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TT-011-0808. Safety precautions and expert knowledge. Contents. Safety precautions for refrigerants. Safety precautions for pressurised gas tanks. Safety precautions for extraction and charging systems. Verification of refrigerants. Disposal of refrigerants/refrigeration oil.
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TT-011-0808 Safety precautions and expert knowledge
Contents • Safety precautions for refrigerants • Safety precautions for pressurised gas tanks • Safety precautions for extraction and charging systems • Verification of refrigerants • Disposal of refrigerants/refrigeration oil • Kyoto protocol • Climate change and global warming
Safety precautions for refrigerants • Product properties The different refrigerants used in motor vehicle air conditioning systems belong to the CFC material category (fully halogenated CFC, R12) or the new refrigerant generation based on chlorine-free, partly fluorated hydrocarbons (HFC, R134a). With regards to its physical properties, this is liquified refrigerant under pressure and may only be charged in pressurised gas tanks authorised and labelled for this purpose. For safe and correct use, certain regulations apply and these must be adhered to. This should be documented in a relevant operating instruction for refrigerants or refrigeration oil in a clean and legible manner. The contact person for this is your company health and safety representative.
Safety precautions for refrigerants • Handling refrigerants Caution! There is a risk from frosting! Do not open tanks containing refrigerant unless using the correct procedure! • If refrigerant tanks are opened, the contents could escape in liquid or vapour form. • This can occur in different intensities depending on the pressure in the tank. • The level of pressure depends on two conditions: • The type of refrigerant in the tank.The lower the boiling point, the higher the pressure. • How high the temperature is.The higher the temperature, the higher the pressure.
Safety precautions for refrigerants Caution! Use protective eyewear! • Handling refrigerants Wear protective glasses. They stop refrigerant and refrigeration oil coming into contact with the eyes and prevent serious damage from freezing, for example. Keep eye-rinse bottle or eye bath ready. Ideally, the local GP should be notified in advance about the use of such operating fluids. Read the relevant material data sheets.
Safety precautions for refrigerants Caution! Wear protective gloves and apron. • Handling refrigerants Refrigerants are very good at breaking down grease and oils. They can therefore remove the protective oily film upon contact with the skin. The skin becomes sensitive towards cold and germs. Skin contact with refrigerant leads to serious freezing as temperatures of up to –30 °C can occur through expansion.
Safety precautions for refrigerants Caution! Absolutely no smoking • Handling refrigerants Caution! Do not inhale refrigerant vapours in high concentrations. Escaping refrigerant vapours mix with the surrounding air and thereby reduce the oxygen required for breathing. If high concentrations escape, the workplaces must be well aired. Refrigerants can be broken down in the hot ash of a cigarette. The substances released as a result are toxic and must not be breathed in.
Safety precautions for refrigerants • Handling refrigerants Caution! Welding and brazing on air conditioning systems. Before welding and brazing on vehicles (near components of the air conditioning system), the refrigerant should be extracted and any residue should be purged using compressed air and nitrogen. The products released from refrigerant when subjected to heat are not only toxic, they are also extremely corrosive, thereby causing potential harm to pipe assemblies and system components. The products in question are essentially hydrogen fluoride. If a pungent smell is noticed, the products mentioned have already been released.Take all sensible measures necessary to avoid breathing in these substances as otherwise the respiratory tract, the lungs and other organs could become damaged.
Safety precautions for refrigerants • First aid in connection with refrigerants • On contact with the eyes or mucous membranes, rinse out with copious amounts of running water and seek specialist medical advice. • On contact with the skin, remove saturated clothing immediately and rinse affected areas of skin with copious amounts of water. • If refrigerant vapours are inhaled in high concentration, take the patient out into the open straightaway. Call a doctor. If breathing is impaired, use an oxygen mask. If the affected person is breathing only with great difficulty or not at all, move head back and artificially resuscitate.
Safety precautions for pressurised gas tanks • Handling pressurised gas tanks Caution! Prevent tank from falling over. Upright bottles should be prevented from falling over. Bottles placed flat on the floor should be prevented from rolling. Caution! Do not place tanks in the vicinity of heaters/radiators or other sources of heat. High temperatures can occur near heater panels/radiators. High temperatures mean high pressures, thereby increasing the risk of the maximum pressure in the tank from being exceeded.
Safety precautions for pressurised gas tanks • Handling pressurised gas tanks Caution! Do not throw tanks. On impact, the tank could be deformed in shape so much that it could split. Refrigerant would vaporise very suddenly, thereby releasing very high pressures. Bottle parts jettisoned through the air can cause serious injury. Incorrect transportation can cause the tank valve to break off. To protect the tank valves, the bottles should only be transported with the protective cap screwed on.
Safety precautions for pressurised gas tanks • Handling pressurised gas tanks Caution! Do not heat up tanks unless this is in a proper controlled environment. Under no circumstances should heat be applied with a naked flame. Excessive local heat application can cause the tank joints to alter their shape, thus reducing maximum pressure load on the tank. Furthermore, there is a risk of refrigerant being broken down through local application of heat.
Safety precautions for pressurised gas tanks • Handling pressurised gas tanks Caution! Seal empty tanks. Empty refrigerant tanks must be sealedwithout fail to prevent the ingress of damp. Damp can cause steel tanks to rust. This would weaken the tank wall. Furthermore, rust particles from the tank can cause faults if they enter the refrigerant circuit.
Safety precautions for extraction and charging systems • Working with the service station Caution! • Before connecting filling system to air conditioning unit, ensure that hand shutoff valves are closed. • Before decoupling the filling system from the air conditioning unit, ensure that the process is complete to prevent any refrigerant escaping into the atmosphere. • Once cleaned refrigerant from the filling system has been filled in a pressurised gas tank, the hand shutoff valves on the bottle and on the filling system should be closed. • Do not subject the filling system to any form of damp and do not use in wet environments.
Safety precautions for extraction and charging systems • Working with the service station Caution!
Safety precautions for extraction and charging systems • Working with the service station Caution!
Safety precautions for extraction and charging systems • Personnel, operation and induction training Excerpt from TRG 402 • 2.1 Filling systems may only be operated and serviced by personnel who • 1. have reached the age of 18, • 2. have the necessary specialist knowledge, • 3. expect to perform their tasks in a reliable manner. • 2.2 Work may also be carried out under supervision by personnel not covered by the conditions as per number 2.1, items 1 and 2.
Safety precautions for extraction and charging systems • Personnel, operation and induction training Excerpt from TRG 402 2.3 The employees must be given induction training before starting work for the first time and at sensible intervals thereafter, at least biannually, with regards to ... the particular hazards when working with pressurised gases ... the safety regulations, in particular TRG 402 ... the measures to adopt in the event of malfunction, damage and accidents ... handling fire extinguishing equipment and personal protective equipment ... operation and maintenance of filling/charging systems in terms of the respective manufacturer's operating instructions.
Verification of refrigerants • Operating log National environmental legislation requires that a log is kept on the consumption of refrigerants.
Disposal of refrigerants/refrigeration oil • Disposal regulations
Kyoto protocol • Overview The Kyoto protocol (which gets its name from the place where the conference was held, Kyōto, in Japan) was agreed on 11th December 1997 and is an arrangement of the United Nations framework convention on climate change (UNFCCC) with the aim of protecting the climate. The agreement, which came into force on 16th February 2005 and expires in 2012, prescribes, for the first time under national law, binding target values for the emission of greenhouse gases, which are the main cause of global warming. Kyoto
Kyoto protocol • Overview (continued) The increase in these greenhouse gases is mainly attributable to human activities, particular from the combustion of fossil fuels, cattle breeding and forest clearing. The gases regulated in the protocol are: carbon dioxide (CO2, serves as a reference valve), methane (CH4), nitrous oxide (laughing gas, N2O), partly halogenated fluorocarbons (HFCs), perfluorated hydrocarbons (PFCs) and sulphur hexafluoride (SF6). The protocol aims to reduce the annual greenhouse gas emissions from industrially-developed countries during the so-called first covenant period (2008–2012) by an average of 5.2 % compared with 1990.
Climate change and global warming • GWP value (Global Warming Potential) This value defines the risk that a respective substance has on global warming. CO2 is used as the benchmark here and is defined by the value 1. Stratosphere Refrigerant in comparison: R12 (CFC) = GWP value 14,400 R134a (CFC) = GWP value 1,300 R744 (CO2) = GWP value 1 This means: 1 kg of R134a contributes 1300 times more to the greenhouse effect than 1 kg of R744 (CO2). Troposphere Greenhouse effect