Note 2 - Summary of Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2022

Notes Tables

Schedule of Cash and Cash Equivalents [Table Text Block]

	June 30, 2022		December 31, 2021
BioLargo, Inc. and subsidiaries	$	1,216	$	941
Clyra Medical Technologies, Inc.		10		21
Total	$	1,226	$	962

Schedules of Concentration of Risk, by Risk Factor [Table Text Block]

	June 30, 2022			June 30, 2021
Customer A		35	%		<10	%
Customer B		17	%		<10	%
Customer C		10	%		<10	%
Customer D		<10	%		22	%
Customer E		<10	%		19	%
Customer F		<10	%		11	%

	June 30, 2022			December 31, 2021
Customer A		11	%		<10	%
Customer B		31	%		<10	%
Customer G		15	%		<10	%
Customer H		<10	%		32	%
Customer I		<10	%		12	%

Schedule of Inventory, Current [Table Text Block]

	June 30, 2022		December 31, 2021
Raw material	$	116	$	108
Finished goods		140		133
Total	$	256	$	241

Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	2022						2021
	Non Plan			2018 Plan			Non Plan			2018 Plan
Risk free interest rate		2.32	%	2.32	–	2.98%		1.73	%	0.93	–	1.73%
Expected volatility		117	%	116	–	117%		124	%	123	–	124%
Expected dividend yield		—			—			—			—
Forfeiture rate		—			—			—			—
Life in years		10			10			10			10