Ferric phosphate is a stable, non-volatile solid that does not readily dissolve in water. This property minimizes ferric phosphate’s dispersal beyond where it is applied. It is highly unlikely that ferric phosphate or its breakdown products will persist or become highly concentrated in the environment. When Ferramol is applied as a molluscicide, the amount of additional iron and phosphorus added to the soil is negligible compared to the amount of iron and phosphorus already present in soil.
Ferramol is a stomach poison. It therefore works in a different way to metaldehyde which works by dehydration. Once the pellet has been ingested feeding ceases immediately and the slug or snail dies 3 – 6 days later. Unlike metaldehyde, as the mucus production is not affected, the slugs and snails are able to move away to die so there are often no dead slugs or snails to be seen in the treated area.
The pellets period of persistence will depend on the level of wetness but in general an application will
last a number of weeks. However, if 25 mm of rain falls and it remains damp then replacement pellets may be required 7 days later.
Ferramol has a low impact on the environment. Ferric phosphate, the active ingredient in Ferramol, has extremely low mammalian toxicity. It is virtually harmless to higher animals. Carabid beetles, earthworms, bees, birds and other beneficial organisms are not affected. When it biodegrades it releases iron and phosphorus into the soil which are essential plant nutrients. Although there is no aquatic toxicity from
Ferramol as a matter of good practice it is better to avoid its use around water courses.
Ferramol is allowed under EU regulation 2092/91 (the minimum legal standards for organic production).
However, Soil Association licensees have to obtain prior permission and submit justification for using it.