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Evaluation of the sensitization potential of two chemicals, methyl red and basic fuchsin, with potential use in indicator pads.
American Industrial Hygiene Conference and Exposition, May 8-13, 2004, Atlanta, Georgia. Fairfax, VA: American Industrial Hygiene Association, 2004 May; :82
With allergic and irritant contact dermatitis comprising up to 25% of all reported occupational diseases, there is a need to improve intervention strategies to avoid dermal chemical exposures. Likewise, improved methods for evaluating the efficacy of personal protective devices are needed. To meet this need indicator pads, worn under protective clothing and chemical resistant gloves, are being developed to detect potential chemical exposures. These studies were conducted to evaluate the sensitization potential of chemicals being evaluated for use in indicator pads. Methyl Red (CAS 845-10-3) and Basic Fuchsin (CAS 569-61-9) were evaluated using the local lymph node assay (LLNA) and phenotypic analysis (PA) of draining lymph node cells. Female BALB/c mice (n = 5) were topically exposed on the dorsal ear pinna for 3 (LLNA) or 4 (PA) consecutive days. In the LLNA, mice were injected i.v. with 3H-thymidine on day 6 and draining lymph nodes were radioassayed. For PA, on day 10 post initial exposure, draining lymph node cells were stained with FITC labeled rat anti-mouse IgE or PE labeled rat anti-mouse CD45 B220. Blood was collected at the time of sacrifice for analysis of total serum IgE. Methyl Red tested positive in the LLNA with a calculated EC3 value (concentration required to induce a stimulation index of 3) of 0.2% or 50 ug/cm2. PA demonstrated an elevation in B220+ cells, supporting the LLNA results. No increase in total serum IgE was detected. Preliminary studies testing Basic Fuchsin demonstrated negative results in the LLNA at concentrations as high as 2.5%. These studies indicate the potential for Methyl Red to induce contact sensitization with no evidence of an IgE inducing potential. Although indicator pads contain low concentrations of these chemicals, appropriate care should be taken to avoid dermal contact to minimize the possibility of adverse effects.
Sensitization; Allergic-dermatitis; Contact-dermatitis; Occupational-diseases; Personal-protective-equipment; Protective-clothing; Gloves; Laboratory-animals; Animals; Animal-studies
American Industrial Hygiene Conference and Exposition, May 8-13, 2004, Atlanta, Georgia
Page last reviewed: April 12, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division