Overview
Vibrio parahaemolyticus (Vp) is a very temperature dependent bacterium. The National Shellfish Sanitation Program (NSSP) requires DOH to have a Vp control plan. The Vp Control Plan is in WAC 246-282-006 and was last updated in January 2026.
Revisions to the plan focus on encouraging best management practices, reducing opportunities for Vp growth after harvest, and restricting harvest when environmental conditions are ideal for growth.
DOH offers Vp training throughout the year. Training dates can be found here: Commercial Shellfish Training.
Frequently Asked Questions
Who does this control plan apply to?
All harvesters and shellfish dealers harvesting, buying from a harvester, or selling shellstock oysters from May 1 through September 30.
What are the annual harvest plan requirements?
All harvesters and dealers intending to harvest or be an original dealer of shellstock oysters from May through September must have an approved Vp harvest plan.
Harvest plans must be submitted to the Department at least 2 weeks before first planned harvest for approval. The Department will review and respond within 14 days of receiving harvest plans.
Provided the plan is approved and no changes are made, operations need to keep the plan on file, sign, and date it annually.
What risk category is my growing area in?
Find your growing area risk category. This list will be updated and posted by February 1 each year.
Based on the risk category, what is the time to cooling (or 50°F) for my growing area?
See the time to cooling and risk categories.
What are some of the important dates to remember?
February 1: Risk categories announced by the Department of Health.
May 1: Control plan months begin.
October 1: Control plan months end.
January 14: Deadline for shellfish dealers to report oyster production data to the Department of Health.
Forms and Materials
Harvest Plan (Word)
All harvesters and shellfish dealers intending to harvest or sell shellstock oysters from May through September must submit this document to the Department of Health for approval.
Harvest Temperature Record, HA (PDF)
Sample document for harvester licensees to record harvest temperatures. Adapt this form to fit your harvesting operation. For example, if you do not initiate cooling, remove those columns. If you only harvest from one harvest site, include the growing area and risk category in the header so you don't have to enter the growing area name and risk category number with each entry.
Harvest Temperature Receiving Record, SS/SP (PDF)
Sample document for dealer licensees to record harvesting and receiving temperatures. Adapt this form to fit your harvesting or receiving operation.
Thermometer Verification Log, HA (PDF)
Sample document for harvester licensees to record thermometer verification.
Thermometer Verification Log, SS/SP (PDF)
Sample document for dealer licensees to record thermometer verification.
Transfer Record Guidance, HA (PDF)
Information harvesters must provide the initial dealer when transferring shellstock oysters during the control plan months. This information can appear on the invoice as in the sample document if the invoice travels with the oysters. If the invoice is sent later, than this information should be included in the trip ticket, bill of lading, or other document that accompanies the oysters.
Oyster Production Reporting
Online form for shellfish dealers to collect and report oyster production data. Reports are due annually by December 31.
Time to Cooling and Harvest Restrictions
Risk Category 1
|
Condition at Harvest |
Time of Harvest |
|---|---|
| Except as noted below, the time of harvest to cooling is: | 9 hours |
| When ambient air temperature at harvest is greater than 90 degrees F: | 7 hours |
| When harvest temperature is between 68 degrees F and 70 degrees F: | 5 hours |
| When harvest temperature is above 70 degrees F: | Harvest is not allowed for 24 hours |
Risk Category 2
|
Condition at Harvest |
Time of Harvest |
|---|---|
| Except as noted below, the time of harvest to cooling requirement is: | 7 hours |
| When ambient air temperature at harvest is greater than 85 degrees F: | 5 hours |
| When harvest temperature is between 66 degrees F and 68 degrees F: | 3 hours |
| When harvest temperature is above 68 degrees F: | Harvest is not allowed for 24 hours |
Risk Category 3
|
Condition at Harvest |
Time of Harvest |
|---|---|
| Except as noted below, the time of harvest to cooling is: | 5 hours |
| When ambient air temperature at harvest is greater than 80 degrees F: | 3 hours |
| When harvest temperature is between 64 degrees F and 66 degrees F: | 1 hour |
| When harvest temperature is above 66 degrees F: | Harvest is not allowed for 24 hours |