Product Knowledge

Bronopol for Paper Mill & Pulp Processing

Paper mills and pulp processing systems circulate large volumes of warm, nutrient-rich process water that readily supports bacterial slime formation. Bronopol has been used as an antimicrobial in these systems since its early industrial adoption. This guide covers its role in paper mill slime control.

Published 2026-01-20Updated 2026-07-27By Vasudev Chemo Pharma Technical TeamReviewed by Vasudev Chemo Pharma Formulation & Regulatory Affairs Team, Industrial Chemistry, Biocide Formulation

Why Do Paper Mills Need Slime Control Biocides?

Paper mill process water systems circulate warm, nutrient-rich water containing cellulose fibres and additives that readily support bacterial slime formation. Uncontrolled slime causes web breaks, product quality defects, and machine runnability problems, which Bronopol helps prevent.

Bronopol was among the antimicrobials adopted as an industrial biocide in paper mill systems following its 1984 US registration for use as an industrial bactericide, slimicide, and preservative, alongside its adoption in oil exploration, production facilities, and cooling water disinfection. Bacterial slime in paper mill systems typically forms in stock chests, white water systems, and other areas where process water recirculates and pools, and can lead to visible spots and holes in finished paper, web breaks during production, and reduced machine efficiency if uncontrolled.

How Is Bronopol Applied in Paper Mill Systems?

Dosing in paper mill systems is process-specific, targeting stock chests, white water systems, and other areas prone to bacterial slime accumulation. Dosage and application points should be established with your mill's process engineering team based on system volume and bioburden.

As with other continuously recirculating industrial water systems, Bronopol dosing in paper mills is typically scheduled or continuous, calibrated to system volume and monitored bacterial load, rather than a single-batch addition as used in cosmetic formulations. Because pulp and paper process chemistry often involves a range of other additives (sizing agents, retention aids, defoamers), compatibility should be confirmed with your mill's chemical supplier before introducing or adjusting a Bronopol dosing programme.
Common slime-control problem areas in paper mill systems
System areaBacterial contamination riskImpact if untreated
Stock chestsHigh — nutrient-rich pulp stockSlime deposits, stock quality defects
White water systemsHigh — recirculated process waterWeb breaks, machine downtime
Approach flow systemsModerate to highReduced runnability, product defects

Frequently asked questions

Why do paper mills need biocide treatment?+
Paper mill process water systems circulate warm, nutrient-rich water that readily supports bacterial slime formation, which can cause web breaks, product quality defects, and reduced machine efficiency. Bronopol helps control this bacterial growth.
Where in a paper mill is Bronopol typically applied?+
Bronopol is typically applied to stock chests, white water systems, and other areas where process water recirculates and pools, encouraging bacterial slime accumulation if left untreated.
How is Bronopol dosed in paper mill systems?+
Dosing is process-specific and typically scheduled or continuous, calibrated to system volume and monitored bacterial load. Work with your mill's process engineering team to establish an appropriate dosing programme.

Sources

  1. PubChem — Bronopol compound summary