Per the SINGAPORE CONSUMER PROTECTION (SAFETY REQUIREMENTS) REGISTRATION SCHEME an "adapter" is required to be tested and certified for use in the country. An "adapter" is defined by the regulator as "A device designed to supply a.c. or d.c. power from an a.c. or d.c. source, either by itself or as part of an accessory, for applications such as computers, telecommunication equipment, home entertainment equipment or toys."
The applicable standards are (applicable for electrical appliances) IEC 61558-2-6: 2009 or IEC 61558-2-6: 1997 (valid till 31 December 2014) or IEC 61558-2-16: 2009 (applicable for electronic appliances) IEC 60065: 2001
(applicable for computer / telephonic appliances) IEC 60950-1: 2005 or IEC 60950-1: 2001 (valid till 31 December 2014) (applicable for shavers) IEC 60335-2-8: 2002
(applicable for battery chargers) IEC 60335-2-29: 2002 with A1 or IEC 60335-2-29: 2004
(applicable for LED lightings) IEC 61347-2-13: 2006 (applicable for table/standing lamps) IEC 60598-2-4: 1997 1
Below is a real time product offering from GlobTek for Power supplies with Singapore certification: