Thanks for the question. Our supplier who compounds our vinyl resin has stated they have never heard of this happening. They also said if there was any leaching of any chemical it would most likely not be enough to show up on a test. Our products have been designed and used for Agriculture and Ornamental watering for over 30 years and we honestly have never heard of any leaching of any of the resins we use. Even organic farmers have been using our products for years. As for using silicon tubing, we have not tested this type of product in the field. We have concerns if using a clear tubing, algae will grow inside the tubing, eventually clogging the dripper and micro sprays. Also, we do not know how it will perform laying on the ground or underneath the soil. Hopefully this has answered your question and please feel free to call us. I really appreciate your concern on this and thank you for asking this question!