Azodicarbonamide (ADCA): A reconsideration of classification as a respiratory sensitiser.

Azodicarbonamide (ADCA) is widely used by industry in the manufacture of a variety of products. ADCA has been classified as a respiratory allergen, and the purpose of this article was to consider whether this classification is appropriate based upon the available data. Here both clinical experience and relevant experimental data have been reviewed. Although there have been reports of an association between workplace exposure to ADCA and symptoms of respiratory allergy and occupational asthma, the evidence is less than persuasive, with in many instances a lack of properly controlled and executed diagnostic procedures. In addition, ADCA fails to elicit positive responses in mouse and guinea pig predictive tests for skin sensitisation; a lack of activity that is regarded as being inconsistent with respect to respiratory sensitising potential. Collectively, the data reviewed here do not provide an adequate basis for the classification of ADCA as a respiratory allergen.

Short Time Exposure (STE) test in conjunction with Bovine Corneal Opacity and Permeability (BCOP) assay including histopathology to evaluate correspondence with the Globally Harmonized System (GHS) eye irritation classification of textile dyes.

Eye irritation evaluation is mandatory for predicting health risks in consumers exposed to textile dyes. The two dyes, Reactive Orange 16 (RO16) and Reactive Green 19 (RG19) are classified as Category 2A (irritating to eyes) based on the UN Globally Harmonized System for classification (UN GHS), according to the Draize test. On the other hand, animal welfare considerations and the enforcement of a new regulation in the EU are drawing much attention in reducing or replacing animal experiments with alternative methods. This study evaluated the eye irritation of the two dyes RO16 and RG19 by combining the Short Time Exposure (STE) and the Bovine Corneal Opacity and Permeability (BCOP) assays and then comparing them with in vivo data from the GHS classification. The STE test (first level screening) categorized both dyes as GHS Category 1 (severe irritant). In the BCOP, dye RG19 was also classified as GHS Category 1 while dye RO16 was classified as GHS no prediction can be made. Both dyes caused damage to the corneal tissue as confirmed by histopathological analysis. Our findings demonstrated that the STE test did not contribute to arriving at a better conclusion about the eye irritation potential of the dyes when used in conjunction with the BCOP test. Adding the histopathology to the BCOP test could be an appropriate tool for a more meaningful prediction of the eye irritation potential of dyes.

8-hydroxyquinolinyl azo dyes: a class of surface-enhanced resonance Raman scattering-based probes for ultrasensitive monitoring of enzymatic activity.

A series of surface-enhanced resonance Raman scattering (SERRS) based probes for the detection of lipase activity are reported. A number of novel SERRS-active 8-hydroxylquinolinyl azo dyes have been prepared and via synthetic esterification or subsequent enzymatic hydrolysis at the 8-hydroxyl position the SERRS signal can be "switched" on or off. In the first instance, the technique has been demonstrated for the successful detection of lipase from Pseudomonas cepacia, and these new compounds offer a limit of detection of 0.2 ng mL-1 enzyme, up to a 100-fold lower limit than observed for benzotriazolyl dyes used in previous studies. The chemical synthesis is straightforward and allows for facile introduction of a wide range of different masking groups, using commonly known synthetic methodologies. The potential for multiplexing analysis of enzyme activity using this technology is presented within.