Hurricane Response Guide for Environmental Public Health Professionals
Pro Tips Must Know Food
The Food and Drug Administration (FDA) conducts three main types of sampling to ensure food safety: 1. Product Sampling: Collecting samples of food products, including finished products, in-process items, and raw ingredients. This helps prevent harmful contaminants from reaching consumers and verifies accurate labeling. It includes microbiological surveillance sampling , gluten-free food product surveillance sampling , and milk allergen sampling . 2. Environmental Sampling : Collecting samples from the environment surrounding the food, usually in production facilities. This helps identify potential sources of contamination that may affect finished products. 3. Emergency Response/Emerging Issues Sampling: Conducting both environmental and product sampling in response to foodborne illness outbreaks or potential food safety issues based on trends or intelligence. This helps identify the source of disease-causing pathogens and aids in gathering information on emerging food safety concerns. Water Large-volume and grab-sampling collection methods include dead-end ultrafiltration (DEUF) from pressurized and non-pressurized sources, as well as grab sampling. The key points are as follows: 1. DEUF from a pressurized source : This method uses the pressure within a piped system to push water through an ultrafilter, without requiring a pump. The inlet pressure is controlled by maintaining a flow rate of <4 liters (L) per minute. For low-turbidity water (<5 Nephelometric Turbidity Unit or NTU), 100 L or more can be filtered. 2. DEUF from a non-pressurized source : This method uses a peristaltic pump to draw water through the ultrafilter. The inlet pressure is controlled by maintaining a flow rate of <4 L per minute. For surface water or high-turbidity water, a maximum of 50 L is recommended. DEUF is effective for wastewater effluent samples and water samples with turbidity values up to 80 NTU. 3. Grab sampling : A 1 L grab sample is collected following standard methods and shipped to a laboratory for direct assay or further concentration and analysis. This method is the simplest but may limit the ability to capture microorganisms present at low concentrations. Sampling methods can be modified based on water source, specific site conditions, or equipment limitations. If ultrafiltration cannot be performed in the field or if contaminants are suspected to be smaller than 20 nanometer (nm) or 30,000 Daltons (Da), grab samples can be collected and transported to the laboratory for concentration and analysis.
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