Objectives South African herbicide sprayers removing alien vegetation are exposed to a myriad of herbicides resulting in acute and chronic health risks. Workers often are not willing to participate in standard biological monitoring assessments through the provision of blood and urine in order to assess these potential risks. Furthermore, laboratory capacity to analyse herbicides residues are limited. The study aim was to document workers’ exposure risks in order to develop health interventions using an observation exposure assessment method.

Method Researchers observed three teams, each comprised of 10 workers and one contractor, from February to June 2012. An observational guide was developed and findings were recorded in a field journal. Observations were supported with video and photographic materials.

Results The on-site observations revealed workers lack of PPE compliance, behaviours that increased their exposure risks, and non-compliance with work standards. Workers’ exposure risks were compounded by harsh working conditions, high turnover rates of workers, worker’s low risk perceptions, power struggles, and gendered beliefs of masculinity being threatened by PPE use.

Conclusions In some circumstances researchers are unable to use biological monitoring methods to establish pesticide exposure risks for workers in developing countries. Observation methods are a viable alternative method, particularly for informing worker risk reduction interventions.