THPS vs Glutaraldehyde and Other Water-Treatment Biocides
THPS (CAS 55566-30-8) is one of several biocides used in industrial water systems. This page compares it with the products it is most often considered alongside, so you can choose or combine correctly.
The main water-treatment biocides
| Biocide | CAS | Type | Key traits |
|---|---|---|---|
| THPS | 55566-30-8 | Organophosphorus (non-oxidising) | Broad-spectrum; water-soluble; acidic; stable |
| Glutaraldehyde | 111-30-8 | Aldehyde (non-oxidising) | Fast-acting; broad-spectrum |
| DDAC / quaternary ammonium | 7173-51-5 | Quaternary ammonium (non-oxidising) | Surface-active; surfactant-like action |
| DBNPA | 10222-01-2 | Halogenated (non-oxidising) | Fast-acting; degrades quickly |
| Chlorine / Chloramine T | 127-65-1 | Oxidising | Strong oxidiser; cheap; corrosive to some systems |
Head-to-head
| Property | THPS | Glutaraldehyde | Quat (DDAC) |
|---|---|---|---|
| Mode | Non-oxidising | Non-oxidising | Non-oxidising |
| Speed | Effective, stable | Fast | Moderate; surface-active |
| Water solubility | Fully miscible | Miscible | Surface-active, cationic |
| Oilfield SRB control | Widely used | Widely used | Used |
| Corrosivity to equipment | Non-oxidising | Non-oxidising | Non-oxidising |
| Note | Acidic | Aldehyde handling | Cationic; compatibility with anions |
How to choose
- Need a stable, non-oxidising biocide for injection water? THPS (or THPS/glutaraldehyde blends).
- Need fast kill? Glutaraldehyde or DBNPA.
- Need surface-active control of biofilm? A quaternary ammonium biocide.
- Need cheap general disinfection where oxidation is acceptable? An oxidising biocide.
- Want the best coverage? Use a programme: rotate/alternate biocides with different modes of action.
Why programmes beat single products
Micro-organisms can become tolerant to a single biocide used continuously. Industrial practice is therefore to alternate or blend biocides: THPS with glutaraldehyde, or a non-oxidising biocide with an oxidising one, with dosing set by microbial monitoring. THPS fits these programmes well because it is water-soluble, broad-spectrum, non-oxidising and easy to dose.
Frequently Asked Questions
Is THPS better than glutaraldehyde?
Neither is universally better – both are non-oxidising biocides. THPS is especially used in oilfield injection water; glutaraldehyde is fast-acting. They are often combined.
Can THPS be used with oxidising biocides?
Yes – in a programme where a non-oxidising biocide (THPS) complements an oxidising one.
Which biocide controls sulphate-reducing bacteria?
Both THPS and glutaraldehyde are used for SRB control in oilfield systems; dosing is set by field testing.
Do quaternary ammonium biocides replace THPS?
They have a different (surface-active) mode; they are used alongside, not as a straight replacement.
How is dosing set?
On the active content and the measured microbial load, confirmed by microbial testing.
Related reading
- THPS (CAS 55566-30-8): properties, production and applications
- THPS for oilfield and industrial water treatment
- Glutaraldehyde (CAS 111-30-8): properties, manufacturing and applications
- THPS (CAS 55566-30-8) – product page
PolyBlueChem supplies THPS (CAS 55566-30-8) for water treatment, with per-batch COA and SDS. Contact us with your application and tonnage.