Accepta 6404 – DBNPA Based Non Oxidising Biocide

Accepta 6404: 2.5 kg jars (4 jars per case)

Suitable for use with Accepta Ultra Dissolver Boards

Description below


Broad Spectrum Non Oxidising Biocide:

Active Ingredients:  2,2-Dibromo-3-NitriloPropionamide (DBNPA) 98% min.assay.  Highly effective against a wide range of common water borne organisms with proven efficacy against Legionella. Accepta 6404 will control these organisms and help to control microbiological fouling.

Accepta 6404 is designed for use in open cooling water systems, chilled water systems, process systems and other industrial water systems. DBNPA has proven efficacy against pathogenic microorganisms including Legionella, at levels required by the system, L8 (HS(G) 274), system water type, along with risk assessment data.

Accepta 6404 degrades rapidly and naturally at increased pH & temperature levels and as such Accepta 6404 is the product of choice for systems operating under strict environmental and discharge regulations.

The ultimate degradation products are carbon dioxide, ammonia, & bromide ion. Increasing cooling water alkalinity presents a problem for most water treatment biocides. However, for Accepta 6404 even at higher pH values, rapid & effective microbial control is achieved before any significant degradation occurs. Ideal for quick, antimicrobial activity, but rapid degradation of the microbiocide for minimal environmental impact.

Recommended contact time for biological control is 4 hours minimum at the target residual.


Accepta 6404 application rates for industrial recirculating cooling water systems will depend upon the conditions of the system prior to treatment initiation.

1.02g of Accepta 6404 will add 1ppm of DBNPA to 1000lt of system water.

Target Residual (ppm) x 1.02 x System Volume (m3) = dose required (g)

  • DBNPA shot dosed at 2-5ppm active is proven to control legionella in the planktonic phase with a contact time of 2-3 hours.
  • DBNPA shot dosed at 10-15ppm active is proven to control both planktonic and sessile legionella colonies with a contact time of 4-6 hours
  • DBNPA dosed to maintain a constant level of 1-2ppm active is proven to be effective at controlling legionella in the planktonic and sessile phase.

Accepta 6404 can be tested and controlled by ATP, DBNPA biocide test kit or by measuring direct control through colony counts.


Appearance:                            Solid – white/yellow powder

Odour:                                     characteristic/pungent


Accepta 6404 should be in a cool dry area.  Properly stored, the product will remain effective for 24 – 36 months.  Consult Safety Data Sheet for further information.


Accepta 6404 is available in 2.5 kg jars (4 jars per case)


Feed Accepta 6404 using an Accepta board system.

Available in three types:

  • Gravity Fed – No pump needed, requires controller relay or timer
  • Electronic Level Control – Pump needed
  • Mechanical – Pump needed

It is always advisable to carry out a ‘Control Of Substances Hazardous to Health’ (COSHH) assessment before use.

For further technical assistance concerning Accepta 6404 please contact Accepta.

Safety, Storage & Handling

For full details concerning safety precautions, storage and handling procedures for this product please refer to the latest Safety Data Sheet. To request the latest MSDS for this product please fill out the form below.

    Additional information

    Weight 25 kg