my $to_entitise =
   q{<>&"'} .              # Unsafe for HTML
   q{\x{100}-\x{1FFFFF}};  # Not present in iso-8859-1

my $decoded_text = decode('UTF-8', $utf8_text);
my $decoded_html = encode_entities($decoded_text, $to_entitise);
my $latin1_html = encode('iso-latin-1', $decoded_html);