How We Grade Restaurants

Rodents contaminate food and surfaces with urine, droppings, and hair. They carry Salmonella and pathogenic E. coli that can cause severe food poisoning.

Mice and rats shed pathogens continuously through urine and feces. A single mouse produces 40-100 droppings per day. Rodent contamination of food preparation areas creates direct pathways for Salmonella and pathogenic E. coli to reach ready-to-eat food. CDC outbreak investigations frequently identify rodent activity as a contributing factor in restaurant-associated illness. The FDA Food Code classifies active rodent evidence as an imminent health hazard requiring immediate correction.

Cockroaches crawl through drains, sewage, and waste then walk on food and prep surfaces, mechanically transferring bacteria like Salmonella and E. coli.

Cockroaches are documented mechanical vectors for over 30 species of bacteria. They travel between unsanitary areas (drains, garbage, sewage) and food contact surfaces, depositing pathogens as they move. Their shed skins and feces also contain potent allergens that can contaminate food. While less directly dangerous than rodents (which urinate on food), cockroach presence indicates systemic sanitation failure and creates persistent contamination pathways.

Flies land on garbage and feces then land on food, transferring bacteria like Shigella and Salmonella. However, the direct risk from occasional fly presence is lower than other pest issues.

House flies and fruit flies can carry Shigella, Salmonella, and E. coli on their legs and bodies. Flies regurgitate digestive enzymes onto food surfaces before feeding, creating a direct contamination pathway. However, the dose typically transferred by incidental fly contact is lower than contamination from rodent droppings or cockroach activity. The risk escalates significantly if flies are landing directly on exposed food. Fruit flies in particular indicate decaying organic matter that may harbor bacteria.

Food held above 41°F enters the 'danger zone' where bacteria multiply rapidly. Listeria can grow even under refrigeration — above 41°F, growth accelerates dangerously. This is one of the most common causes of foodborne outbreaks.

The FDA Food Code requires cold holding at 41°F (5°C) or below. Above this temperature, pathogens like Salmonella double every 20-40 minutes. Listeria monocytogenes is especially dangerous because it grows at refrigeration temperatures — even small increases above 41°F dramatically accelerate its growth. CDC's 2014-2022 outbreak analysis identifies temperature abuse as one of the top three contributing factors in foodborne illness outbreaks. Listeria causes approximately 1,250 serious infections and 172 deaths annually in the US — the third leading cause of death from food poisoning.

Food held below 135°F allows dangerous bacteria to multiply and produce toxins that can't be destroyed by reheating. Clostridium perfringens alone causes nearly 1 million illnesses per year in the US.

The FDA Food Code requires hot holding at 135°F (57°C) or above. When cooked food drops below this temperature, spore-forming bacteria like C. perfringens and B. cereus can germinate and multiply rapidly. C. perfringens is the second most common cause of foodborne illness in the US with ~966,000 cases/year. S. aureus produces heat-stable toxins — once formed, reheating cannot make the food safe. CDC data shows that improper hot holding is a leading contributing factor in restaurant outbreaks.

When cooked food is stored near raw meat, juices from raw meat can drip onto ready-to-eat food. Since the cooked food won't be heated again, any bacteria transferred will be eaten alive.

Cross-contamination from raw to ready-to-eat food is one of the most dangerous pathways because there is no subsequent kill step. Raw poultry commonly carries Salmonella (present in ~25% of raw chicken) and Campylobacter. Raw ground beef can harbor STEC (Shiga toxin-producing E. coli). The FDA Food Code requires raw animal foods to be stored below ready-to-eat foods and separated by type. CDC outbreak investigations consistently identify raw-to-ready-to-eat cross-contamination as a primary contributing factor.

Without proper date marking, ready-to-eat food can be kept too long under refrigeration. Listeria — which kills about 1 in 5 people it seriously infects — grows slowly even in the fridge and reaches dangerous levels after 7 days.

The FDA Food Code's 7-day date marking rule (§3-501.17) exists specifically to control Listeria monocytogenes. Unlike most bacteria, Listeria grows at refrigeration temperatures (albeit slowly). After 7 days at 41°F, Listeria populations can reach infectious doses. Listeria has a 20-30% fatality rate among high-risk groups (pregnant women, elderly, immunocompromised). Without date marking, staff have no way to know when food should be discarded, creating a silent but deadly hazard.

Adulterated food is unsafe by definition — it may contain pathogens, toxins, foreign objects, or unapproved chemicals. Serving adulterated food is the most direct path to making someone seriously ill.

Food is 'adulterated' under federal and state law when it contains any poisonous or deleterious substance, has been prepared or held under unsanitary conditions whereby it may have been contaminated, or is otherwise unfit for food. This is the highest-risk finding because it means the food itself is already compromised. The specific hazard depends on the type of adulteration but can include bacterial pathogens, chemical contamination, allergens, or physical hazards. FDA considers adulterated food an imminent health hazard.

Decomposed or putrid food contains extremely high levels of bacteria and toxins. It is visibly unsafe and should never be anywhere near a kitchen — let alone served to customers.

Food that is filthy, putrid, or decomposed has undergone extensive microbial degradation. Bacterial counts in decomposed food can exceed billions per gram — far above infectious doses for most pathogens. Decomposition also produces biogenic amines (histamine, tyramine) and bacterial toxins that cause illness even if the food is subsequently cooked. The presence of such food in a kitchen also indicates severe failure of basic food safety management — receiving, rotation, and storage controls have all broken down.

Unwashed hands are the #1 way restaurant workers spread Norovirus — which causes half of all food poisoning outbreaks. An infected worker can carry billions of virus particles; it only takes a few to make you sick.

CDC research found that food workers wash their hands when they should only about 1 in 3 times. Norovirus — the leading cause of foodborne illness outbreaks — is primarily spread by infected food handlers who don't wash their hands after using the restroom. An infected person sheds billions of norovirus particles, and the infectious dose is as low as 18 particles. Hepatitis A, Shigella, and Salmonella are also commonly transmitted through the fecal-oral route via unwashed hands. CDC's outbreak analysis consistently identifies 'infectious food workers' as one of the top three contributing factors.

If there's no hand-washing station, NO ONE on staff can wash their hands properly. This is worse than a single employee skipping — it's a system failure that affects every food handler for every shift.

The absence of an accessible, properly equipped hand-washing station is rated higher than a single handwashing failure because it represents a systemic failure. Without a hand sink with soap, warm water, and paper towels within reach of food preparation areas, no employee can practice proper hand hygiene regardless of their training or intent. The FDA Food Code (§6-301.11) requires hand-washing facilities specifically because handwashing is the single most important intervention against norovirus, hepatitis A, and bacterial transmission. This violation means the entire operation is running without its primary defense against fecal-oral pathogen transmission.

Cross contamination transfers dangerous bacteria from raw meat, dirty surfaces, or contaminated items to food that's ready to eat. Since that food won't be cooked again, any bacteria transferred will be consumed.

Cross-contamination is repeatedly identified by the CDC as a primary contributing factor in foodborne illness outbreaks. It can occur through direct contact (raw meat juices dripping onto produce), indirect contact (shared cutting boards, utensils), or through food handlers. The critical danger is when pathogens reach ready-to-eat food that will have no subsequent kill step. Salmonella, Campylobacter, and Shiga toxin-producing E. coli are the most common bacterial causes of outbreak-associated illness from cross-contamination. Allergen cross-contact is also a serious concern — undeclared allergens cause approximately 30,000 ER visits per year.

Raw meat, poultry, and seafood carry dangerous bacteria. When they aren't separated from other foods, bacteria can transfer to items that will be eaten without further cooking.

The FDA Food Code (§3-302.11) requires raw animal foods to be separated from ready-to-eat foods and from each other during storage, preparation, holding, and display. Raw poultry must be stored below all other foods because it most commonly carries Salmonella and Campylobacter. Failure to separate allows drip contamination and surface cross-contact. This violation is scored slightly lower than active cross-contamination (#12) because it represents a storage/separation failure that creates risk potential rather than confirmed contamination, but the underlying hazard pathway is the same.

Cleaning removes visible dirt, but only sanitizing kills the invisible bacteria and viruses that cause food poisoning. Without sanitizer, surfaces that look clean can still spread Norovirus, Salmonella, and Listeria.

The FDA Food Code (§4-702.11) requires sanitization of food-contact surfaces after cleaning. Cleaning with soap and water removes food residue and some bacteria, but it does not reliably eliminate pathogens. Norovirus in particular is highly resistant to many common cleaners — it survives on surfaces for days and requires proper sanitizer concentration to inactivate. Listeria forms biofilms on food-contact surfaces that resist cleaning without sanitization. Without sanitizer use, surfaces become persistent reservoirs for pathogen transmission between food batches.

The 3-compartment sink process (wash, rinse, sanitize) is designed to eliminate bacteria from utensils and equipment. Skipping steps or doing them out of order means utensils may look clean but still carry infectious organisms.

The 3-compartment sink sequence — wash in detergent, rinse in clean water, sanitize at proper concentration — is the FDA Food Code's (§4-603.16) prescribed method for manual warewashing. Each step serves a specific purpose: detergent removes food residue and grease, rinsing removes detergent (which can inactivate sanitizer), and sanitizing kills remaining pathogens. When steps are skipped or performed incorrectly, utensils and food-contact equipment become vehicles for pathogen transmission. This is especially critical for items that contact ready-to-eat foods.

Cleaning chemicals, pesticides, and degreasers stored near food or food-contact surfaces can spill, leak, or produce fumes that contaminate food. Chemical poisoning from contaminated food can cause severe burns, organ damage, and death.

The FDA Food Code (§7-201.11) requires poisonous or toxic materials to be stored so they cannot contaminate food, equipment, or single-service articles. Chemical contamination of food — while less frequent than bacterial illness — can cause acute poisoning with severe consequences including chemical burns to the mouth, throat, and digestive tract, organ damage, and in extreme cases, death. Common restaurant chemicals (concentrated bleach, oven cleaners, degreasers, pesticides) are all capable of causing serious harm if they contact food through spills, leaks, or aerosolization.

Sanitizer that's too weak won't kill bacteria and viruses. Sanitizer that's too strong can leave chemical residues on dishes and utensils that cause illness. Either way, the safety system has failed.

The FDA Food Code (§4-501.114) requires chlorine sanitizer concentration between 50-200 ppm for effective pathogen elimination. Below 50 ppm, sanitizer fails to achieve the required reduction in pathogens — norovirus and Salmonella can survive and transfer to the next food item that contacts the surface. Above 200 ppm, residual chlorine on food-contact surfaces can cause chemical irritation and off-flavors. Proper concentration monitoring is a critical control point because sanitizer effectiveness is concentration-dependent — half the concentration does NOT provide half the protection.

Like chlorine, quaternary ammonium sanitizer must be at the right concentration. Too low and it won't kill pathogens on your dishes. Too high and chemical residues can contaminate food.

Quaternary ammonium compounds (quats) are the other major category of food-contact surface sanitizer. The FDA Food Code (§4-501.114) requires quat concentration of 150-400 ppm depending on the product. The same principles as chlorine apply: sub-effective concentrations leave pathogens alive on surfaces, while excessive concentrations leave chemical residues. Quats have an additional complication — they are inactivated by organic matter and certain detergents, meaning they can test at proper concentration in clean water but fail to sanitize dirty surfaces.

Louisiana requires that crawfish and shrimp sold in restaurants come from approved, traceable sources. Imported product without proper documentation can't be verified as safe — it may have been processed under unknown safety standards.

Louisiana has specific regulations requiring crawfish and shrimp to be from approved sources with proper documentation (LDH retail food guidance). This is primarily a traceability and source-control violation rather than an immediate contamination issue. The risk is indirect: without verified sourcing, there is no assurance that the product was harvested, processed, and transported under safe conditions. If the product is actually from an unapproved or uninspected source, the risk would be much higher and should be scored under 'adulterated food' instead.

Sewage is human and animal waste — it contains virtually every type of foodborne pathogen. Sewage contamination in a restaurant is an imminent health hazard that can simultaneously expose patrons to Norovirus, Hepatitis A, Salmonella, and parasites.

Sewage contamination represents the most direct fecal-oral transmission pathway possible in a food establishment. Raw sewage contains Norovirus (the #1 cause of foodborne outbreaks), Hepatitis A (which can cause liver failure), Shigella, Salmonella, pathogenic E. coli, Cryptosporidium, and Giardia — often simultaneously. The FDA Food Code (§5-403.11) classifies sewage backup into a food establishment as an imminent health hazard requiring immediate closure. Even trace sewage contamination of food preparation areas creates unacceptable risk because many of these pathogens have extremely low infectious doses.

When food spends too long in the temperature 'danger zone' (41°F-135°F), bacteria can multiply to dangerous levels in hours. Some bacteria produce toxins during this time that survive reheating — the damage is done even if you cook it again.

Time/temperature control is the cornerstone of food safety in the FDA Food Code. Bacteria double every 20-40 minutes in the danger zone (41-135°F). The 4-hour maximum cumulative exposure limit exists because pathogen populations can reach infectious doses within this window. CDC's analysis of outbreaks from 2014-2022 found that prolonged time in the danger zone — during preparation, cooking, cooling, and holding — was among the most frequently identified contributing factors. C. perfringens alone causes ~966,000 illnesses/year, primarily from improper cooling and holding of cooked foods.

Medications and first-aid supplies stored near food can contaminate it with drugs, ointments, or chemicals. While accidental pharmaceutical contamination of food is rare, the consequences can be unpredictable and harmful.

The FDA Food Code (§7-201.11) requires that medicines and first-aid supplies be stored separately from food, equipment, utensils, and single-service articles. The primary hazard is accidental contamination — a broken bottle of medication, a spilled tube of antibiotic ointment, or first-aid chemicals dripping onto food or food-contact surfaces. While this type of contamination is less common than biological hazards, it is entirely preventable through proper storage. The risk is indirect but unnecessary, and the fix is simple — designate a separate, labeled storage area.

Unlabeled chemical containers are a recipe for accidental poisoning. When a bottle of concentrated bleach or degreaser isn't labeled, it can easily be mistaken for water, cooking oil, or another ingredient.

The FDA Food Code (§7-102.11) requires working containers of chemicals to be clearly labeled with the common name of the contents. Unlabeled containers create a direct pathway for accidental chemical contamination of food or beverages. Real-world incidents include staff mistaking unlabeled bleach for water, using cleaning concentrate instead of cooking oil, and adding degreaser to food preparation. These incidents can cause chemical burns to the mouth and digestive tract, organ damage, and hospitalization. The hazard is rated moderate because it requires an additional failure (misidentification) to cause harm, but when that failure occurs, consequences are severe.

Loose rodent bait can contaminate food and food-contact surfaces with pesticide. If bait isn't in a tamper-resistant station, it can be scattered by rodents, kicked by staff, or fall into food preparation areas.

Rodent bait stations must be tamper-resistant and properly secured (FDA Food Code §7-206.13) to prevent the pesticide from contaminating food, equipment, or food-contact surfaces. Loose bait — whether bait blocks, pellets, or powder — can be dragged by rodents into food storage areas, scattered across floors during pest activity, or accidentally kicked into food preparation zones. Rodenticides are toxic to humans and can cause internal bleeding (anticoagulant baits) or organ failure. The violation also indicates poor pest management — if bait is needed, pests are present, and if it's not contained, the pest management program itself is a hazard.

Employee beverages in food preparation areas create contamination risk through spills and through hand-to-mouth-to-food contact. An infected employee's drink can become a transmission vehicle.

The FDA Food Code (§2-401.11) restricts employee eating, drinking, and tobacco use to designated areas away from food preparation, service, and warewashing. The primary risk pathway is hand contamination — touching the mouth area to drink, then touching food or food-contact surfaces without rewashing hands. For a norovirus-positive employee, saliva and oral secretions on a drink container can transfer virus to hands and then to food. Spills from employee beverages can also directly contaminate food or food-contact surfaces. The risk is lower than outright handwashing failure but follows the same pathogen pathway.

Faulty drainage systems can cause sewage to back up into food preparation areas or create cross-connections between waste lines and clean water. A drainage failure in the wrong place can turn into a sewage contamination event.

Drainage system violations include direct connections between waste lines and food preparation sinks, inadequate floor drainage leading to standing waste water, and improperly installed or maintained drain lines that can back up. The FDA Food Code (§5-402.11) requires indirect waste connections specifically to prevent backflow of sewage into food preparation areas. If a drainage failure results in actual sewage backup, it should be scored as sewage contamination (HRS 10). The HRS 6 rating reflects the structural risk — the system is compromised and one additional failure away from direct sewage contamination.