A & L Biologicals - 2140 Jetstream Rd, London, ON, N5V 3P5 (519) 457-2575

Environmental Sampling

Guidelines for Microbiological Sponge Sampling Method


Water resistant markers                  Cooler with gel ice packs
Sterile Whirl Pac bags                    Rubber gloves
DE Neutralizing buffer
Pre-hydrated sterile sponge pack or sterile sponges


  1. Wash hands before sampling.
  2. Select the areas to be sampled.
  3. Label the outside of the sterile sample bag with sample identification information.
  4. Put on a new pair of disposable rubber gloves without touching outside surface of gloves. Only handle cuff portion of gloves. Gloves are only used once and then discarded.


If utilizing the pre-hydrated sponge pack:

  1. Break the seal on the sterile sample bag.
  2. Proceed to the first sample area and remove a sponge from the sample bag with gloved hand.
  3. Drag sponge (with excess liquid gently squeezed out) across a defined area (preferably 4”X4”, ~ 100 cm2) in back and forth “grid” to completely cover the area. Change the face of the sponge and repeat perpendicular to the first sampling in the same 100 cm2 area.
  4. Return the sponge in the original sterile bag with gloved hand
  5. Remove and discard gloves. Only used once per sample.
  6. Push out air in bag by pressing on the outside of the bag.
  7. Fold down top of bag approximately 4 times.
  8. Close bag tightly by folding wire tabs across bag.
  9. If taking a composite sample, go to the next sample area and repeat steps 5 -12 with a new sponge until all sub-samples have been taken.
  10. Place the samples into a cooler with sufficient blue ice to maintain the as sampled condition during transport to the laboratory facility.


If utilizing dehydrated sponges:

  1. Break the seal on the sterile sample bag.
  2. Open the sterile sample sponge bag and place the sponge in the sterile sample bag. If taking a composite sample repeat this step for the number of sub-samples to be taken.
  3. Pour sufficient neutralizing buffer solution into the sample bag to hydrate all of the sponges in the bag.
  4. Proceed to the first sample area and remove a sponge from the sample bag. Go to steps 3 – 10 for the pre-hydrated sponges.


  1. If using water based ice, ensure that it is double-bagged to prevent contamination of the sample.
  2. Health Canada has a detailed procedure for “MFLP-41 Environmental Sampling for the Detection of Microorganisms“.


This document is not a procedure, it is a list of suggested steps being provided to you to facilitate your creating a sampling procedure in accordance with your quality assurance program and policies. Some steps may have been taken from the USDA, FDA, EPA, CDFA, Environmental Canada, CFIA and ISO sampling requirements.
However, it is highly suggested that you refer to the requirements of any certification programs you may participate in and/or contractual requirements that may apply to your operation to ensure that you comply with any specific sampling requirements that they may impose.

  1. Do not open sterile sample bag until you start sampling.
  2. Close the sample bag between each sub-sample in a composite sample.
  3. Change rubber gloves between each sample when taking individual samples.
  4. Environmental samples should be taken under floor mats, in wall or floor cracks, from drains, in areas of peeling paint, under work tables, equipment crevices and so forth.
  5. Samples should be taken just prior to sending them to the lab as analysis should begin within 24 hours of sampling.