Microbial feed additives are mostly powder or granule
formulations. Therefore, exposure for the operator is most likely to occur via skin contact or inhalation. The formulated
commercial product should be examined for skin irritancy
using validated laboratory animal tests and, when appropriate,
also for eye irritation. Skin sensitisation tests are also
recommended, in case there is any reason to suspect that the
preparation contains components that may be able to penetrate
the skin. With respect to respiratory sensitisation,
microbial additives are regarded as sensitisers, unless there is
evidence to the contrary. Protective measures to minimise
the exposure are, therefore, recommended and specific studies
on the dusting properties and particle size are required in
order to estimate distribution of the inhalable fraction.