Samples of Norway spruce were treated with alkyd resin lacquer or glaze varnish and 4.5 mg/100cm² (a) cypermethrin, (b) fenvalerate, (c) lindane or (d) natural pyrethrum. After 180 days, recovery rate of (a) was 95%, (b) 60%, and (c) 35%; after 10 days, recovery rate of (d) was 0%. Penetration tests, surface wiping tests with methanol, and water exposure tests are reported on samples treated with (a). Overall it is concluded that thesynthetic pyrethroids (a) and (b) exhibit high stability and long-term retention; in contrast to lindane, there is negligible risk of pollution of indoor environments because these compounds do not volatilize to the gas phase and their degradation products are non-toxic. -- AATA