Soil and Groundwater Remediation

REMOTOX® is one of the most effective and routinely used reagent for in-situ geochemical fixation of Hexavalent Chromium (VI).

Application Advantages:

Product Features:

  • A strong yet relatively inexpensive reducing agent.
  • Its residues are inert and non-toxic.
  • No need to dissolve prior to use as compared to solid material.
  • NSF/ANSI Standard 60 approved for drinking water treatment.
  • REMOTOX® is manufactured in an inspected and certified organic facility here in the United States.

The US EPA has identified Calcium Polysulfide as a reagent suitable for use in in-situ chemical reduction (ISCR), stabilization and solidification of multiple contaminants. Several abstracts and studies are available through CLU-IN Technologies, the Hazardous Waste Clean-Up Information website, sponsored by the US EPA. 

Bench scale evaluation, case studies and dosage guidelines on Calcium Polysulfide for the remediation of hexavalent chromium can also be found in the Chromium (VI) Handbook, available for purchase at or at

This product has proven to be effective under a wide range of site conditions. In the in-situ remediation of soil and groundwater, it is considered more stable and persistent than other reductants in subsurface environments, and it is relatively safe to handle in the field and easy to apply. 

Remotox Calcium Polysulfide for the stabilization of heavy metals.

Calcium Polysulfide for in situ chemical reduction of chlorinated organic compounds.

Calcium Polysulfide for removal of heavy metals from fly ash.

Calcium Polysulfide application guidelines for treatment of hexavalent chromium.

REMOTOX®, a 29% Calcium Polysulfide Solution, precipitates highly soluble metals as less soluble, less toxic metal sulfides. In the case of chromium, the metal precipitates as chromium hydroxide.

Calcium Polysulfide is fairly safe to handle out in the field. It is a non-toxic remedial amendment that oxidizes under aerobic conditions to form calcium, elemental sulfur and sulfate.  When introduced into the environment, Calcium Polysulfide breaks down to form bisulfide, aqueous hydrogen sulfide and other sulfur compounds.  Heavy metal ions are precipitated as less soluble, less toxic metal sulfides by these breakdown products. Metal hydroxides change solubility with changes in pH, whereas metal sulfides remain insoluble within a wide pH range. See Solubility of Metal Hydroxides and Sulfides as a Function of pHWhile effective treatment by Calcium Polysulfide can be achieved over a wide pH range, best results are typically obtained within pH 7-10. Adjustments to the pH of the treatment system can enhance the metal precipitation process. See pH Guidelines for Treatment of Soluble Metal Streams.

For additional information, studies and assessments, samples or pricing information, please don't hesitate to contact us.