple donors

Vehicle:

physiological saline

Details on test system:

TEST SITE
- Area of exposure: after moistening the EpiDerm tissue with 25µl PBS before dosing, 25 mg of the test article was added into the Millicell atop the tissue

REMOVAL OF TEST SUBSTANCE
- Washing (if done): at the end of the exposure period, each EpiDerm tissue was rinsed with phosphate buffered saline (PBS)
- Time after start of exposure: test article remained in contact with the EpiDerm tissue for 60 minutes.

SCORING SYSTEM:
After washing EpiDerm tissue was transferred to a 24 well plate contaiing 300µl MTT solution. Afterwards the tissues were returned to the incubator for a three-hour MTT incubation period. Following MTT incubation period, each EpiDerm tissue was rinsed with PBS and then treated overnight with 2.0 ml of extractant solution (isopropanol) per well. The absorbancy of an aliquot of the extracted MTT formazan was measured at 540nm using a microplate reader.

Analysis of data:
The mean absorbance value for each time point was calculated from the optical density (OD) of the duplicate samples and expressed as percent viability for each sample using the following formula:
% viability= 100x(OD sample/OD negative control)

Quality controls: negative controls meets the acceptance criterion if the mean OD of the 2 tissues each time point is greater than or equal to 1.0 and smaller than or equal to 2.5. The positive controls meets the acceptance criterion if the mean relative tissue viability, expressed as percentage of the negative control tissues is less than or equal to 20%
the SD calculated from individual percent tissue viabilities of the three identically treated replicates is less than 18%

Amount/concentration applied:

25 mg

Duration of treatment / exposure:

60 min

Irritation / corrosion parameter:

% tissue viability

Value:

92.1

Remarks on result:

other:

Remarks:

Basis: mean. Time point: 60min. Remarks: recovery period: 42h. (migrated information)

Interpretation of results:

GHS criteria not met

Conclusions:

Following exposure with Zinc bis(dihydrogen phosphate), the mean treated skin value was 92.1% and therefore non irritant. All validity criteria were within acceptable limits and therefore the study can be considered as valid.

In this in vitro skin irritation test in the EPISKIN model with Zinc bis(dihydrogen phosphate) the results indicated that the test item is Non Irritant (NI) [UN GHS: No Category].

Executive summary:

A study was conducted to predict dermal irritation potential of Zinc bis(dihydrogen phosphate) in the context of identification and classification of skin irritation hazard according to the EU classification (R38 or no label) and GHS classification system (category 2 and non-irritants) by using a three-dimensional human epidermis model (OECD 439). MatTek EpiDerm tissue samples were treated in triplicate with the test article, negative control and positive control for 60 minutes. Following treatment and subsequent incubation time, the viability of the tissues was determined using MTT uptake and conversion, and the absorbance of each sample was measured at 540nm. The viability was then expressed as a percent of control values.

In this in vitro EPIDERM model test with Zinc bis(dihydrogen phosphate), the results indicate that the test item is non irritant.

Reference 2

Endpoint:

skin corrosion: in vitro / ex vivo

Remarks:

in vitro

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

skin obtained from plastic surgery from multiple donors

Vehicle:

water

Details on test system:

TEST SITE
- Area of exposure: approximately 25 mg of the test article + 25 µl tissue culture water (negative control) were applied on the top of each EpiDerm tissue (9mm in diameter)

REMOVAL OF TEST SUBSTANCE
- Washing (if done): at the end of the exposure period, each EpiDerm tissue was rinsed with phosphate buffered saline (PBS)
- Time after start of exposure: test article remained in contact with the EpiDerm tissue for 3 and 60 minutes.

SCORING SYSTEM:
After washing EpiDerm tissue was transferred to a 24 well plate contaiing 300µl MTT solution. Afterwards the tissues were returned to the incubator for a three-hour MTT incubation period. Following MTT incubation period, each EpiDerm tissue was rinsed with PBS and then treated overnight with 2.0 ml of extractant solution (isopropanol) per well. The absorbancy of an aliquot of the extracted MTT formazan was measured at 540nm using a microplate reader.

Analysis of data:
The mean absorbance value for each time point was calculated from the optical density (OD) of the duplicate samples and expressed as percent viability for each sample using the following formula:
% viability= 100x(OD sample/OD negative control)

Quality controls: negative controls meets the acceptance criterion if the mean OD of the 2 tissues each time point is greater than or equal to 0.8. The positive controls meets the acceptance criterion if the mean relative tissue viability at the 3 minute time point is less than or equal to 30%
Inter-tissue viability meets the acceptance criterion if the difference between two identically treated tissues is no greater than 30%

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied: 25 mg of the test article, plus 25 ul tissue culture water were applied to the top of each EpiDerm tissue

Duration of treatment / exposure:

3 and 60 min

Details on study design:

TEST SITE
- Area of exposure: approximately 25 mg of the test article + 25 µl tissue culture water (negative control) were applied on the top of each EpiDerm tissue (9mm in diameter)

REMOVAL OF TEST SUBSTANCE
- Washing (if done): at the end of the exposure period, each EpiDerm tissue was rinsed with phosphate buffered saline (PBS)
- Time after start of exposure: test article remained in contact with the EpiDerm tissue for 3 and 60 minutes.

SCORING SYSTEM:
After washing EpiDerm tissue was transferred to a 24 well plate contaiing 300µl MTT solution. Afterwards the tissues were returned to the incubator for a three-hour MTT incubation period. Following MTT incubation period, each EpiDerm tissue was rinsed with PBS and then treated overnight with 2.0 ml of extractant solution (isopropanol) per well. The absorbancy of an aliquot of the extracted MTT formazan was measured at 540nm using a microplate reader.

Analysis of data:
The mean absorbance value for each time point was calculated from the optical density (OD) of the duplicate samples and expressed as percent viability for each sample using the following formula:
% viability= 100x(OD sample/OD negative control)

Quality controls: negative controls meets the acceptance criterion if the mean OD of the 2 tissues each time point is greater than or equal to 0.8. The positive controls meets the acceptance criterion if the mean relative tissue viability at the 3 minute time point is less than or equal to 30%
Inter-tissue viability meets the acceptance criterion if the difference between two identically treated tissues is no greater than 30%

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

after 3 min

Value:

95.6

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

after 60 min

Value:

88.2

Interpretation of results:

GHS criteria not met

Conclusions:

In this in vitro EPIDERM model test with Zinc bis(dihydrogen phosphate), the results indicate that the test item is not a skin corrosive.

Executive summary:

A study was conducted to predict and classify the skin corrosivity potential of Zinc bis(dihydrogen phosphate) by using a three-dimensional human epidermis model (OECD 431). MatTek EpiDerm tissue samples were treated in duplicate with the test article, negative control and positive control for 3 minutes and 60 minutes. Following treatment, the viability of the tissues was determined using MTT uptake and conversion, and the absorbance of each sample was measured at 540nm. The viability was then expressed as a percent of control values.

In this in vitro EPIDERM model test with Zinc bis(dihydrogen phosphate), the results indicate that the test item is not a skin corrosive.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation

Remarks:

other: Hen´s Egg Test on the Chorioallantoic Membrane (HET-CAM)- reaction time method

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2006

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Shortly documented, scientifically good . According to GLP and to Alternative methods currently available to the Draize rabbit eye test

Qualifier:

no guideline available

Principles of method if other than guideline:

Hen´s Egg Test Chorioallantoic Membrane (HET-CAM) test permits the identification of irritative reactions which appear to be similar to those which occur in the eye using the standard Draize rabbit eye test. In the HET-CAM test system, three reactions are determined: haemorrhage, lysis and coagulation of the chorio-allantoic membrane at the ninth day of embryonation when nerve tissue and pain perception have not yet developed.

GLP compliance:

yes

Species:

other: hen's eggs

Strain:

not specified

Vehicle:

unchanged (no vehicle)

Controls:

other: eggs treated with reference substance

Amount / concentration applied:

0.3ml of the 10% mixture of the test article (1g of test article was mixed with distilled water to a total volume of 10ml)

Duration of treatment / exposure:

5 minutes

Observation period (in vivo):

5 minutes

Number of animals or in vitro replicates:

6 White Leghorn eggs per test substance

Irritation parameter:

other: relativ irritation potential

Basis:

mean

Score:

0.99

Remarks on result:

other: relativ irritation potential (Q)

Other effects:

No other effects

Substance (undiluted)	Conc (% free H3PO4)	SAT (intern batch nr)	relativ irritation potential (Q)	SD  ±	Assessment
phosphorsäure	4.5	060236	0.96	0.13	moderately irritating *
zinkphospat-lösung 2 (zink-bis-dihydrogenphosphat, 14.6%)	4.5	060237	0.99	0.05	moderately irritating *
zinkphospat-lösung 2, verdünnt (faktor 1.72 mit wasser) (zink-bis-dihydrogenphosphat, 14.6%)	2.6	060252	0.99	0.09	moderately irritating *
referenzsubstanz 'Texapon ASV'	5% AS	050359	1.00	0.04	moderately irritating

* extravasale Koagulationsnachweis: positiv

Interpretation of results:

moderately irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Test substance, zinkphospat-lösung 2 (zink-bis-dihydrogenphosphat, 14.6%), as undiluted, is moderately irritating. Slight extravasale coagulation is assessed.

Executive summary:

The aim of this study is to evaluate the potential ocular irritancy of a test substance as measured by its ability to induce toxicity in the chorioallantoic membrane of a hen. Effects are measured by the onset of: (1) hemorrhage; (2) coagulation; and (3) vessel lysis. These assessments are considered individually and then combined to derive a score, which is used to classify the irritancy level of the test substance.

Based on the relative irritation potential (Q), the test substance, as undiluted, is moderately irritating

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

In vitro data shows that zinc bis(dihydrogen phosphate) was not irritating to skin and therefore does not require classification as a skin irritant.

The only limited in vitro data in the HET-CAM test suggests zinc bis(dihydrogen phosphate) is moderately irritating to eyes but however no classification is to be assigned.