Sampling Technique

NIOSH 9111 SAMPLING TECHNIQUE

Method 1 Concentric Squares:

Used on hard surface such as glass, ceramic, tiles etc. Take the gauze out of the vial & unroll it to create a flat surface. Within the template window, using firm pressure, wipe in a clock wise direction from one of the corners of the inside of the template window working your way in to the middle (see diagram below – Fig 1.) Finishing with a scooping motion. Take the gauze & without touching anything else, fold the side you’ve just used to the inside & reveal a clean side. Again, using firm pressure wipe over the same area again in the same direction (see diagram Fig. 2) again finishing with a scooping motion. Fold the gauze again and place it back it the vial.

Method 2 – Side to Side:

Used on painted gib, pinex, smooth timber, etc. Take the gauze & unfold it to create a flat surface, then firmly wipe within the template in a side to side (zig zag) action, completing the action in at least 5 wipes, see Fig. 3 below. Finish with a scooping motion. Turn the used side to the inside, then wipe again in an up & down action completing the action in at least 5 wipes, (Fig.4) finishing with a scooping motion. Again fold the gauze to expose another clean surface & wipe again in a side to side action (Fig. 5) Fold the gauze & place it back in the vial.

Method 3 – Blotting:

Good for rough surfaces such as particle board and exposed timber. Take the gauze out of the vial and use a dabbing motion. Dab the gauze on to the surface within the template window, lift the gauze then dab to the right slightly overlapping as you go. Do this at least 5 times within the window of the template until your reach the right hand side.  Dab just underneath your last dab & move to the left in the same manner zig-zagging your way to the bottom of the template window as per Fig. 6. Once at the bottom fold the used side to the inside, exposing a clean surface then begin dabbing from the top left of the window to the bottom left of the window and use the same zig-zagging overlapping method as before (Fig. 7) Again use a minimum of 5 dabs per line until you reach the right side of the template. Fold the gauze again & place it back in the vial.

The report you will receive back from the laboratories will show the result in ug/sample and not in ug/100cm2.

Note:  (Detailed Test) (Post decontamination)

  1. Use new gloves each sample you take to reduce the possibility of cross contamination.
  2. Take one sample for every 10m2 of the floor space in a room or part thereof
  3. If you are taking sample on varnished surface, heat pumps, vent etc.  Take another one from a lower contaminated area
  4. If you are taking sample on wallpaper, bare plasterboard, concrete, bare timber etc. take another sample in an area where contamination may be higher.
  5. Field blank – 1 in every 20 samples