# Quantitative assessment of Benzalkonium residues in abattoir wastewater and evaluation of disinfectant application practices in Western Thailand

## TL;DR

This study found benzalkonium chloride contamination in abattoir wastewater in Thailand, highlighting environmental risks and the need for better safety practices.

## Contribution

The study quantifies benzalkonium residues in abattoir wastewater and evaluates disinfectant usage practices in Western Thailand.

## Key findings

- BAC residues were detected in all abattoirs, including 40% that did not report using BAC-based disinfectants.
- Large-scale facilities discharged wastewater into public waterways, posing environmental risks.
- Safety practices like training and protective equipment were significantly associated with abattoir scale.

## Abstract

To assess benzalkonium chloride (BAC) contamination in abattoir wastewater and evaluate disinfectant usage practices in Western Thailand.

Wastewater samples and questionnaire data were collected from 20 pig and poultry abattoirs. BAC analogues were detected using ultra-high-performance liquid chromatography with diode array detection. Associations between abattoir scale and safety practices were analyzed using Fisher’s exact test, with effect sizes expressed as Cramer’s V.

BAC residues were identified in all abattoirs, including 40% that reported not using BAC-based disinfectants. Four large-scale facilities discharged wastewater into public waterways, posing environmental risks. Significant associations were found between abattoir scale and safety measures: safety training (Cramer’s V = 0.59), personal protective equipment availability (0.57), and spill kit preparedness (0.89). Large-scale facilities adhered to these measures, while small and medium operations showed limited compliance. Although smaller facilities did not discharge into public areas, insufficient safety practices may contribute to BAC accumulation.

BAC residues are widespread in abattoir wastewater. Strengthened regulatory oversight, systematic monitoring, and routine safety training are essential to mitigate environmental and occupational hazards.