The UV absorption spectrum of pyridine and its gas phase reactions with OH radicals and O-3 were investigated. UV absorption cross-sections were determined by using a D-2-lamp system in the range 200-350 nm. The kinetic studies were carried out at room temperature and atmospheric pressure of purified air. The rate coefficient for the reaction of pyridine with OH was determined relative to that with acetone while that with O-3 was measured under pseudo first order conditions. The rate coefficients obtained are (in cm(3) molecule(-1) s(-1)): k(OH + pyridine) = (5.40 +/- 0.80) x 10(-13) and k(O-3 + pyridine) = (3.28 +/- 1.70) x 10(-20). (C) 2016 Elsevier B.V. All rights reserved.