Leaching to Reduce Toxicity Level

Manufacturer: We are making medical products using NR latex compounds, which require a very stringent control of toxicity level of our products. We are attempting  improve our leaching process. Please give us some guidance.

John Woon (Senior Latex Consultant): I had answer many questions on leaching before. Please refer to my previous answer as follows:

Leaching is a big subject which entails at least 7 steps of mechanism. I can prepare a detailed report for you if required. In the mean time, here is my brief suggestion:

1) Higher leach water temperature is to be used to ensure maximum solubility of all the hydrophilic materials. But cold water leaching is to be included if non-ionic surfactants are also used.

2) Frequent replenishment with clean water is advisable.

3) Turbulence in the leaching tank would help.

4) Leach for as long a period as practically possible.

5) Adopt both wet and dry leaching.

6) Check copper (ion) level in the leach water.

If you are using a post-vulcanisable latex compound, I suggest you evaluate prevulcanised latex which has a comparatively low level of toxicity.