WIll 2 - butanone oxime be harmful to frogs once cured and completey set and left for 48hrs with dirt over the top of it??
Obviously the layer will be foam, then the brown silicone then the dirt.... this is the link: Interior and Exterior Frame Silicone Sealant - Brown from Homebase.co.uk
If thats no good there is another one that says it has minimul VOC (cant guarantee there will be none i guess.. but can any have that guarantee!?): http://www.diy.com/diy/jsp/bq/nav.jsp?action=detail&fh_secondid=11348635&fh_loca tion=//catalog01/en_GB/categories%3C{9372013}/categories%3C{9372031}/categories%3C{9372100}/specificationsProductType=sealants