Placement and Handling of Dermal Dosimeters

  • Dermal patch dosimeters often consist of 3x3 or 4x4 inch, 12-ply, gauze sponges, backed with a 4 to 6 sheet of polyethylene; placing this sandwich in a commercially available protective aluminized paper envelope with a circular open collecting area is a convenient way to protect the dosimeter from mechanical damage and minimize cross contamination while handling. Such a 3x3 dosimeter would have a collecting area of 25.65 cm²; a 4x4 dosimeter, 42.03 cm².
  • Dosimeters for the hands are simply light cotton knit, absorbent gloves.
  • Rinsing the hands is either an additional or an alternative method to glove dosimeters. Washing solutions might be pure water, water and surfactant (detergent), or a weak organic solvent like an alcohol. Washing methods might entail manual rubbing in a solution in a beaker or plastic bag, or wiping with a wetted cotton sponge. The hand rinse samples would be stored, extracted for the chemical of interest, and analyzed separately from a glove if used.
  • There are no standard procedures for attaching the dosimeters.
    • One scheme for dermal dosimeters worn under normal work clothes is to pre-attach those for the torso and upper arms to a tight fitting T-shirt; those for the lower arms and legs may be pre-attached to elastic bands with a Velcro release; as an alternative those for the legs have also been attached to net chaps.
    • Dosimeters worn over normal work clothes have been pre-attached to a 1½-inch open net smock covering the chest, back, upper arms, and upper legs; those placed on the head, lower arms, lower legs may be pinned or attached via duct tape to the wearer's clothing.
    • The dermal dosimeters were put in place before exposure began and remained in place throughout the duration of exposure. Note how the pattern in Table 2 avoids placing any inner dosimeter beneath an outer dosimeter.
  • It is implicit in any use of dosimeters that the chemical to be assessed is stable on the matrix, that it can be efficiently extracted, and that there is no background or interference with its analysis. While such assurance should be established before sampling, field spikes prepared from spiking solutions and field blanks are usually prepared, handled, and analyzed at about a 1:10 ratio with field samples to further assure dosimeter accuracy for the particular compound.
  • During application, the Field Investigator should record information about:
  1. the site: its location, indoors or out, amount of product used, type of equipment being used.
  2. the environment: temperature, humidity, air velocity and direction with respect to applicator and work, exposure time.
  3. the clothing worn: work clothing (coveralls, jacket, hat or cap, etc.) and protective clothing (gloves, goggles, face shield, respirator, etc.).
  4. any occurrence of visible skin wetting or saturation and the surfaces and approximate areas involved.