How safe is it to mount an ext3 partition?

[José de Paula Rodrigues]

How safe is it to mount an ext3 partition from a current (up-to-date
Debian Unstable with kernel 2.6) Linux distro? About an year ago I had
problems mounting my ext3 partition as ext2, even as read-only; it led
to the corruption of the filesystem. Can it be safely done now, with
an up-to-date 5.3 FreeBSD?

Thanks for your help.