As a fully trained & certified vehicle air conditioning service technician and speaking to others within the trade we are becoming increasingly concerned by the sale of these kits to members of the public. The reasons for these concern fall into three areas. 1. Health & Safety issues to the user - R134a refrigerant coming into contact with skin or eyes can cause freeze burns. To comply with current legislation a/c technicians must have a Certificate of Refrigerant Handling. This ensures we are aware of the risks relating to its usage. 2. Damage to vehicle issues - Any a/c system that contains air/moisture must go through a vacuum process to remove the contaminant. Failure to carry this out will result in corrosion to the aluminium tubing which makes up 90% of the system. Many older vehicles that have had little or no a/c maintenance will contain moisture. A/c technicians have specialist equipment to check for contamination & to remove during the vacuum process. They will also refill the system to its correct level to maintain performance. 3. Environmental Issues - Many systems due to lack of maintenance will suffer with leaks. Injecting refrigerant into these systems will result in the contents leaking away into the atmosphere. As R134a is a greenhouse gas this has a direct impact on the environment. A professionally carried out recharge can in many cases be not much more expensive than a DIY Kit. Why take the risk, you know it makes sense. This guide is brought to you by Autoclimate Care, see our eBay shop Vehicle Air Conditioning Supplies.