How to Work Safely with - Toxic Materials

Toxic materials are substances that may cause serious harm to an individual if it enters the body. This document provides guidance on safe handling and storage practices, and how to work safely with toxic materials. For more information about the hazards of toxic materials and how they are identified, refer to the OSH Answers document called Toxic Materials and their Hazards.

Whenever possible, it is always best to avoid using a toxic material either by eliminating its use (by changing the method or process for example) or by substituting the toxic material with a less hazardous material. Unfortunately, it is not always possible to find a non-toxic substitute that still does the job effectively and safely.

When considering substitution, the first step is to obtain the Material Safety Data Sheets (MSDSs) for all possible substitute materials. Find out about all of the hazards (health, fire, chemical reactivity) of these materials before making any changes. Caution must be exercised so as to avoid introducing a potentially more hazardous situation. Choose the least hazardous materials that can do the job effectively and safely. Learn how to work safely with them, too.

For more information about this topic, please see the OSH Answers Substitution of Chemicals: Considerations for Selection.

To prevent exposure to a toxic material, control measures are used. Ventilation is a very common control measure for toxic materials. Well-designed and well-maintained ventilation systems remove toxic vapours, fumes, mists or airborne dusts from the workplace before workers are exposed. Removing the contaminated air reduces the hazard of toxic materials.

When considering exposure control measures such as ventilation, there are many considerations, including:

• Physical state of the toxic material (e.g. is it a paste? a powder?, a liquid?).
• Chemical properties (e.g. vapour pressure, boiling point, odour threshold, etc.).
• Toxicity (e.g. LD₅₀, LC₅₀).
• Other potential health effects (e.g. eye or skin irritation?, sensitizer?).
• Potential routes of exposure (inhalation? skin absorption?).
• Quantity used.
• Frequency of use (Once a day? Every day?).
• The job requirements (e.g. how the material is handled).
• Size and layout of the work area.

An assessment of the specific ways toxics are stored, handled, used, and disposed of is the best way to find out if existing ventilation controls (and other hazard control methods) are adequate.

Some workplaces may need a complete system of hoods and ducts to provide acceptable ventilation. Others may require a single, well-placed exhaust fan. In some situations, no special ventilation system may be needed when working with small amounts of toxic materials which do not give off airborne contaminants.

For the storage of toxic materials, ensure that the storage area is clearly identified with warning signs, is clear of obstructions, and is accessible only to trained and authorized personnel.

Before storing toxic materials, inspect all incoming containers to ensure that the containers are undamaged and are properly labelled. Do not accept delivery of defective containers. Also, be sure to store toxic materials in the type of containers recommended by the manufacturer or supplier.

Some other important points for storage of toxic materials include:

• Keep the amount of toxic material in storage as small as possible.
• Inspect storage areas and containers regularly for any deficiencies, including leaking or damaged containers, expired shelf-life or poor housekeeping. Correct all deficiencies as soon as possible.
• Ensure that containers are tightly closed when not in use and when empty. Keep empty containers in a separate storage area. Empty containers may contain hazardous toxic residue -- keep closed.
• Store containers at a convenient height for handling, below eye level if possible. High shelving increases the risk of dropping containers and the severity of damage, injury and/or exposure if a fall occurs.
• Store material within the temperature range recommended by the chemical manufacturer/supplier.
• To contain spills or leaks, the toxic material containers should be stored in trays made of compatible materials. For larger containers such as drums or barrels, provide dikes around the storage area and sills or ramps at door openings. Storage tanks are above ground and surrounded with a dike capable of holding entire contents.

Toxic materials must be stored properly. In general, the storage area for toxic materials should have the following characteristics. Many of these recommendations apply for safe chemical storage in general.

• Ensure that the storage area is well-ventilated and out of direct sunlight.
• Store toxics separately, away from processing and handling areas, eating areas and protective equipment storage. Separate storage reduces the amount of damage and/or injury caused in case of fires, spills or leaks. If totally separate storage is not possible, use physical separation to keep toxics away from incompatible materials.
• The storage area should be fire-resistant and constructed from non-combustible materials.
• Ensure that emergency eyewash/shower stations are readily available nearby and are tested regularly.
• Ensure that suitable fire extinguishers and spill clean-up equipment are available.

Safe handling and work procedures are crucial for workplaces where individuals use toxic materials. It is vital that people working with hazardous materials such as toxics are properly trained regarding the potential hazards. Remember, if, at any time an individual is unsure or has questions about working with a toxic material, they should always talk with the supervisor.

This section refers to general safe handling practices for toxic materials. Instructions and training for the specific handling of a particular toxic material used in a workplace is the responsibility of the supervisor (employer).

In general, when handling toxic materials:

• Use only the smallest amount necessary to do the job.
• Prevent the release of toxic vapours, dusts, mists or gases into the workplace air.
• Wear appropriate personal protective equipment (if necessary) to avoid exposure (eye, respiratory or skin) or contact with contaminated equipment/surfaces.
• Be aware of the typical symptoms of poisoning and first aid procedures. Report any signs of illness or overexposure immediately to the supervisor. Depending on the material, medical attention for an exposure may be required even if the exposure did not seem excessive. With some materials, symptoms of a severe exposure can be delayed.
• Do not return contaminated or unused material to the original container.
• Ensure containers are clearly labeled and inspect containers for leaks or damage before handling.
• Keep containers tightly closed when not in use.
• Ensure suitable emergency equipment for fires, spills and leaks are readily available.
• Ensure emergency eyewash/shower stations are readily available and are tested regularly.
• To prevent spillage, use proper tools to open containers and to transfer material.
• Pour toxic liquids carefully from the container to avoid splashing and spurting.
• Avoid any welding, cutting, soldering or other hot work on an empty container or piping until all toxic liquid and vapours have been cleared.
• Maintain good housekeeping (e.g. clean surfaces, no accumulation of dust).

Waste toxic material must be disposed of properly. Careless disposal of any hazardous waste presents a potential hazard to many individuals who may not be trained or equipped to deal with unexpected hazardous materials (e.g. caretaking staff, garbage collectors, plumbers, water treatment plant workers, firefighters, etc.). Careless disposal can also cause significant damage to the environment.

The following are some general recommendations for disposal of waste toxic materials:

• Always review federal, provincial and local (municipal) government requirements prior to disposal of toxic materials. In some cases, disposal by controlled incineration or secure landfill may be acceptable. Specific requirements may vary depending on the jurisdiction.
• Toxic chemical waste must NOT be flushed down sewer or sanitary drains as a method of disposal. This practice is illegal and unsafe.
• Do not mix hazardous waste materials with regular garbage destined for a landfill.
• Ensure that the waste container used is compatible with the waste material.
• Always ensure that the waste container is properly and accurately labelled.
• To avoid potential explosions, fires or spills, do not mix incompatible mixtures in a single waste container.
• Do not overfill liquid waste containers. Liquid waste containers should only be filled to about three-quarters capacity to allow for vapour expansion and to reduce the potential for spills occurring from moving overfilled containers.
• In general, store waste material in the same manner as the non-waste material. Always consult the MSDS for any specific storage and disposal recommendations from the manufacturer/supplier.
• Empty containers may contain toxic residues. Do not reuse the containers. Treat the container as hazardous waste unless the containers can be decontaminated safely and properly.

Good housekeeping is a very important way to prevent exposure to toxic materials. A clean and orderly workplace is safer for everyone.

• Have appropriate spill control equipment and procedures. Clean up any spills and build-ups of toxic materials promptly and safely using this equipment and procedures. Additional guidance may be available on the MSDS or from the supplier/manufacturer.
• Avoid dry sweeping of solid materials. Use a pre-wetting technique or vacuum equipped with high efficiency filter(s) instead.
• Properly dispose of unlabelled or contaminated chemicals.
• Ensure that all waste containers are compatible with the toxic material and that the containers are properly labeled and stored.

Personal cleanliness when working with toxic materials provides protection not only for you but protects others as well (such as co-workers and family members).

• Wash hands before eating, drinking, smoking or going to the toilet.
• Remove contaminated clothing and leather shoes or boots. Wash contaminated items immediately and thoroughly in water before re-wearing or discarding.
• Store food and tobacco products in "clean" (uncontaminated) areas.
• Avoid touching yourself (e.g. scratching your nose or rubbing your eyes) with contaminated hands.
• Do not chew gum when working with toxic materials.
• Wash thoroughly at the end of the workday even though you have done everything mentioned above.

Control measures such as ventilation, enclosure and work practices are examples of the preferred methods of protecting workers. If these measures are not feasible or unable to provide appropriate worker protection, then personal protective equipment may be required.

Choosing the right PPE for a particular job is essential. MSDSs should provide general guidance. Also obtain help from a qualified professional who knows how to evaluate the hazards of a specific job, especially those related to toxics, and how to select the proper PPE.

Before the toxic material is brought into the building and used:

• The appropriate PPE should be selected and be available.
• Workers should know where the PPE is and be trained to use it for emergencies as well as for normal operations.
• It is important to understand the limits of PPE, not just its capabilities.
• The Personal Protective Equipment Section of OSH Answers has several documents including the selection, use and maintenance of various kinds of PPE.

It is crucial that any required PPE be worn when specified for a job. PPE can be very effective but not if you don't wear it.

Avoiding Skin Contact with Toxic Materials

Some toxic materials can be harmful when in contact with your skin. In these instances, it may be necessary to wear protective equipment such as gloves, aprons, boots, hoods or other clothing, depending on the risk of skin contact. Choose clothing made of materials that resist permeation, penetration or damage by the chemical. The Chemical Protective Clothing document of OSH Answers has general information on selecting gloves and other chemical protective clothing. The MSDS should recommend appropriate materials that the protective clothing should be made of. If it does not, contact the chemical supplier for specific information.

Protecting the Eyes and Face from Toxic Materials

Eye protection is important when working with toxic materials. Selection of the most appropriate type depends on factors such as how the material is used, physical characteristics (e.g. fine powder, liquid, vapour, etc.) and potential health effects (e.g. eye irritant, skin irritant, toxicity through skin absorption, etc.). In some cases, it may be necessary to wear a face shield (with safety glasses or goggles) to protect the face from splashes. The Safety Glasses document in OSH Answers has information on selecting PPE for protecting the eyes and face. The current Canadian Standards Association (CSA) Standard Z94.3, "Industrial Eye and Face Protectors," provides additional advice on selection and use of eye and face protectors.

Avoid Breathing Toxic Dusts, Mists or Vapours

Proper selection and fitting of respiratory protection can be quite complex and any time it is used in a workplace, it must be carefully monitored and controlled to ensure worker safety.

If respiratory protection is required in the workplace, a respiratory protection program must be developed, written and maintained as described in the Respirator Selection document in OSH Answers. Further guidance for developing a program can be found in the current CSA Standard Z94.4, "Selection, Care, and Use of Respirators." Follow all legal requirements for respirator use and approvals. These may vary between jurisdictions in Canada.

Careful selection of the appropriate respirator style and cartridges is an important component of any respiratory protection program. Respiratory equipment must be properly sized and the user must know how to fit-test, clean, maintain and store the equipment. Users must also know how often to change the cartridges. NEVER assume that "smelling" the toxic material will indicate when to change the cartridge.

The time to figure out what to do during an emergency is BEFORE it happens. Be ready to handle emergencies such as fire, leaks or spills quickly and safely.

In the event of an emergency involving a toxic material:

• Report leaks, spills or ventilation failures immediately.
• Evacuate the affected area at once if you are not trained to handle the problem or if it is clearly beyond your control.
• Alert other people in the area to the emergency; call for emergency services.
• Report the problem to the people responsible for handling emergencies where you work.
• Obtain first aid if you have been exposed to the toxic material.
• The MSDS and container label for a particular toxic material should give specific first aid instructions in case of exposure by skin or eye contact, inhalation, or swallowing.
• In the event of skin or eye contact, the first aid response usually involves flooding the contaminated area with large amounts of water. The specific first aid recommendations can vary from one toxic material to another, however, depending on the nature (properties and hazards) of the material.
• Emergency eyewash stations and safety showers should be present wherever accidental exposure to toxics might occur. These are available from safety equipment retailers.
• Only specially trained people, equipped with the proper tools and protective equipment, should handle the emergency. Nobody else should go near the area until it is declared safe.
• Planning, training and practicing for emergencies are important so that everyone knows what they must do.

The MSDSs for the materials being used on the job are a good starting point for drawing up an emergency plan. MSDSs have specific sections on toxicity, fire and explosion hazards, including suitable fire extinguishing equipment and methods, spill clean-up procedures and first aid instructions. If the directions in each MSDS section are not clear or seem incomplete, contact the material's manufacturer or supplier for help. You can obtain help in developing emergency plans from many other sources too. Local fire departments can assist with fire emergency plans and training. Occupational health and safety and environmental enforcement agencies, provincial safety associations, St. John Ambulance, insurance carriers, professional societies in occupational health and safety, labour unions, trade associations, some local colleges and universities, and CCOHS can supply useful information at little or no cost.

Following these basic safe practices will help protect you from the hazards of toxic materials:

• Know which materials you work with are toxic materials. In addition, be aware of ALL of the hazards (e.g. fire/explosion, corrosivity, chemical reactivity) of the materials used in your work.
• Read the MSDSs for all of the materials that you work with. Know how to use these materials safely and be able to protect yourself and your co-workers.
• Follow the work practices specified by your employer. Your employer must provide specific training on how to work safely with these materials at your worksite.
• Ensure that engineering controls (e.g. ventilation) are operating. Closed handling systems may be necessary to prevent the release of the material (dust, mist, vapour, gas) into the workplace.
• Report ventilation failures, leaks or spills to your supervisor immediately.
• Store, handle and use toxic materials in well-ventilated areas away from combustible and other incompatible materials.
• Wear the appropriate personal protective equipment that your employer specifies for the job. This equipment may include respiratory protection, goggles, face shield, and chemical protective clothing, such as an apron and gloves made from materials that protect against the chemicals being handled.
• Be aware of the typical symptoms of an overexposure and appropriate first aid procedures. Report any signs of illness immediately to your supervisor.
• Keep containers closed when not in use.
• Keep only the smallest amounts possible (not more than one day's supply) in the work area.
• Do not return contaminated or unused toxics back to the original container.
• Practice good housekeeping, personal cleanliness and proper equipment maintenance.
• Handle and dispose of toxic wastes safely.
• Know how to handle emergencies (fires, spills, personal injury) involving the toxic materials you work with.
• Follow the health and safety rules that apply to your job.