04 Oct Cross-Contamination

Cross-Contamination

Cross-contamination occurs when hazardous substances are unintentionally transferred from a contaminated work area to clean areas, vehicles, clothing, personal belongings, or workers’ homes. Contaminants can be carried on hands, skin, clothing, footwear, tools, equipment, and personal protective equipment (PPE).

Without proper controls, workers can expose themselves, coworkers, and family members to hazardous substances long after the original work has ended.

How Cross-Contamination Occurs

Workers who handle chemicals, hazardous materials, or potentially infectious substances may use gloves, safety glasses, respirators, protective clothing, and boots to reduce exposure. PPE provides protection only when it is properly used, removed, cleaned, stored, and disposed of.

Contamination can spread when workers:

• Leave a contaminated work area without washing their hands or face.
• Wear contaminated clothing or footwear into offices, break rooms, vehicles, or homes.
• Handle phones, tools, door handles, steering wheels, or personal belongings while contaminated.
• Improperly remove contaminated PPE.
• Eat, drink, smoke, chew gum, or apply cosmetics before washing.
• Take contaminated tools or equipment into clean areas.
• Wash contaminated work clothing with household laundry.

Contaminants of Concern

Depending on the work being performed, contaminants may include:

• Lead and other toxic metals.
• Asbestos and hazardous fibers.
• Solvents, paints, coatings, and other chemicals.
• Pesticides and herbicides.
• Concrete, silica-containing, or other hazardous dusts.
• Fiberglass and other irritating materials.
• Blood and other potentially infectious materials.
• Poison ivy, poison oak, and other irritating plant oils.

Some contaminants can be absorbed through the skin, inhaled, or accidentally ingested when contaminated hands contact the mouth, food, beverages, or cigarettes.

Prevent Cross-Contamination at Work

Maintain a clear separation between contaminated work areas and clean areas whenever hazardous substances are present.

Workers should:

• Wear the PPE required for the hazard and task.
• Remove contaminated PPE before entering designated clean areas.
• Follow proper procedures when removing gloves and protective clothing to avoid contacting contaminated surfaces.
• Wash hands and exposed skin thoroughly after handling hazardous materials and before eating, drinking, smoking, or leaving the work area.
• Never eat, drink, smoke, or store food in contaminated work areas.
• Clean or decontaminate reusable PPE according to established procedures.
• Dispose of single-use contaminated PPE in designated containers.
• Keep contaminated tools and equipment separate from clean equipment.
• Clean contaminated equipment before removing it from the work area when required.
• Keep break rooms, offices, vehicles, and other clean areas free of contaminated clothing and equipment.

Prevent Take-Home Exposure

Contaminants carried home from work can expose family members who were never present at the jobsite. Children may be particularly vulnerable because of frequent hand-to-mouth activity and contact with floors and other surfaces.

Where the work involves hazardous contamination:

• Change out of contaminated work clothing and footwear before leaving the worksite whenever required or feasible.
• Use designated changing and washing facilities when provided.
• Shower before leaving work when required by the applicable exposure-control procedure.
• Never bring contaminated PPE into the home.
• Store work clothing separately from clean clothing.
• Follow company procedures for laundering contaminated clothing.
• Do not take contaminated clothing home when regulations or company procedures require employer-provided laundering or disposal.
• Keep contaminated tools and equipment out of personal vehicles whenever possible.

Home laundering is not appropriate for every hazardous substance. Requirements for materials such as lead, asbestos, pesticides, or biological contamination may require specialized handling, decontamination, or employer-provided laundering.

Good Hygiene Is an Exposure Control

Personal hygiene is an important part of workplace exposure prevention. Wash thoroughly after working with hazardous substances and before touching food, beverages, personal items, or clean surfaces.

Remember: contamination you cannot see can still be hazardous. Keep hazardous substances in the designated work area by properly removing and decontaminating PPE, washing exposed skin, and preventing contaminated clothing, tools, and equipment from entering clean areas or going home.