Chapter 13 Selection and Safe usage of cleaning solvents

Transcription

1 Selection and Safe usage of cleaning solvents NO MORE ODS

2 Application of R-141b Class II ozone-depleting substance (ODS)

3 Characteristics of R-141b Non-flammable High solvency power Easy to store and handle Evaporates relatively fast Wide range of application Destroys the ozone layer Occupational health hazard High GWP (713)

4 R-141b in RAC Material to be cleaned Copper tubing Aluminium tubing Steel tubing Nature of contaminants Carbon /Dirt Moisture/Oil Sludge Reasons for cleaning To prevent chocking of the system Better efficiency Increased compressor life

5 Reasons for sludge formation Flushing and leak testing using air Use of petrol for cleaning Improper evacuation Self-evacuation using system compressor Use of old compressor instead of vacuum pump Use of contaminated / used refrigerants Serious burns out of the stator

6 Nature and Effects of Contamination Chapter 13 Oil + Moisture + Dirt = Sludge Consequences Reduction in capillary diameter Reduced system performance due to Capillary chocking Increase in condensing temperature and pressure Reduced compressor life due to higher head pressure Copper tubing Sludge

7 Potential Alternative Solvents for removing sludge There are so many other chemical with different brand names Residues of flushing solvent can contaminate and damage an air conditioning system!! So flush properly. Try to adopt Good Servicing Practices & avoid chemical cleaning.

8 Recognizing Chemical Hazard Chapter 13 Hazard identification and recognition What effects? Who is affected? How affected? Contact with toxic solvent/ chemicals can cause acute/chronic health effect No solvent is completely safe for human beings Minimize the use of solvents

9 Exposure routes Chapter 13 The chemical may enter through following routes 1. Lungs = Inhalation of gases, vapours (Respiratory 60 %) 2. Skin = Absorption of gases, liquids and solids by direct contact with the skin (Absorption 30 %) 3. Mouth = Ingestion of chemicals due to poor personal hygiene (Intestines 10 %) It is essential to have good understanding about the risks involved in handling chemicals.

10 Current Practices Chapter 13 Excessive use of solvents Improper cleaning method Absence of preventive steps to avoid contamination Direct exposure/ contact with solvent Casual approach towards health hazards Improper personal hygiene Lack of awareness of safety issues Poor training of users

11 Follow Good Practices Minimum usage of solvent Selection of appropriate cleaning method Good ventilation in working area Use of Personal Protective Equipment Good house keeping Essentially wash hands with soap after use of solvents

12 How to minimize the use of solvent Chapter 13 Use solvents only if it is necessary Avoid excessive use of solvent by adopting the following methodology or any approach similar to it If the usage is high then use pump mechanism

13 Hazard control - Ventilation Regarded as one of the best forms of control apart from substitution and enclosure. Ensure good ventilation. Decide working position based on air flow

14 Recommended - Ventilation Good practice Air flow direction should be away from the user s nostrils. Wrong practice

15 Protection (Personal Protective Equipment) Goggles Masks Face shields, where frequent use of solvent Gloves