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Ready-to-Eat Sanitation 

This document has been created to be used for reference purposes only. The 

information in this document is not all-inclusive. Please refer to the FSIS directives and 

notices for detailed policy and procedural information. 

Many RTE processes involve handling the product after it has been subjected to an initial 

lethality treatment, an event we refer to as post-lethality exposure. When product is directly 

exposed to the environment, it can become cross-contaminated. Cross-contamination is the 

transfer of bacteria, possibly including pathogenic bacteria, to the exposed RTE product 

after the lethality treatment. These bacteria can come from the environment, from employees, 

or from equipment. They can be transferred directly, such as when an exposed RTE product is 

placed on a tabletop that has bacteria on it. Often, they are transferred indirectly, such as when 

a pallet placed on the floor in a raw area is subsequently used in the RTE area, or when an 

employee handles a pallet and then touches exposed product. 

RTE establishments are responsible for producing product that is free from pathogens. 

The pathogen Listeria monocytogenes (Lm), one species of Listeria bacteria, is of particular 

concern because it has potentially fatal consequences. Lm is a biological food safety hazard 

that an establishment producing post-lethality exposed RTE products must control through its 

HACCP plan or prevent in the processing environment through Sanitation SOPs or some other 

prerequisite program. RTE product is considered adulterated if it contains Lm or if it comes into 

direct contact with a food contact surface that is contaminated with Lm. 

Lm is spread very easily by direct contact with a contaminated surface. Lm can survive and 

grow in cool, damp environments, such as those found in processing areas, coolers, or 

floors. Incomplete removal of product debris can provide nutrients and a place of attachment 

which allows bacterial growth. Additionally, if not removed by cleaning and sanitizing, Lm 

colonies can secrete a biofilm, a thick, protective matrix that is resistant to subsequent 

application of sanitizers. Biofilms can form on solid surfaces, such as stainless steel and 

rubber, and can survive adverse conditions on apparently smooth surfaces. 

Since Lm thrives in damp environments, establishments need to keep equipment dry to reduce 

its growth. In the course, we discussed a generic sequence that establishments should follow 

when conduct pre-operational sanitation procedures. (Note that establishments may vary 

their procedures from this model to suit their layout, equipment, and processes): 

• Dry cleaning of equipment 

• Wash and rinse floor 

• Pre-rinse equipment 

• Clean, foam, and scrub equipment 

• Rinse equipment 

• Visually inspect equipment 

• Sanitize floor and then equipment 

• Dry 

**Note that the floor is generally cleaned and sanitized before the equipment. This is to 

ensure that bacteria on the floor are not aerosolized during spray-down and subsequently 

land on clean equipment.** 

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While it is not required, it is good practice for establishments to rotate their sanitizers to keep 

pathogens and other microorganisms “off-balance”. Rotating between acidic and alkaline 

detergents is a good way to prevent pathogens from developing resistance to sanitizer 

chemicals. Chlorine (e.g., bleach), peroxyacetic acid (PAA), and quaternary ammonium (“quat”) 

compounds are examples of different sanitizers establishments may use over the course of 

time. 

We have already discussed SSOPs, but establishments’ compliance with the Sanitation 

Performance Standards (SPS) is essential to prevent the creation of environmental reservoirs of 

Lm and other pathogens. Establishments should consider the following: 

(1) Air flow – Establishments producing RTE product in a post-lethality environment should 

consider that pathogens like Lm may travel on air currents. Therefore, facilities should 

be designed so that air does not readily flow from “dirty” areas into the post-lethality 

processing area. 

(2) Ventilation – Related to air flow, establishments should consider designing ventilation 

systems to bring clean or purified air into post-lethality processing areas and to readily 

draw objectionable vapors which may contain contaminants out. Some establishments 

use positive-pressure ventilation, in which purified air is pumped into post-lethality 

processing areas at slightly higher than atmospheric pressure and then flows down a 

pressure gradient to other areas of the establishment. 

(3) Layout – Establishments should design their facilities so that it is difficult—if not 

impossible—for personnel and equipment to readily move from raw processing areas 

into RTE processing areas. 

One of the environmental aspects addressed should be dust generated by construction and 

other disruptive activities, which can establish contamination on food contact and other 

environmental surfaces. Removal of walls, ceilings, drains, etc. can release Lm into the air, 

which can subsequently be carried on air currents to RTE processing areas. 

Though we discuss sampling in another module, we should address how we use sampling to 

assess sanitation effectiveness. FSIS’s RTE sampling program confirms establishment 

controls are effective and measures the effectiveness of sanitation procedures. 

In addition to the sampling programs, IPP verify that establishments: 

• Monitor implementation of their SSOPs 

• Observe employee hygiene practices 

• Maintain good recordkeeping 

• Reevaluate and modify SSOPs as needed 

Establishments may develop sampling programs for one or more of the following purposes: 

• Measuring the effectiveness of cleaning and sanitation 

• Verifying that finished product is free of Lm 

• Testing for organic residues, spoilage organisms (including yeast and mold), coliform 

bacteria, non-pathogenic bacteria, or indicator organisms such as Listeria spp. 

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There are a variety of test types and sampling methods that establishments may use, such 

as swabs and sponges used with standard plating methods, prepared plates and other testing 

kits of various types, and air collection systems. Establishments may also utilize total plate 

counts (TPC) or ATP bioluminescence testing. The amount of time it takes test results to be 

available also varies from several minutes to several days, depending on the type of method 

used. 

Establishments may test: 

(1) Environmental surfaces – Areas where product does not make direct contact, such as 

walls, ceilings, floors, table or cart legs, employee shoes, cables, or light switches. Such 

testing yields information about sources of pathogens, extent of contamination, 

information about equipment design, and identifies possible cross-contamination sites. A 

positive test indicates that a pathogen may have been transferred to product and should 

be followed up by cleaning and further testing of food contact surfaces and product. 

(2) Food contact surfaces – Surfaces which may directly contact finished product, such as 

tabletops, conveyor belts, gloves, aprons, hands, knives, packaging material, and brine 

solutions. A positive result when testing for an indicator organism (e.g., Listeria spp.) 

indicates that product may have been contaminated. A positive result for Listeria 

monocytogenes indicates that product has been adulterated. 

(3) Product – Establishments may test actual product after it has undergone the lethality 

step, thus assessing the effectiveness of the lethality treatment(s) applied. A positive 

result for Lm indicates that the product has been adulterated and supports the idea that 

Lm must be considered as an RLTO hazard. 

In all cases, it is essential that the establishment maintain comprehensive records of sampling 

results. 

Finally, remember the important connection between sanitation and HACCP systems in RTE 

processing establishments. In most cases, the lethality step is established as a critical control 

point (CCP); however, establishments may also need to develop one or more CCPs to address 

the risk of post-lethality contamination (exposure), or to address deficiencies not covered by the 

sanitation program. 

RTE/SS Self-Paced Inspection Course