Dibutyl hydrogen phosphate

Endpoint summary

Description of key information

An in-vitro test for skin corrosion on a reconstructed human epidermis was performed with the test item and showed corrosive properties in vitro. 
In an eye irritation test on rabbits, performed in 1978, the test item showed severe eye damage to the eyes. No reversibility of the effects was shown within the observation time of 7 days. 

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:

other: OECD TG 431

Principles of method if other than guideline:

The experiment was carried out on a reconstructed human epidermis EST-1000 (CeIlSystems, St. Katharinen, Germany).

GLP compliance:

yes

Test system:

human skin model

Remarks:

EST-1000 (Cell Systems, St. Katharinen, Germany)

Source species:

human

Cell type:

other: reconstructed 3D human epidermis

Vehicle:

unchanged (no vehicle)

Amount/concentration applied:

50 mL of the neat liquid test item

Duration of treatment / exposure:

incubation periods of 3 min and 60 min

Duration of post-treatment incubation (if applicable):

no post-treatment incubation period; 3 hours incubation with MRR solution

Number of replicates:

3

Irritation / corrosion parameter:

% tissue viability

Remarks:

3 min treatment

Value:

64.38

Negative controls validity:

valid

Remarks on result:

other: mean of 3 samples compared to negative control (NaCl, 0.9%, set to 100% viability)

Irritation / corrosion parameter:

% tissue viability

Remarks:

60 min treatment

Value:

1.79

Negative controls validity:

valid

Remarks on result:

other: mean of 3 samples compared to negative control (0.9% NaCl, set to 100% viability)

Compound                                   [%] Cell viability 3 min       [%] Cell viability 60 min       Classification*

test item                                                  64.36                                  1.79                            Corrosive                   

Negative control                                   100                                   100                                Negative control

* Classification was done in accordance with the existing guideline and internationally accepted protocols, i.e. evaluation of LD50 values after 3 min. and/or less than 15% viability after a 60 min. incubation period.

Substances are classified as "corrosive (R34)", if the cell viability of the EST 1000 is decreased by more than 50% after 3 min. of incubation to the test item, or if the cell viability is less than 15% after 60 min. of exposure to the test item.

Interpretation of results:

Category 1B (corrosive) based on GHS criteria

Executive summary:

A study for predicting non-specific, corrosive potentials of compounds by using reconstructed human skin (RHS) was performed. The experiment was carried out on a reconstructed human epidermis EST-1000 (CellSystems, St. Katharinen, Germany) for detection of topically applied skin corrosives with the test item dibutyl hydrogen phosphate.

Corrosive skin effects of substances are defined as irreversible damage of skin; namely, visible necrosis through the epidermis and into the dermis, following the application of a test substance for up to four hours. In vivo corrosive reactions are typified by ulcers, bleeding, and bloody scabs.

A 100% concentration was tested on the skin/epidermal equivalents in triplets. For the determination of time related cytotoxic effects the incubation periods were 3 min. and 60 min., respectively. By this the study, was conducted in accordance with the OECD 431 guideline using the test item concentrations and incubation periods recommended there. These tests are also related to the revised OECD 404 guideline "Acute Dermal Irritation/Corrosion".

The test item was applied at a 100% concentration, i.e. 50µl per insert.

The MTT (Methylthiazoletetrazolium) method has determined the following values of viability after 3 min. or after 60 min. of incubation: 64% and 2% (rounded), respectively.

Thus, the results show that a corrosive property of the test item was determined by the assay used.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (corrosive)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: scientifically acceptable and sufficient documented

Principles of method if other than guideline:

100 µl test substance was applied into the conjunctival sac of 2 rabbits. Post exposure time was 7 days. Eyes were examined after application of test substance up to 7 days.

GLP compliance:

no

Species:

rabbit

Strain:

New Zealand White

Vehicle:

unchanged (no vehicle)

Controls:

not required

Duration of treatment / exposure:

7 days

Observation period (in vivo):

7 days

Number of animals or in vitro replicates:

2 animals

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24 h

Score:

1.5

Max. score:

4

Reversibility:

not fully reversible within: 7 days

Irritation parameter:

iris score

Basis:

mean

Time point:

24 h

Score:

1

Max. score:

2

Reversibility:

not fully reversible within: 7 days

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

24 h

Score:

2

Max. score:

3

Reversibility:

not fully reversible within: 7 days

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24 h

Score:

2.5

Max. score:

4

Reversibility:

not fully reversible within: 7 days

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

48 h

Score:

1.5

Max. score:

4

Reversibility:

not fully reversible within: 7 days

Irritation parameter:

iris score

Basis:

mean

Time point:

48 h

Score:

1

Max. score:

2

Reversibility:

not fully reversible within: 7 days

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

48 h

Score:

2

Max. score:

3

Reversibility:

not fully reversible within: 7 days

Irritation parameter:

chemosis score

Basis:

mean

Time point:

48 h

Score:

3

Max. score:

4

Reversibility:

not fully reversible within: 7 days

Irritation parameter:

cornea opacity score

Time point:

72 h

Remarks on result:

not measured/tested

Irritation parameter:

iris score

Time point:

72 h

Remarks on result:

not measured/tested

Irritation parameter:

conjunctivae score

Time point:

72 h

Remarks on result:

not measured/tested

Irritation parameter:

chemosis score

Time point:

72 h

Remarks on result:

not measured/tested

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

7 d

Score:

1.5

Max. score:

4

Reversibility:

not reversible

Irritation parameter:

iris score

Basis:

mean

Time point:

7 d

Score:

1

Max. score:

2

Reversibility:

not reversible

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

7 d

Score:

2

Max. score:

3

Reversibility:

not reversible

Irritation parameter:

chemosis score

Basis:

mean

Time point:

7 d

Score:

1.5

Max. score:

4

Reversibility:

not reversible

The test substance causes corrosion to the cornea.

Interpretation of results:

Category 1 (irreversible effects on the eye) based on GHS criteria

Executive summary:

The test substance was (100 µl) was applied into the conjuctival sac of 2 rabbits. Post exposure time was 7 days. Eyes were examinated after application of test substance up to 7 days.

Effects on the cornea, iris, conjunctiva and chemosis were persistent up to the end of the observation period (7 days).

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irreversible damage)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

A study for predicting non-specific, corrosive potentials of compounds by using reconstructed human skin (RHS) was performed. The experiment was carried out on a reconstructed human epidermis EST-1000 (CellSystems, St. Katharinen, Germany) for detection of topically applied skin corrosives with the test item dibutyl hydrogen phosphate. For the determination of time related cytotoxic effects the incubation periods were 3 min. and 60 min., respectively. By this the study, was conducted in accordance with the OECD TG 431 guideline using the test item concentrations and incubation periods recommended there. The MTT (Methylthiazoletetrazolium) method has determined the following values of viability after 3 min. or after 60 min. of incubation: 64% and 2% (rounded), respectively. This result leads to classification as corrosive (Cat 1B). 

 

In an in vivo eye irritation study in rabbits, performed in 1978, the test substance was applied into the conjuctival sac of 2 rabbits. Effects on the cornea, iris, conjunctiva and chemosis were persistent up to the end of the observation period (7 days). The test substance was thus classified as severly damaging the eyes. 

 

Justification for classification or non-classification

Due to the results of an in-vitro skin corrosion study a classification as Skin Corr. 1B; H314: Causes severe skin burns and eye damage is justified according to CLP classification criteria (Regulation (EC) No 1272/2008).

Based of an in vivo eye irritation study a classification as Eye Dam.1; H318: Causes serious eye damage is justified according to CLP classification criteria (Regulation (EC) No 1272/2008).