What is FHA™?
FHA™ is a carbonaceous adsorbent used in water treatment — a black, granular or powdered solid that is insoluble in water, with a pH of 8.5 to 12 at 25 °C.
Fluid Tech supplies it as one of three isotope-specific media used together on liquid radioactive waste: FHA™ alongside the WTZ 100® and WTZ 200® natural zeolites. Where the zeolites are used for targeted removal of cesium and strontium, FHA™ has been deployed against transuranics, strontium and activated cobalt.
The approach behind all three is selective capture rather than bulk solidification — concentrating activity onto a small volume of loaded media so the treated stream can be discharged and the media itself managed as the waste form.
What is FHA™ made of?
The Safety Data Sheet lists two components by weight:
| Component | CAS number | % by weight |
|---|---|---|
| Hydroxyapatite | 1306-06-5 | 88 – 93%* |
| Carbon | 7440-44-0 | 7 – 12%* |
*The SDS designates that a specific chemical identity and/or percentage of composition has been withheld as a trade secret.
Technical specifications
Physical and chemical properties as published in the Safety Data Sheet:
| Physical state | Granular or powdered solid |
|---|---|
| Color | Black |
| Odor | Non-specific |
| pH | 8.5 – 12 @ 25 °C |
| Bulk density | 560 – 720 kg/m³ |
| Solubility (water) | Insoluble |
| Explosive properties | Class B – non-explosive |
| Stability | Stable at ambient temperatures |
Melting point, boiling range, flash point and evaporation rate are listed as not applicable; flammability and auto-ignition temperature are listed as not determined.
Where has FHA™ been used?
Two deployments are documented in the technical record, both on nuclear liquid waste.
Salem Nuclear Station — activated cobalt, 2023
EnergySolutions ran a small-scale ion-exchange column test in the plant's count room, comparing FHA™ against WTZ 100®. Running ALPS effluent through 200 ml of FHA™ at 20 ml/min — a ten-minute contact time — brought cobalt below the plant's administrative limit for environmental discharge. FHA™ was also tested on higher-conductivity influent and still removed cobalt below the limit, indicating that higher conductivity does not interfere with cobalt removal. The report records that FHA™ met the discharge limit where the plant's installed process could not.
Hanford 105-K West Fuel Storage Basin
During dewatering and decommissioning of the basin, FHA™ targeted transuranics and strontium while WTZ 100® and WTZ 200® targeted cesium and strontium. The selectivity concentrated the activity so that each loaded module could ship to the Environmental Restoration Disposal Facility as Low-Level Waste.
Publication, testing, or permitting by a government laboratory, contractor, or agency does not constitute endorsement of any commercial product.
How does FHA™ differ from WTZ 100® and WTZ 200®?
They are complementary rather than alternatives — the three have been deployed together on the same project.
- WTZ 100® and WTZ 200® — natural zeolites, used for targeted removal of cesium and strontium
- FHA™ — hydroxyapatite adsorbent, deployed against transuranics and strontium at Hanford and activated cobalt at Salem
Which media suit a given stream depends on the isotopes present, the chemistry of the effluent, and the discharge target. Column testing on actual influent is the usual way to settle it — that is what was done at Salem.
Is FHA™ hazardous to handle?
The Safety Data Sheet assigns no signal word and identifies no other hazards, treating the material as a nuisance dust at 10 mg/m³ TWA over 8 hours. It is not classified as a dangerous material and is not DOT regulated.
The SDS nonetheless specifies handling precautions:
- Tight-fitting safety goggles, suitable gloves, lightweight protective clothing and a dust mask
- Minimize dust formation; keep dry
- Keep away from strong oxidizing agents and strong acids
- May contain trace quantities of ammonia that can be released during initial washing — ensure adequate ventilation
- Thermal decomposition releases carbon dioxide; a little hydrogen sulfide may be given off on reaction with mineral acids
How is it supplied?
FHA™ is available by quote — distributor inquiries welcome. Tell us the isotopes of concern, the effluent chemistry and your discharge target, and our team will help scope the media and the configuration.
Frequently asked questions
What is FHA™ made of?
The Safety Data Sheet lists FHA™ as hydroxyapatite (CAS 1306-06-5) at 88–93% by weight and carbon (CAS 7440-44-0) at 7–12% by weight. Both figures are noted on the SDS as withheld in part as a trade secret. It is supplied as a granular or powdered black solid, insoluble in water, with a pH of 8.5 to 12 at 25 °C.
What has FHA™ been used for?
Two documented deployments. In a 2023 column test at Salem Nuclear Station run by EnergySolutions, FHA™ brought activated cobalt below the plant's administrative limit for environmental discharge, and continued to do so on higher-conductivity influent. At the Hanford 105-K West Fuel Storage Basin, FHA™ targeted transuranics and strontium alongside WTZ 100® and WTZ 200®, with the selectivity concentrating activity so each loaded module could ship as Low-Level Waste.
How does FHA™ differ from WTZ 100® and WTZ 200®?
They are complementary isotope-specific media rather than alternatives. WTZ 100® and WTZ 200® are natural zeolites used for targeted removal of cesium and strontium. FHA™ is a hydroxyapatite adsorbent, used at Hanford for transuranics and strontium and at Salem for activated cobalt. The three have been deployed together on the same project.
Is FHA™ hazardous to handle?
The Safety Data Sheet assigns no signal word and identifies no other hazards, treating the material as a nuisance dust with a 10 mg/m³ TWA over 8 hours. It is not classified as a dangerous material and is not DOT regulated. The SDS still directs users to wear tight-fitting safety goggles, suitable gloves, lightweight protective clothing and a dust mask, to minimize dust formation, and to keep the product dry and away from strong oxidizing agents and strong acids. It notes the material may contain trace quantities of ammonia that can be released during initial washing, so adequate ventilation should be ensured.
In the technical record
Documents in the Technical Library that reference FHA™:
- Removing Activated Cobalt at Salem Nuclear Station with FHA & WTZ 100
- Hanford 105-K West Fuel Basin Cleanup and Decommissioning
- Development and Testing of Two Vitrification-Compatible Classes of Ion-Specific Media
- Novel Modular Isotope-Specific Removal Systems — Magnox Pond Trials
Publication, testing, or permitting by a government laboratory, contractor, or agency does not constitute endorsement of any commercial product.
Treating a liquid radwaste stream?
Tell us the isotopes and the discharge target, and our team will help scope the right media.
Content reviewed August 2026 · FHA™ Safety Data Sheet FTL-080-0021, Revision 01 (December 8, 2022) · Fluid Tech Technical Library entries for Salem Nuclear Station (2023) and Hanford 105-K West.