Effect of air transport on acrylate/methacrylate allergens in syringes and IQ chambers.

Three methacrylate allergens, methyl methacrylate (MMA), 2-hydroxyethyl methacrylate (2-HEMA), and ethyleneglycol dimethacrylate (EGDMA), were purchased from Chemotechnique Diagnostics (Vellinge, Sweden). These were compounded in 2.0% wt/wt petrolatum (pet.) and inserted into capped polypropylene syringes (with and without aluminium foil wrapping) and IQ chambers (Chemotechnique Diagnostics) without aluminium foil. Approximately 4 ml of each preparation was inserted into a syringe and approximately 30 mg of preparation into each polyethylene IQ chamber. The tape with the chambers was protected by the manufacturer’s stiff plastic cover with 10 compartments that correspond to the chambers on the tape. The syringes were sent in triplicate for each allergen with and without aluminium foil wrapping, and two unwrapped samples in IQ chambers for each methacrylate were sent. These were then packaged in an airtight plastic bag and sent via normal airmail to the National Skin Centre, Singapore. Upon receipt of the packaging, the allergens were then sent back to the Malmö department immediately, without being opened in Singapore. The estimated travelling time was approximately 28 hr by air and at least 4 hr on land. Upon arrival back at our laboratory, the allergens in the syringes and IQ chambers were analysed by highperformance liquid chromatography (to be published) for actual methacrylate allergen content. The detection limit for the allergens in the system that we used was 0.00011%. The results are shown in Table 1. After allowing for the allergen loss due to our compounding process, we found that the patch test preparations sent in capped syringes retained their original allergen concentration whether or not they had been wrapped in aluminium foil, whereas those in IQ chambers with lids but without aluminium foil wrapping had lost almost their entire allergen content, for MMA and 2-HEMA in particular.