Overview

The Ministry of Agriculture, Food and Rural Affairs (OMAFRA) administers an annual environmental monitoring program at non-federally licensed dairy and foods of plant origin facilities across the province.

The purpose is to monitor and detect the presence of Listeria. The presence of Listeria in processing facilities raises concerns about the safety of food products processed.

Environmental monitoring involves the collection of swabs from food contact and non-food contact surfaces within these facilities.

The swabs are analyzed at the University of Guelph Agriculture and Food Laboratory for the presence of Listeria species (spp.).

Results from this program are used to help:

  • identify gaps in the facility’s cleaning and sanitation programs
  • mitigate potential food safety risks

Importance of environmental monitoring

Listeria has several unique growth characteristics that allow it to thrive in food processing facilities. Detection of Listeria is a way of identifying gaps in a facility’s cleaning and sanitizing processes which may have failed to remove biological contaminants such as pathogenic bacteria.

The presence of contaminants can put the safety of that facility’s products at risk. These risks may be compounded by poor employee practices, such as improper handwashing, which can transfer contamination to other surfaces and products (cross contamination).

To produce safe products, operators must ensure that their cleaning and sanitation programs are adequate and promptly address any identified concerns with their cleaning and sanitation practices.

Environmental monitoring is a valuable tool to help identify these concerns before they lead to product contamination.

Swab collection process

Authority to collect environmental swabs

OMAFRA’s food safety inspectors have authority under their respective legislation, the Food Safety and Quality Act, 2001 and the Milk Act to inspect the facilities they regulate.

This can involve the collection of environmental swabs to help identify areas in the plant that may be unclean and could expose food products to contamination.

If your facility does not fall under OMAFRA’s regulatory jurisdiction (for example, areas of your facility that process sheep milk or minimally process produce) you are still encouraged to participate in OMAFRA’s Environmental Monitoring Program as it provides valuable and important information about your cleaning and sanitizing program that can help you produce safe food.

Timing of swab collection

Food Safety Inspectors contact facility operators directly, to arrange an appropriate day and time to complete the environmental swabbing for the presence of Listeria species (spp.).

At each visit, swabs are collected from both food contact and non-food contact surfaces.

Ideally, the swabs are collected 2 to 3 hours after startup to allow time for any Listeria present on the equipment or surfaces to dislodge and be picked up by the swab. This timing also provides opportunity for any Listeria present on the surfaces to grow and multiply to a detectable level before swab collection.

If your facility’s production time is less than three hours, the food safety inspector may arrange an alternate time to collect the swabs.

Produce grown in soil

When collecting swabs from facilities that pack produce grown in soil, food safety inspectors may choose to collect the swabs prior to operation, to ensure the facility is clean before production begins.

Swab collection locations

To collect a swab, food safety inspectors will rub sterile sponges (swabs) on select surfaces to pick up any bacteria that may be present.

The swabs are:

  • individually sealed inside sterile plastic bags
  • assigned unique sample identification numbers
  • sent to the laboratory where they are analyzed for the presence of Listeria (spp.)

During routine swabbing, inspectors will collect approximately 10 environmental swabs. They may, at their discretion, collect several more or fewer as circumstances require.

Approximately half of the swabs are collected from food contact surfaces; the remaining swabs are collected from adjacent and surrounding non-food contact surfaces.

While collecting swabs, food safety inspectors will make efforts to minimize the impact on the facility’s operations. Operators may need to temporarily adjust their operations and/or disassemble some equipment to allow the food safety inspector access to the desired surface.

Swab collection and shipping

All samples are packaged and transported to the laboratory according to established protocols. These protocols help maintain:

  • the samples’ integrity (including temperature control)
  • chain-of-custody until their arrival at the laboratory for analysis

The names of the facilities that are swabbed for OMAFRA’s Environmental Monitoring Program are known only to OMAFRA staff and are not shared with the laboratory.

Laboratory results

All environmental swabs are analyzed for the presence of Listeria species (spp.). The presence of Listeria (spp.) on a surface indicates inadequate cleaning and sanitation and is an early warning to signal the potential presence of Listeria monocytogenes (L. monocytogenes).

L. monocytogenes is a Listeria species that is harmful to human health and can cause listeriosis, leading to severe illness or even death in vulnerable populations.

Swabbing for the presence of Listeria (spp.) is a valuable and cost-effective tool that helps to prevent contamination of food products with L. monocytogenes.

A swab that tests positive for Listeria (spp.) tells the operator that there is potential contamination in the facility and provides the opportunity for it to be mitigated before the food product is contaminated.

Laboratory results are reported to OMAFRA 3 to 5 business days after the swabs arrive at the laboratory. Food safety inspectors will review these results and contact the operator to inform them and discuss next steps.

Follow-up actions for positive swabs

If a swab tests positive for Listeria (spp.), food safety inspectors will follow-up with the facility to help identify the cause and the corrective actions required.

Prompt corrective action helps to ensure that any Listeria in the facility is eliminated and any gaps in cleaning and sanitizing and or production practices are identified and corrected before food products become contaminated.

OMAFRA staff may follow up by:

  • reviewing of cleaning/sanitation practices
  • providing education and advice to the operator
  • collecting additional swabs
  • issuing verbal and/or written warnings
  • issuing compliance orders

Contact us

For more information about OMAFRA’s Environmental Monitoring Program, call the Agricultural Information Contact Centre at 1-877-424-1300 or email: