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Toxicological information

Dermal absorption

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Administrative data

Endpoint:
dermal absorption in vitro / ex vivo
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non-GLP, non-guideline in-vitro and animal experimental study, published in peer reviewed literature, minor restrictions in reporting but otherwise adequate for assessment.
Cross-reference
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
2005

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 428 (Skin Absorption: In Vitro Method)
Principles of method if other than guideline:
Skin penetration and skin retention studies (with mass balance determination) were conducted.
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): xylene
- Molecular formula: C6H6-(CH3)2
- Molecular weight: 106.17
- Substance type: hydrocarbon
- Isomers composition: no data
- Radiochemical purity (if radiolabelling): 98.0%
- Melting point: -25.2°C
- Boiling point: 144.5 °C
- Log Kp: 3.12
- Water solubility (mg/L): 178
Radiolabelling:
yes

Test animals

Species:
rat
Strain:
other: CD
Sex:
not specified

Administration / exposure

Type of coverage:
occlusive
Vehicle:
unchanged (no vehicle)
Duration of exposure:
8 hr
Doses:
- Dose volume: 0.5 ml containing 2.5 µCi per cell
No. of animals per group:
9
Control animals:
no
Details on in vitro test system (if applicable):
Skin penetration and skin retention studies (with mass balance determination) were conducted.

Results and discussion

Absorption in different matrices:
The in-vitro dermal penetration of xylene through rat skin was 0.224% in 8 hours.

Total recovery:
94.21±2.61% at 8h.
Percutaneous absorption
Parameter:
percentage
Absorption:
0.2 %
Remarks on result:
other: 8h
Remarks:
The flux of xylene through rat abdominal skin was 0.0037 mg/cm2/min

Any other information on results incl. tables

Xylene showed a lag time of about 1 h. Retention in the stratum corneum was much higher than epidermis and dermis at all time points. Under infinite dose conditions, xylene diffused rapidly into the stratum corneum and reached plateau levels within 3 h. The recovery (mass balance) for xylene was 92-105%. This indicated a minimum evaporation of chemical during the skin retention study.

Applicant's summary and conclusion

Conclusions:
The in-vitro dermal penetration of xylene through rat skin was 0.224% in 8 hours.