Many refrigerants evaporate rapidly at low temperatures. Direct skin or eye contact with liquid refrigerant or rapidly expanding vapour can cause frostbite or cold burns. Technicians must wear safety glasses or goggles, appropriate gloves, and avoid opening systems without proper tools and procedures.

Most fluorocarbon refrigerants are heavier than air and can displace oxygen in confined spaces. Accumulation of refrigerant can cause dizziness, loss of consciousness, or death. Adequate ventilation, continuous monitoring in mechanical rooms, and adherence to occupancy and machinery room codes are essential.

Some refrigerants and gases, such as ammonia or high-concentration CO₂, can be toxic or immediately dangerous to life and health. Exposure may occur through leaks, venting, or accidental mixing. Technicians must know the safety data sheet (SDS) information for each substance and follow established exposure limits and emergency procedures.

Hydrocarbon refrigerants, some HFO blends, and acetylene are flammable or combustible. Improper handling can result in fire or explosion. Ignition sources, including open flames, hot surfaces, and electrical sparks, must be controlled, and equipment rated for the correct hazardous location classification must be used where required.

Compressed gases and high-pressure refrigerants (such as R-410A or R-744/CO₂) present explosion and projectile hazards if cylinders, hoses, or components are mishandled. Only approved cylinders, regulators, gauges, and hoses rated for the working pressure are to be used.

When refrigerants contact open flames, welding arcs, or extremely hot surfaces, they can decompose into toxic, corrosive gases. Smoking, brazing, or open flames must not occur in areas contaminated with refrigerant leaks, and systems must be properly evacuated and purged prior to hot work.

Refrigeration oils can be irritating to skin and eyes and may contain dissolved refrigerant under pressure. Containers must be kept sealed to prevent moisture absorption, and used oil must be collected and disposed of according to environmental regulations.

Federal and provincial regulations control the use, handling, recovery, recycling, and disposal of ozone-depleting substances (ODS) and certain alternatives. These regulations typically:

• Prohibit venting of regulated refrigerants to the atmosphere.
• Require certified technicians to perform work on systems containing regulated refrigerants.
• Prescribe requirements for storage, transport, and labeling of refrigerant cylinders.

National and provincial building codes, mechanical codes, and fire codes set out requirements for refrigerating machinery rooms, emergency ventilation, detection and alarm systems, egress, and equipment location. These codes often reference safety standards such as CSA and ASHRAE.

Transport of Dangerous Goods (TDG) regulations, along with workplace safety rules, govern how cylinders of refrigerant and gas are filled, labeled, secured, and transported.

• Cylinders must be protected from heat and physical damage.
• Cylinders must not be stored in confined or occupied spaces.

Flammability classes describe the refrigerant's tendency to ignite and sustain combustion.

Toxicity classes indicate the potential for refrigerants to cause acute or chronic health effects when inhaled.

Contamination is both an operational and environmental concern. When a system becomes contaminated with air, moisture, acids, sludge, or mixed refrigerants:

• Heat transfer efficiency decreases, leading to higher energy use and operating cost.
• Corrosion and chemical reactions can form acids that damage copper, steel, and insulation.
• Compressors may overheat or fail due to poor lubrication and restricted refrigerant flow.
• Contaminated refrigerant and oil often cannot be reused and must be disposed of or reclaimed, increasing environmental burden.

Many synthetic refrigerants are potent greenhouse gases. If released to the atmosphere, they contribute directly to global warming. Refrigerants with very high GWP (such as some older HFC blends) are being phased down in favour of lower GWP HFOs, natural refrigerants, and optimized system designs.

Technicians must:

• Recover and recycle or reclaim refrigerants rather than venting to atmosphere.
• Locate and repair leaks promptly.
• Follow best practices for charging, testing, and maintenance to minimize losses.

Chlorinated refrigerants such as CFCs and many HCFCs have non-zero ODP and can damage the stratospheric ozone layer. This ozone layer protects life on earth from harmful ultraviolet (UV) radiation. International agreements and Canadian regulations have largely phased out CFCs and are phasing out HCFCs. Modern systems increasingly use zero-ODP refrigerants, but legacy equipment may still contain older substances which must be handled and disposed of carefully.

Beyond direct emissions, refrigeration systems affect the environment through:

• Energy consumption and the associated emissions from power generation.
• Improper disposal of oil, filters, and components contaminated with refrigerant or acids.
• Leaks of secondary refrigerants such as brines and glycols into soil or water.

Technicians help reduce overall environmental impact by maintaining system efficiency, using proper recovery and recycling procedures, and ensuring that waste streams are handled through approved recycling and disposal channels.