1. Parylene A Safe, Environmentally Friendly Coating June 18, 2008
Lamar Young
7645 Woodland Drive
Indianapolis, IN 46278

2. Parylene C: Vapor Deposition PolymerizationH 2 C l H 2 C n l
Chemical formula: C8H7Cl
(repeat unit)
Molecular weight:
Elemental analysis:: C, 69.33%; H, 5.09%; Cl, 25.58%

3. Parylene – A Safe, Environmentally Friendly Coating
Problem
Recent proposed restrictions on Halogenated compounds have created concerns for Parylene. Parylenes are getting included with ‘hazardous’ substances.
The Parylene family includes 4 unique types of Parylene, 3 of which include Halogens.
These 3 make up the vast majority of Parylene films supplied in the world-wide market.
Restrictions on these products would impact all industries; military, aerospace, medical, automotive, semi-conductor, and consumer electronics.

4. Parylene – A Safe, Environmentally Friendly Coating
Problem
The presence of Halogens do not indicate that it is hazardous or harmful.
The excellent performance of these Parylene types is due to the presence of Halogens in its chemical structure.
Halogens may be present in various forms and may not create any environmental or health issues.
For example, Parylene C (containing Chlorine) has been used in many implantable devices and electronics for the past 30 years without any known adverse effects.

5. Parylene – A Safe, Environmentally Friendly Coating
Parylene C has not shown any toxicity, and is not considered a toxic substance or pollutant.
Pyrolysis of Parylene C, simulating incomplete incineration, did not create any dioxins.
Pyrolysis gives toluene, xylene, chloroform methylene chloride, hydrogen chloride and high molecular weight hydrocarbons.
Parylene C is currently used in implantable devices and has been in service for the past 30 years without any issues.
It is not possible to suggest a replacement to medical industry without any technical evidence that there is an issue, and without a qualified alternative. So far, there is no alternative available.
Parylene C is a biocompatible coating and we maintain both drug and device master files with FDA. It has successfully passed biological evaluations (per FDA/ISO standards).
USP tested and certified as a Class VI Plastic (acute systemic toxicity, irritation/intracutaneous reactivity, and implantation).

6. Parylene – A Safe, Environmentally Friendly Coating
It is almost impossible to replace other existing applications of Parylene C (widely used) in the market. This is primarily due to its specific properties and existing qualification requirements by the customers. Examples: Military, Electronics, Automotive market.
There is no other chlorine free coatings available in the market that can replace the exact properties of Parylene C.
A new material would have to be developed with no guarantee of the similar properties. Research may continue, but no one can assure that an alternative can ever be found.
Over the past thirty years, we have developed more than twenty molecules, but none of them could replace or provide similar properties and processing conditions of Parylene C.
The process emits no environmentally hazardous substances.

7. Parylene – A Safe, Environmentally Friendly Coating
Solution
Do not restrict all materials based on the presence of elemental Halogens.
Identify the individual compounds known of being harmful and list these.

8. Conclusion Recommendation
We strongly request that the RoHS revision not identify all Halogenated organic compounds as Hazardous Substances.