Cover - shares	3 Months Ended
	Mar. 31, 2021	May 17, 2021
Cover [Abstract]
Entity Registrant Name	NANOPHASE TECHNOLOGIES Corp
Entity Central Index Key	0000883107
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2021
Entity File Number	000-22333
Entity Incorporation, State Code	DE
Current Fiscal Year End Date	--12-31
Entity Reporting Status Current	Yes
Entity Interactive Data Current	Yes
Entity Small Business	true
Entity Filer Category	Non-accelerated Filer
Entity Emerging Growth	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		48,336,877
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2021