Magnesium hydroxide – Mg (OH)2 – is a safe and effective choice of antacid for OAE projects.

To read more information about the safety built into our process, see our Safety pages.

Process Safety

Why Magnesium Hydroxide?

There are multiple types of alkalinity that may be used for ocean alkalinity enhancement. Our current projects use magnesium hydroxide.

Magnesium hydroxide is:

Well Understood. Magnesium hydroxide has been studied for decades. It has been used widely in wastewater treatment facilities for nearly a century, primarily for pH control and purification purposes. There are established networks of trustworthy magnesium hydroxide suppliers around the globe and reliable methods for testing its purity.

Safe for Organisms. Significant scientific research has been conducted into magnesium hydroxide’s safety, including its interactions with marine ecosystems and organisms. It is widely considered to be safe, non-toxic, and not to bioaccumulate.

Slow to Dissolve. When mixed with seawater, magnesium hydroxide dissolves slowly, releasing its alkaline molecules over days and weeks. This delayed release protects the seawater from experiencing a sudden change in pH that could harm marine life. Other types of antacid that can theoretically be used in ocean alkalinity enhancement are more soluble, and their effect on seawater pH is more immediate and potentially more dangerous.

For these reasons, our initial projects use magnesium hydroxide.

Ultimately, however, our portfolio approach emphasizes using the appropriate source of alkalinity for each site and each set of circumstances. We aim to use the right form of alkalinity, in the right place, at the right time. To that end, we continue to investigate additional hydroxides that may be safely used to better accommodate the individual circumstances of future sites.

Planetary’s Supply Chain

Currently, Planetary’s primary supplier of magnesium hydroxide is Garrison Minerals. Garrison specializes in producing high-quality magnesium mineral products and serves customers in the food, pharmaceutical, and environmental sectors. They have been supplying magnesium hydroxide to wastewater treatment plants directly for years.

Planetary selects batches of magnesium hydroxide from Garrison’s facility in Houston, Texas. Samples from these batches are sent in dry form to an independent lab to be tested for impurities.

There are many other suppliers of alkalinity worldwide. As Planetary expands, we plan to identify other trustworthy suppliers, particularly suppliers close to our project sites. This will help us improve the efficiency of our projects and reduce our carbon footprint without sacrificing our standards of safety and purity.

Our Verification Process

Before a batch of alkalinity is shipped to a site, Planetary tests it to ensure that the material aligns with regulations and safety specifications, and performs according to its matching Technical Data Sheet.

The testing, conducted by independent and accredited labs, includes impurities and trace metals analysis through mass spectrometry.

No batch that includes impurities above the predetermined safety thresholds set by regulators will be approved for use.

Once the sample is approved and verified as safe, Planetary begins processing the mineral, grinding large rocks into particles smaller than beach sand, which will dissolve in seawater more easily.

The powdered alkalinity can then be shipped to a project site.