Formaldehyde

A former disinfectant and sterilant for use in cleaning equipment but also for the control of the more severe Fairy rings: grade 1 (Marasmius oreades), where the remaining excavated pit from the contaminated soil and turf was treated with formaldehyde to hopefully kill off any potential remaining fungal presence. Typically, a 40% concentration was used, the area well-watered in and covered over with a polythene or waterproof tarpaulin and left for 10-14 days before being removed to maximise the sterilising effect.