Type 1 latex allergy most commonly manifests as localized urticaria after contact of skin with natural rubber but can also include symptoms of allergic rhinoconjunctivitis, asthma and rarely anaphylaxis. This immediate (Type I) allergy is caused by natural proteins inherent to the rubber tree, which remain on the finished natural rubber products. The quantification of protein levels in NRL products using the standard colorimetric protein assays may give spurious results due to chemical additives in the latex formulations that interfere with the assay (2,3). Furthermore, the amount of protein found in NRL products are often below the detection limits of the standard colorimetric protein assay (4,5).

This test method describes an immunological method for quantitation of natural rubber latex proteins using rabbit anti-NRL serum. Rabbits immunized with NRL proteins react to the majority of the proteins present, and their sera have the capability to detect most if not all of the proteins in NRL. Therefore, although rabbit antibody reacts with antigenic material, this should not be considered as quantitative measure of total protein levels.

1.1 This test method covers an immunological method to determine the amount of antigenic protein in natural rubber and its products using rabbit antisera specific for natural rubber latex (NRL) proteins. This immunoassay procedure quantitatively measures the level of antigenic latex proteins in solution using an inhibition format. The samples may include glove or other rubber product extracts which have been collected in order to measure the latex protein levels. Although this method detects antigenic proteins, it should not be considered as a measure of allergenic proteins. Correlation of protein/antigen levels with the level of allergenic proteins has not been fully established.

1.2 For the purpose of this test method, the range of protein will be measured in terms of microgram to milligram quantities.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.