CONCENTRATION OF RISK

3 Months Ended

Mar. 31, 2023

19. CONCENTRATION OF RISK:

Revenues and accounts receivable from the Company's largest customers were as follows (in thousands):


	% of Total Revenue for the Three Months Ended March 31,		Accounts Receivable as of
Customer	2023	2022	March 31, 2023
A	30%	40%	$	8,780
B	26%	27%	$	34,100
C	21%	15%	$	29,887

Revenues from outside of North America represented approximately 97% for both three-month periods ended March 31, 2023 and 2022. Revenues by geographic area are as follows (in thousands):


	Three Months Ended March 31,
Country	2023		2022
South Korea	$	66,060	$	89,687
China		57,427		55,400
Japan		1,647		1,053
Other non-U.S. locations		1,337		300
Total non-U.S. locations		126,471		146,440
United States		3,996		4,030
Total revenue	$	130,467	$	150,470

The Company attributes revenue to different geographic areas on the basis of the location of the customer.

Long-lived assets (net), by geographic area are as follows (in thousands):


	March 31, 2023		December 31, 2022
United States	$	115,915	$	117,255
Ireland	$	23,845	$	20,270
Other		5,521		5,920
Total long-lived assets	$	145,281	$	143,445

Substantially all chemical materials were purchased from one supplier. See Note 13 for further explanation.