Australia Model Code of Practice: Managing Risks of Hazardous Chemicals in the Workplace 3.3d: 3.3 Act on exposure results: review at half the standard and protect sensitised workers

Where monitoring shows concentrations approaching the exposure standard, for example above half of it, control measures should be reviewed. Exposure below the standard may still affect sensitive workers because standards are not a no-effect level, so exposure to any hazardous chemical, including those without a standard, should be kept as low as reasonably practicable. Chemicals with a skin notation can be absorbed through the skin and biological monitoring can help assess total exposure. Sensitisers such as isocyanates can trigger reactions well below the standard once a worker is sensitised, so for a sensitised worker the standard stops being the relevant limit and controls such as improved engineering or job rotation away from exposure should be put in place.