FORMALDEHYDE MEASUREMENT IN EMISSIONS FROM PRESS BOARD AND BONDED FIBRE PRODUCTION

Introduction

Formaldehyde is a known carcinogen and its concentrations have to be minimized in industrial emissions. Sectors where formaldehyde containing formulations are applied include mineral wool forming by resin impregnation and the manufacturing of pressed boards. For stack emissions typically limit values of 20 mg/Nm³ are imposed and the test methods have to be validated in this range. In cases where a limit total emission factor expressed as quantity of formaldehyde released per unit of product, e.g. in kg/m³, is specified, additonally the determination of diffuse emissions of formaldehyde is required. This paper describes validation work on formaldehyde measurement in gases and illustrates problems of incomplete recovery of formaldehyde when the DNPH method is used in stack gas sampling. The tests confirmed that the EPA 316 method with spectrophotometrical analysis is suited to deliver accurate results in this range.