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Toxicological information

Dermal absorption

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Administrative data

Endpoint:
dermal absorption in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
1984
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
The study seems to follow main requirements of the OECD protocol although not all information is included in publication to judge if it is followed exactly. :The test substance was not radiolabelled therefore there was no attempt at a mass balance. Not enough raw data reported to meet protocol requirements. Some minor detail of experimental methods also lacking.

Data source

Reference
Reference Type:
publication
Title:
Absorption of some glycol ethers through human skin in vitro
Author:
Dugard PH, Walker M, Mawdsley SJ, Scott RC
Year:
1984
Bibliographic source:
Env Hlth Persp, 57, 193-7

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:
See comments on reliability.
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): 2-(2-butoxyethoxy)ethanol, diethylene glycol monobutyl ether, DB
- Physical state: liquid
- Analytical purity: >98%
- Other: Source: ICI Petrochemicals and Plastics division, Wilton, UK
Radiolabelling:
no

Test animals

Species:
human
Strain:
other: not applicable
Sex:
not specified
Details on test animals and environmental conditions:
no further data on source of skin.

Administration / exposure

Type of coverage:
other: not aplicable as study in vitro
Vehicle:
unchanged (no vehicle)
Duration of exposure:
8 hours
Doses:
Single
No. of animals per group:
not applicable
Control animals:
no
Details on study design:
See other information below.
Details on in vitro test system (if applicable):
SKIN PREPARATION
- Source of skin: Obtained post mortem, source unknown.
- Ethical approval if human skin: no data
- Type of skin: Abdominal whole skin
- Preparative technique: Subcutaneous fat removed, then immersed in water (60C, 45 seconds) to allow separation of epidermis. Discs then cut for diffusion cells (1.8cm2 absorption area).
- Membrane integrity check: By following time dependent diffusion of tritiated water before and after exposure to the substance. Skin samples showing a tritiated water permeability greater than 0.0015cm/hr over 6 hours were rejected.

PRINCIPLES OF ASSAY
- Solubility of test substance in receptor fluid: complete
- Static system: Yes
- Test temperature: 30C

Results and discussion

Signs and symptoms of toxicity:
not specified
Remarks:
not applicable
Dermal irritation:
not specified
Remarks:
not applicable
Absorption in different matrices:
not applicable
Total recovery:
not applicable
Conversion factor human vs. animal skin:
no data

Any other information on results incl. tables

Steady state was achieved during the experiment; maximum rate was achieved after 5 hours. At 2.5hours the adsorption rate was less than that of the 5 hour rate, generally showing a 2 hour lag time. The permeability constant was calculated at 0.0000357cm/hr with a rate of absorption of 0.035 +/-0.025mg/cm2/hr, based on 9 determinations. The damage ratio (ratio of tritiated water permeability before and after exposure) was 2.05+/-1.01 (5 determinations) which is within the 1-2 figure for controls leading to the conclusion that 2-(2-butoxyethoxy)ethanol dose not have any significant irreversible effects on skin barrier function.

Applicant's summary and conclusion

Conclusions:
skin uptake is unlikely to be a significant route of exposure
Executive summary:

An in vitro dermal absorption study using human skin showed that 2 -(2 -butoxyethoxy)ethanol is able to pass through the stratum corneum but only at a slow rate (35ug/cm2/hr) and does so without causing any significant detectable damage to the skin. There is a lag time of approximately 2 hours for substance to cross the skin and appear in the receptor fluid