Shell Development Co., in cooperation with Mark Tool Co., began a program to produce the optimum anti-foulant for offshore structures. Two proven materials -- copper-nickle and SPLASHTRON^® -- were selected to work together as a unit. The result was BIO-SHIELD. Mark Tool Co. manufactures Bio-Shield by license under Shell's U.S. patent number 4,415,293.

BIO-SHIELD keeps marine growth from attaching to conductors and platform members in the first place, allowing designers to take full advantage of the cleaner profiles, and eliminating the necessity of any expensive removal operations.

Copper was chosen because of its long history as an effective anti-foulant, its ease of fabrication, and its comparatively low cost.

SPLASHTRON, manufactured by Mark Tool Co., was selected as the insulating layer for several reasons:

1. It bonds strongly to metal, both steel and copper-nickle
2. It has proven to ave a very long service life in the harsh "splash zone" environment.
3. It is a good electrical insulator
4. It provides a bonus in corrosion protection for the metal surface to which it is attached.