Technical comparison of curing methods: extractables, purity, cost and regulatory implications for food and pharmaceutical applications.

Introduction

The choice of curing method for silicone tubing significantly impacts its purity, performance and regulatory compliance. This article provides a detailed technical comparison to help engineers and quality teams make informed decisions.

Platinum-Cured (Addition-Cured) Silicone

Platinum-cured silicone uses a platinum catalyst in an addition-cure reaction. This process produces no harmful by-products, resulting in tubing with exceptionally low extractables and the highest purity levels. Key advantages include:

• Lowest extractable levels (critical for pharma and biotech)
• No peroxide decomposition by-products
• Superior transparency and clarity
• Compliance with FDA, USP Class VI and ISO 10993
• No taste or odor transfer

Peroxide-Cured Silicone

Peroxide-cured silicone uses organic peroxides as catalysts. While less expensive, the curing process can leave peroxide decomposition by-products (such as 2,4-dichlorobenzoic acid) that may extract into the transferred fluid. This makes peroxide-cured tubing less suitable for critical pharmaceutical and biotech applications.

Comparison Summary

Property	Platinum-Cured	Peroxide-Cured
Extractables	Very Low	Higher
By-products	None	Peroxide residues
USP Class VI	Compliant	May not comply
Cost	Higher	Lower
Transparency	Excellent	Good

Recommendation

For food, pharmaceutical, biotech and medical applications, platinum-cured silicone tubing is strongly recommended due to its superior purity and regulatory compliance. Peroxide-cured tubing may be acceptable for less critical industrial applications where extractables are not a concern.

All Rekky silicone tubing is platinum-cured. Browse our product range or request a quote.