Note 2 - Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2022

Notes Tables

Schedule of Cash and Cash Equivalents [Table Text Block]

	September 30, 2022		December 31, 2021
BioLargo, Inc. and subsidiaries	$	1,251	$	941
Clyra Medical Technologies, Inc.		17		21
Total	$	1,268	$	962

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

	September 30, 2022			September 30, 2021
Customer A		44	%		<10	%
Customer B		14	%		<10	%
Customer C		<10	%		12	%
Customer D		<10	%		14	%
Customer E		<10	%		11	%

	September 30, 2022			December 31, 2021
Customer A		13	%		<10	%
Customer B		15	%		<10	%
Customer F		11	%		<10	%
Customer G		<10	%		32	%
Customer H		<10	%		12	%

Schedule of Inventory, Current [Table Text Block]

	September 30, 2022		December 31, 2021
Raw material	$	123	$	108
Finished goods		137		103
Total	$	260	$	241

Schedule of Other Assets, Noncurrent [Table Text Block]

	September 30, 2022		December 31, 2021
Patents	$	34	$	34
Security deposits		35		35
Tax credit receivable		54	$	-
Total	$	123	$	69

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	–	3.83%	2.32	–	3.83%		1.73	%	0.93	–	1.73%
Expected volatility	115	–	117%	115	–	117%		124	%	121	–	124%
Expected dividend yield		—			—			—			—
Forfeiture rate		—			—			—			—
Life in years		10			10			10			10