Legal in most countries with permits

Needs to comply with EPA/ocean dumping regulations

The ashes must be processed to be environmentally safe

Legal in most countries

Must be pre-approved green burial grounds; some US states mandate vaults or embalming which limits access. 

This is a legal and standard practice, but the use of dry ice is uncommon. 

Refrigeration is regulatory

Dry Ice: very expensive and still requires some chemical usage to be legal deemed safe. 

Mostly illegal in majority of countries

Restricted because of public health and sanitation laws, and may violate body disposal regulations. 

Legal in some countries, not in most US states

Requires state funeral board approval

Has lots of opposition from religious groups

Legal for body donation with prior consent and signed  contracts

This is not recognized as a legal burial

Not officially recognized and mostly illegal

Legal contracts prior to death is required