Property, plant and equipment (Tables)

12 Months Ended

Dec. 31, 2023

Property, plant and equipment

Schedule of elements of property, plant and equipment

					Estimated
December 31,	2023		2022		Lives
(in thousands)
Property, plant and equipment
- Land	$	1,255	$	1,255
- Land improvements		319		319	6-10 years
- Buildings		1,446		1,446	25-39 years
- Building improvements		3,467		3,396	25-39 years
- Cylinders		13,220		13,315	15-30 years
- Equipment		29,397		27,258	3-10 years
- Equipment under capital lease		315		315	5-7 years
- Vehicles		1,790		1,773	3-5 years
- Lab and computer equipment, software		3,233		3,103	2-8 years
- Furniture & fixtures		933		840	5-10 years
- Leasehold improvements		865		852	3-5 years
- Construction-in-Progress		2,844		3,533
Subtotal		59,084		57,405
Less: Accumulated depreciation		(39,709)		(36,837)
Total	$	19,375	$	20,568