Determination of the dusting potential and endotoxin activity of three batches of Amino acid zootechnical mixture

Three batches of a new product were provided by Metex-Noovistago France, for analysis of dustiness and endotoxin content. The product consists of a mixture of three amino acids (L-arginine (L-Arg), L-glutamine (L-Gln), L-threonine (L-Thr)) and a dry plant extract (grape extract of Vitis Vinifera spp. Vinifera). The area of application of the new product is to be used for animal nutrition. Methods applied were conform to those proposed by EFSA (EFSA Journal 2012;10(1):2539)3, i.e. the Stauber-Heubach analysis determining the dust potential and light scattering to determine the particle size distribution. Endotoxin activities were determined by the Limulus amoebocyte lysate (LAL) test. From the analysis of the particle size distribution and endotoxin content, classification of representative samples of the three batches of the product was achieved. More specifically from these experiments, the following conclusions are drawn: - For the three batches a comparable amount of dust was generated in the Stauber-Heubach test. The three batches have similar, bimodal, particle size distributions consisting of relatively small particles with peak positions at few hundreds of nm and at 4-7 microns. - All three batches can be classified as “moderate” for inhalable, and “high” for thoracic and respirable potentials. - Endotoxin levels varied among the different batches and were relatively low, being 74.1, 51.3 and 104.9 EU/mg for respectively batch AA Mix#1, AA Mix#2 and AA Mix#3. The data obtained can be used for the calculation of inhalation exposure under practical conditions in a factory.