MSM occurs naturally but is manufactured as a dietary supplement by different methods.
MSM occurs naturally in many common foods such as tomatoes and milk. However, its concentrations are so small that it is not feasible to commercially "extract it from nature." Commercial MSM of high purity is chemically identical to that found in nature.
All MSM is manufactured using a chemical synthesis process of reacting two raw materials, dimethyl sulfoxide and hydrogen peroxide. This reaction forms a new molecule: MSM or dimethyl sulfone. After reaction, a purification process is needed to remove any impurities from the MSM. Two commonly accepted purification processes used in most chemical and food processing plants are distillation and crystallization. Distillation is the favored process for producing high purity MSM, where heat is used to separate compounds by their unique boiling points. MSM has a boiling point of 478ºF. The distillation of MSM results in a very pure product. Conversely, purification by crystallization can be adversely affected by the use of impure solvents, potentially leaving undesirable or toxic by-products.
If MSM is not manufactured properly, or is produced in a facility that makes multiple products with improper sanitation procedures, contamination is likely. There may also be a chance that impurities (such as heavy metals or chlorinated hydrocarbons) from the water used in the synthesis and crystallization process will remain in the final product.
Other factors that determine the purity of synthesized MSM is consistent product formulation and strict process control procedures. A good MSM manufacturer uses in-process control and rigorous product testing to ensure the product is indeed pure.
The nutrition industry has established standards for testing MSM material so that all manufacturers use the same types of procedures and instruments for testing. These standards are developed by AOAC International, an independent, NIH-sponsored, FDA-endorsed international community of analytical chemists. Industry guidelines recommend that raw material and finished products manufacturers use these accepted methods to ensure consistent quality. These methods establish "a gold standard" by which all products can be uniformly measured.
Leading MSM manufacturers and pharmaceutical laboratories have developed highly sensitive laboratory tests using state-of-the-art testing equipment so that even minute impurities can be identified. These tests include: