Reaxis®  C129 – Stannous Octoate - Stannous Octoate

REAXIS® C129 (Stannous Octoate) is an inorganic tin carboxylate that consists of one of the highest metal contents for a liquid-based inorganic tin carboxylate, often used for polylactide polymerization. Chemically, REAXIS® C129 is commonly referred to as either stannous octoate or 2-ethylhexanaote. REAXIS® C129 is an ideal candidate when looking for alternatives for organotins, such as REAXIS® C218 (Dibutyl Tin Dilaurate) and REAXIS® C248 (Dibutyl Tin Oxide), used as a homogenous catalyst in polyurethane, silicone, and esterification applications. Given its inorganic tin nature, REAXIS® C129 can be used in high temperature applications. REAXIS® C129 is typically supplied in a neat form with very low levels of excess acid. C129 is stable with various diluents including, plasticizers, polyols, esters, and mineral oils.  Similar inorganic tin products with high metal content would be REAXIS® C125 (Stannous Neodecanoate), REAXIS® C160 (Stannous Oxalate) and REAXIS® C154 (Stannous Chloride).

For more information, read our technical bulletins on Bio-Based Catalysts and the Chemistry and Toxicity of Inorganic Tins.

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Technical Information

  • Product Category Inorganic Tin

  • Chemical Name Stannous Octoate

  • CAS Number 301-10-0

Typical Specifications

Parameter Range
Stannous Tin (%) 27.2 - 29.3
Tin (II) /Total Tin Content (%) 97.0 Min
Color (Gardner Number) 3 Max
Density (g/ml) 1.23 - 1.27
Viscosity (cP @ 20°C) 400 Max

International Regulatory Listings

  • TSCA (US) Yes

  • DSL (Canada) Yes

  • REACH (EU) Yes

  • AICS (Australia) Yes

  • KECI (South Korea) Yes

  • IECSC (China) Yes

  • ENCS (Japan) Yes

  • TCSI (Taiwan) Yes

  • NZloC (New Zealand) Yes

  • PICCS (The Philippines) Yes


REAXIS® C129 is typically used in various catalysts and lubricant applications. REAXIS® C129 is used as a homogeneous tin catalyst in polyurethane, silicone (condensation reaction) and esterification chemistries in a wide range of applications including coatings, adhesives and sealants, elastomers, and foams.  For lubricant applications, REAXIS® C129 is used given its liquid nature, high metal, and low residual acid content. REAXIS® C129 can be used as an alternative to zinc-based products such as REAXIS® C620 (Zinc Octoate).


Due to its high metal content, REAXIS® C129, is a good candidate for the above-mentioned chemistries and applications. In regard to polyurethanes, REAXIS® C129 is the work-horse catalyst in TDI-based flexible forms. Similar to organotins, inorganic tins are more selective to NCO/OH reactions and are thus good gelation & polymerization catalysts. For catalyzing silicone condensations, has shown, for example, to provide faster reactivity, compared to REAXIS® C218 in select acetoxy- and alkoxy-based formulations. REAXIS® C129 has proven to be a viable replacement for organotins such as REAXIS® C248, in the synthesis of a wide range of esters. In regard to stability, inorganic tins such as REAXIS® C129, do show a greater sensitivity to oxidation degradation compared to organotins. This latter effect is due to the presence of the Sn (II) species present in all inorganic tin products.

Package & Storage

  • 485 lb (220 kg) steel drum
  • 2756 lb IBC

REAXIS® C129 should be stored in the original packaging. The container should be closed tightly after each use to maximize shelf life. Characteristic of most inorganic tins (Sn(II)), the primary cause of instability would be oxidation.

Safety and Handling

Before use of Reaxis products please refer to the relevant Safety Data Sheet (SDS) for safety and toxicological data as well as for the information on proper transportation, storage, and use. SDSs are available by request via our web site, contacting your local representative, or emailing direct to

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This information is provided to the best of our knowledge but without obligation. Reaxis is not liable for any incorrect or missing information. This data sheet becomes invalid upon publication of a new version. Please contact us for the latest version.

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