Key Takeaways

  • Store chemicals separately from food in original labeled containers
  • Never use food containers for chemicals—even temporarily
  • SDS (Safety Data Sheet) must be readily accessible to all staff
  • Acidic foods can leach toxic metals from improper containers
  • Physical hazards include glass, metal, jewelry, hair, and stones
  • Enforce strict jewelry, hair restraint, and fingernail policies
Last updated: January 2026

2.2 Chemical and Physical Contaminants

While biological hazards cause most foodborne illnesses, chemical and physical contaminants can cause serious injuries and poisonings. These hazards are entirely preventable through proper procedures and awareness.

Chemical Contaminants

Chemical contamination occurs when harmful chemicals get into food. Unlike biological hazards, even tiny amounts of chemicals can cause immediate harm.

Common Chemical Contaminants

Chemical TypeSourcesPrevention
Cleaning ChemicalsSanitizers, degreasers, oven cleaners, detergentsStore separately from food; label all containers; never use food containers for chemicals
PesticidesInsecticides, rodenticidesUse only licensed PCO; never apply in food prep areas; store away from food
Toxic MetalsLead, copper, brass, zinc, antimony, cadmiumUse only food-grade containers; avoid high-acid foods in metal containers; check plumbing
Food AdditivesMSG, sulfites, nitratesUse only approved additives; never exceed legal limits; label for allergen-sensitive guests
LubricantsEquipment oils and greasesUse only food-grade lubricants; prevent dripping onto food

The Danger of Toxic Metals

High-risk scenario: Acidic foods (tomato sauce, citrus, vinegar) can leach metals from containers:

  • Carbonated beverages in copper containers → copper poisoning
  • Tomato sauce in zinc-coated containers → zinc poisoning
  • Acidic punch in lead crystal bowls → lead poisoning
  • Sauerkraut in copper pots → copper contamination

Prevention:

  • Use only stainless steel, food-grade plastic, or glass for acidic foods
  • Never use galvanized metal (zinc-coated) or copper for food storage
  • Inspect plumbing; replace lead pipes in older buildings

Material Safety Data Sheets (MSDS/SDS)

Safety Data Sheet (SDS) - formerly called Material Safety Data Sheet (MSDS) - provides critical information about chemical products.

Required by OSHA (Occupational Safety and Health Administration)

Every SDS must include:

  1. Product identification - Chemical name and manufacturer
  2. Hazard identification - What dangers it presents
  3. Composition/ingredients - What chemicals it contains
  4. First-aid measures - What to do if exposed
  5. Fire-fighting measures - How to handle chemical fires
  6. Accidental release measures - Spill cleanup procedures
  7. Handling and storage - How to use and store safely
  8. Personal protection - Required protective equipment (PPE)

For the Exam: Know that SDS sheets must be readily accessible to all employees during work shifts. They are required by law and must be available in case of emergency.

Preventing Chemical Contamination

Storage Rules:

  • Store chemicals in separate area from food and utensils
  • Keep in original labeled containers (never transfer to food containers)
  • Store below food storage areas (prevent dripping)
  • Keep lids tightly closed

Usage Rules:

  • Never use food containers for chemicals (even temporarily)
  • Follow manufacturer's instructions for dilution
  • Wear required PPE (gloves, goggles)
  • Label all spray bottles and secondary containers
  • Don't spray chemicals near food or food-contact surfaces
  • Allow proper contact time for sanitizers

Training Requirements:

  • Train staff on chemical hazards (using SDS)
  • Show proper dilution, use, and storage
  • Explain what to do in case of exposure
  • Update training when new chemicals introduced

Physical Contaminants

Physical contamination occurs when foreign objects get into food. These can cause choking, broken teeth, cuts, or other injuries.

Common Physical Contaminants

ContaminantSourcesPrevention
GlassBroken light bulbs, broken dishes, glass containersUse shatter-resistant bulbs; inspect glassware before use; don't use glass near prep areas
MetalStaples, metal shavings, can lids, broken equipment, jewelryCheck cans for damage; maintain equipment; no jewelry policy; use can opener properly
Stones/PitsUnwashed produce, fruit pits, bone fragmentsWash all produce thoroughly; inspect foods carefully; warn guests about bones
PlasticPackaging materials, broken utensils, gloves, food wrapRemove packaging from prep area immediately; inspect utensils; replace damaged items
Personal ItemsJewelry, buttons, hair, fingernails, bandagesNo jewelry policy (except plain ring); wear hair restraints; use gloves properly
WoodToothpicks, wood splinters from boxes/palletsDon't use toothpicks in food; inspect wooden equipment; keep pallets away from food

High-Risk Physical Hazards

Jewelry Policy:

  • Not allowed: Rings with stones, bracelets, watches, dangling earrings, necklaces
  • Allowed (typically): Plain wedding band
  • Why: Jewelry can harbor bacteria and fall into food

Hair Restraints:

  • Required: Hair nets, hats, visors, beard restraints
  • Why: Prevents hair from falling into food; reduces hand-to-hair-to-food contamination

Fingernail Policy:

  • Keep short and clean
  • No artificial nails or nail polish (except with intact gloves)
  • Why: Long nails can harbor bacteria; polish and artificial nails can chip into food

Preventing Physical Contamination

Equipment Maintenance:

  • Regularly inspect equipment for wear and damage
  • Replace worn utensils, cutting boards, and containers
  • Use only food-grade equipment (NSF-certified when possible)
  • Keep equipment in good repair

Food Inspection:

  • Visually inspect all food during prep
  • Feel through ground meat for foreign objects
  • Check produce for stems, pits, stones
  • Strain sauces and soups before service

Personal Practices:

  • Enforce strict jewelry and nail policies
  • Require hair restraints for all food handlers
  • Cover wounds with waterproof bandages and gloves
  • Remove personal items from pockets (pens, thermometers)

Facility Design:

  • Install shatter-resistant light bulbs or protective covers
  • Keep maintenance tools away from food areas
  • Remove packaging and boxes from prep areas immediately
  • Use proper trash receptacles with lids
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Chemical and Physical Contamination Prevention
Test Your Knowledge

Which type of food is MOST likely to leach toxic metals from containers?

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Test Your Knowledge

What does SDS stand for, and why is it important?

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D
Test Your Knowledge

What is the correct way to store chemicals in a food establishment?

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B
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D
Test Your Knowledge

Which of the following jewelry items is typically allowed for food handlers?

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D