While journals are in large part the main venue for academic publishing, conferences are heavily utilized in some other venues. It seems from the venues I have been around, there is a separation between these two types of venues in regards to ethical review for publication.
While PLOS ONE has a specific statement about this:
Researchers submitting studies involving human participants must meet the following requirements:
Obtain prior approval for human subjects research by an institutional review board (IRB) or equivalent ethics committee(s) ...
All submissions describing clinical research and/or research on human subjects will be checked by journal staff to ensure that the requirements above are met. Failure to meet requirements may be grounds for rejection. If issues are discovered after publication, we may issue a correction or retraction as appropriate.
Organizations like COPE, which seem to be used by many groups (including ACM) do not seem to have ethical human subject studies under their 'Ethics' category.
Is receiving IRB approval only a matter that a university should care about? If an organization includes in proceedings or issue a paper that did not have IRB approval, is it only up to the university or author to retract this, or does the organization have a responsibility to do this?