An environmental monitoring program, an EMP, swabs the plant on a schedule to find Listeria, or an indicator for it, before it finds the food. It's built around four zones: zone 1 is food-contact surfaces, zone 2 is right next to them, zone 3 is the rest of the processing room, drains and floors, and zone 4 is outside it. Most swabs go to zones 2 and 3, where a positive is a warning; a positive in zone 1 means the product made since the last clean swab is held. FDA's preventive controls rule calls for environmental monitoring when a ready-to-eat food is exposed to the plant after its last kill step and an environmental pathogen is a hazard. In the example below, an ice cream maker's drain swab comes back positive one week and negative three times after. Below are the zones, the sites, what each result means, the month, and a free workbook.
The short version
- Swab on a schedule to find Listeria or an indicator before it reaches food.
- Zone 1: food-contact surfaces. Zone 2: next to them. Zone 3: the rest of the room. Zone 4: outside it.
- Swab most in zones 2 and 3; drains, floors, frames and wheels are where Listeria settles.
- A positive in zones 2 to 4: clean, re-swab around it, and find the source.
- A positive in zone 1: hold the product made since the last negative and test it.
- FDA's rule calls for an EMP when ready-to-eat food is exposed after its last kill step.
- TaroStack keeps swab results on batch records and holds a lot in one step. More below.
The rules behind it
Verification of preventive controls includes environmental monitoring, for an environmental pathogen or an appropriate indicator, if contamination of a ready-to-eat food with an environmental pathogen is a hazard requiring a preventive control (21 CFR 117.165(a)(3)). The cleaning and sanitizing the EMP checks are sanitation controls (21 CFR 117.135(c)(3)). An ice cream plant, a deli salad kitchen, a cheese room or a cold brew line fits; a bakery whose bread is baked in its package doesn't need one for that product. Where an EMP sits in a food safety plan is in what is a food safety plan. This is general information, not legal advice.
The zones
| Zone | Where | Examples | A positive means |
|---|---|---|---|
| 1 | Food-contact surfaces | Freezer dasher and barrel, filler nozzle, scoops | Hold product made since the last negative; test it; find the source |
| 2 | Next to food-contact surfaces | Equipment frames, control panels, table legs | Clean, re-swab, check zone 1 nearby |
| 3 | The rest of the processing room | Drains, floors, door gaskets, carts | Clean, re-swab around it, find the source |
| 4 | Outside the processing room | Hallways, dish room, locker room | Clean; check traffic into the room |
An example: an ice cream maker's sites
Ironwood Pint Co., a made-up ice cream maker in Birmingham, Alabama, I use in these examples, swabs nine sites:
| Site | Zone | How often |
|---|---|---|
| Batch freezer dasher and barrel, after cleaning | 1 | Monthly |
| Pint filler nozzle | 1 | Monthly |
| Batch freezer frame and control panel | 2 | Weekly |
| Filler table legs and underside | 2 | Weekly |
| Floor drain by the freezer | 3 | Weekly |
| Floor under the filler | 3 | Weekly |
| Walk-in freezer door gasket | 3 | Weekly |
| Hallway floor to the dish room | 4 | Monthly |
| Mop sink | 4 | Monthly |
On October 12 the drain by the batch freezer came back positive for Listeria species. The drain was cleaned and sanitized, three swabs were taken around it, and the drain was swabbed daily for three days: all negative. The frame next to it, zone 2, stayed negative, so nothing pointed toward the food-contact surfaces, and on October 19 the drain went back to weekly. The plan behind the swabs, where Listeria is handled by sanitation rather than a critical control point, is in the ice cream maker's HACCP plan; temperature logs for its freezers are in temperature log template.
Get the workbook
Download the environmental monitoring program template. Two sheets: sites, each swab site with its zone, test and how often; and results, each swab with its date, site, zone and result, a positive in red with its follow-up and re-swab, and each zone's swabs and positives tallied. It's an ordinary Excel file with no macros, and it works in Google Sheets, LibreOffice and Numbers.
Where this stops working
A zone 1 positive turns a swab log into a product question: which pints were filled since the last negative, which lots they're in, and which grocers have them. A results sheet can't answer that, and the answer is needed the same day.
How TaroStack does it
TaroStack keeps swab results on batch records and holds a lot in one step.
Swabs on the batch record. Fields of your own on the batch record, choices and initials, record the zone 1 swab for the day's run and the cleaning check before it, and printable batch-record forms carry them for the kitchen. Cleaning records sit alongside; a cleaning log is in cleaning log template.
Hold in one step. A lot on hold is kept out of what can be sold, so the pints filled since the last negative wait for test results instead of going out on the truck.
Lots to grocers. Each order records the lots each customer got as it ships, so one recall report shows which grocers have pints from a lot, and what's still in your freezers.
| The job | Swab log | In TaroStack |
|---|---|---|
| Zone 1 result for a day's run | A lab sheet | A field on the batch record |
| Holding product after a positive | Tags on the pallets | A hold on the lot |
| Which grocers got that lot | Search the invoices | One recall report |
Batches, batch records with fields of your own, holds and recalls are on every plan, from $49 a month. The first 30 days are free, with no credit card. If you'd like a hand setting up, ask, and we'll do it with you.