Common O-Ring materials that are SUITABLE for dynamic and static seal in the environment containing Concentrated Ammonium Hydroxide include

• Butyl: Butyl (IIR) is a synthetic rubber, a copolymer of isobutylene and isoprene.
• Chemraz: Chemraz combines the resilience and sealing force of an elastomer with chemical resistance approaching that of PTFE.
• Fluorosilicone: Fluorosilicone combines excellent low-temperature performance of silicone with improved chemical resistance.
• Hypalon: Hypalon is the traenme of a clasof Chlorosulfonated Polyethylene (CSM).
• Kalrez: Kalrez is the tradename for a perfluoroelastomeric material.
• Neoprene: Neoprene is a homopolymer of chlorobutadiene (CR).
• Silicone: Silicone is a semi-organic elastomer with outstanding resistance to extremes of temperature.
• Virgin Teflon: Because Teflon is a hard plastic rather than a stretchy elastomer, it is uncommon to see an o-ring that is made entirely of Teflon.

The O-Ring materials below are USUALLY SUITABLE for static seal in the environment containing Concentrated Ammonium Hydroxide.

• Epichlorohydrin: Epichlorohydrin (ECO) has properties similar to nitrile rubber but with better heat and oil resistance as well as better low temperature flexibility.

The following O-Ring materials are SOMETIMES OK for static seal but not for dynamic seal in the environment containing Concentrated Ammonium Hydroxide.

• Buna-N (Nitrile): Buna-N, also known as Nitrile rubber, is a synthetic rubber copolymer of acrylonitrile (ACN) and butadiene.
• Ethylene-Propylene: Ethylene-propylene (EP) is a copolymer of ethylene and propylene.

O-Ring materials that are NOT SUITABLE for using in the environment containing Concentrated Ammonium Hydroxide include

• Polyacrylate: Polyacrylate (ACM) is a class of copolymer of ethyl and acrylates.
• Polysulfide: Polysulfide was one of the first commercial synthetic elastomers.
• Millable Polyurethane: Millable Polyurethane rubber is made from both polyester and polyether polyols.
• Styrene Butadiene: Styrene-Butadiene rubber (SBR) has properties similar to those of natural rubber.
• Vamac: Vamac is the tradename of a class of Ethylene Acrylic elastomer (AEM).