No blockchain is legal tender in Europe, including Ireland.

If an ICO falls under securities regulation this document details the ergulations that it may have to comply with, as listed below.

• The Prospectus Directive: the securities token will subject to publication of a prospectus which must be approved before the token can be offered.
• The Markets in Financial Instruments Directive (MiFID): if the firm 1) provides services to clients around financial instruments 2) the organized trading of financial instruments, it will be subject to MiFID regulations. The MiFID is a large suite of regulations designed to protect investors in financial markets. A detailed summary of MiFID requirements can be found here. It is recommend to consult with a lawyer if your firm’s activities seem to fall under MiFID’s regulation.
• Fourth Anti-Money Laundering Directive: “The Directive requires firms to carry out due diligence on customers and to have in place appropriate record-keeping and other internal procedures. Firms have an obligation to report any suspicious activity and to co-operate with any investigations by relevant public authorities.”
• Alternative Investment Fund Managers Directive: This directive regulates alternative investment fund managers. A small number of blockchain projects may be considered alternative investment funds. If this applies to your firm, see this source for detail on the regulations.

Sources:

• Overview of MiFID II Regulations
• ESMA alerts firms involved in Initial Coin Offerings (ICOs) to the need to meet relevant regulatory requirements
• European Securities and Markets Authority: Report - The Distributed Ledger Technology Applied to Securities Markets
• Blockchain and Virtual Currency Regulation in the EU
• Alternative Investment Fund Managers Directive: Overview