I have done a exhaustive research for Microwave ovens and has collected very critical information for all Microwave buyers / existing users.
Below is the excerpt from report published by Food and Drug Administration, US Federal Government. These regulations / norms are applicable for all Microwave manufacturers.
# Microwave oven means a device designed to heat, cook, or dry food through the application of electromagnetic energy at frequencies assigned by the Federal Communications Commission in the normal ISM heating bands ranging from 890 megahertz to 6, 000 megahertz.
# Requirements -(1)Power density limit. The equivalent plane-wave power density existing in the proximity of the external oven surface shall not exceed 1 milliwatt per square centimeter at any point 5 centimeters or more from the external surface of the oven, measured prior to acquisition by a purchaser, and, thereafter, 5 milliwatts per square centimeter at any such point.
# How strong is the Quality of Magnetron and Cavity used which ensures radiation will not widespread outside the cavity box.
# What Norms and Regulation respective Manufacturer vendor is following manufacturing and distributing microwave products on respective country soil.
# What kind of Certifications vendors have absorbed on microwave products that are available on country Soil.
FYI: Link below refers to FDA Standards set applicable for any Microwave Oven Manufacturer,
https://accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=1030&showFR=1
Believe it or not, I have interacted with every Brand through phone, email, fax, personally walk in: SAMSUNG, IFB, LG, ONIDA, SIEMENS, PANASONIC, WHIRLPOOL ETC. NONE OF THEM HAVE ANY CERTIFICATIONS, LICENSE RIGHTS & NORMS, FDA CERTIFICATION, ADOPTED STANDARDS FOR MAGNETRON WHICH GIVES RELAXATION TO A CONSUMER THAT MICROWAVE IS COMPLETELY SAFE FOR HUMAN CONSUMPTION.
ALL OF THEM ARE JUST MAKING MICROWAVES AND SELLING IT IN INDIA MARKET BLINDLY.