The report describes the results of sampling for carcinogens and respiratory sensitisers at ten large processing plants. The measurement strategy used was sufficiently broad in scope to take into account the presence of respiratory sensitisers and respiratory irritants as well as carcinogens. The findings demonstrate that compliance with HSE guidance achieves adequate prevention and control of exposure in the common thermoplastic processes considered. This report will be helpful to smaller plants operated by small and medium enterprises who undertake the same processes albeit on a smaller scale.