Workers’ compensation expense consists of the following components:



	Three Months Ended September 30,						Nine Months Ended September 30,
	2018			2017			2018		2017
	(In thousands)
Self-insured occupational disease benefits:
Service cost	$	1,860		$	1,558		$	5,580	$	4,675
Interest cost⁽¹⁾	1,196			1,169			3,585		3,506
Curtailments	$	—		$	(4,660	)	$	—	$	(4,660	)
Total occupational disease	$	3,056		$	(1,933	)	$	9,165	$	3,521
Traumatic injury claims and assessments	(2,069		)	3,077			3,130		8,487
Total workers’ compensation expense	$	987		$	1,144		$	12,295	$	12,008

During the third quarter of 2018, the Company recorded a $4.0 million reduction to its workers’ compensation liability with the offset to “Cost of Sales” in the Condensed Consolidated Income Statements. The liability was revalued using current claims data discounted at 3.08%.

(1) In accordance with the adoption of ASU 2017-07, “Compensation-Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost,” these costs are recorded within Nonoperating expenses in the Condensed Consolidated Income Statements on the line item “Non-service related pension and postretirement benefit costs.” For additional information about the adoption of the standard, see Note 2, “Accounting Policies” in the Condensed Consolidated Financial Statements.