BS ISO 16000-21:2013 pdf free

BS ISO 16000-21:2013 pdf free.Indoor air一Detection and enumeration of moulds一Sampling from materials
Direct contact plates (see 7.1.2) and the tape-lift method (see 7.1.3) are used to sample surfaces of materials. In addition, sterile swabs can be used for surface sampling on surfaces that are not accessible to agar plates [e.g. corners, chinks (see 7.1.4)]. These surface sampling methods provide only semiquantitative results. Presenting the measurement result in terms of “colony-forming units (cfu) perunit area” is not recommended, as a dense mould layer will normally form on surface samples of infested materials and some moulds can overgrow or inhibit competing species. A more appropriate approach is the description of the population density on the culture medium (e.g. sporadic, high, dense layer).
Identification of mould species provides more information compared to mould quantification. For very clean surfaces (sterility testing), quantification can be anticipated by the direct plate method since no or only very few colonies are expected to grow on the agar surface.
The tape-lift method transfers the moulds from the material surface to a transparent adhesive film. For this purpose, press the adhesive tape carefully against the material surface to be sampled and then pull it away. Stick the tape with the adhering moulds to a document plastic folder with grained surface, place it into a clean transport bag, and ship it to the laboratory for analysis. Alternatively, stick the adhesive tape to a microscope slide or a clean transparent plastic bag.
NOTE 1 In case of only few mould or surface material adhering to the tape, the use of microscope slides or clean transparent plastic bags is not convenient because it will be difficult to remove the tape without warping or breaking it.
Tape-lift samples are directly used for microscopy. Bulk material samples can be analysed by direct microscopy using preparations produced from the material samples (e.g. disintegrated material pieces,cross sections, wash-out preparations). The microscopic analysis offers the advantage that suspected mould growth on/in the material can be confirmed by detection of mycelium.BS ISO 16000-21 pdf download.