Exhibit 21.1

SUBSIDIARIES OF PQ GROUP HOLDINGS INC.

ENTITY						JURISDICTION
PQ Group Holdings Inc.						Delaware
PQ Holdings Inc.						Delaware
CPQ Midco I Corporation						Delaware
PQ Corporation						Pennsylvania
PQ Holdings I Limited						United Kingdom
PQ Intermediate Limited						United Kingdom
PQ Germany GmbH						Germany
PT PQ Silicas Indonesia						Indonesia
PQ Sweden A.B.						Sweden
PQ Finland Oy						Finland
PQ Silicas Holdings South Africa Pty Ltd.						South Africa
PQ Silicas South Africa Pty Ltd.						South Africa
Quaker Chemicals South Africa Pty Ltd. 1						South Africa
PQ International Holdings Inc.						Delaware
PQ Netherlands Holding LLC						Delaware
PQ Silicas Asia Pacific Pte Ltd.						Singapore
PQ Silicates Ltd. 2						Taiwan
PQ International C.V.						Netherlands
PQ Netherlands Cooperative LLC						Delaware
PQ International Coöperatie U.A.						Netherlands
PQ Silicas Brazil Ltda.						Brazil
PQ Acquisition B.V.						Netherlands
PQ Canada Company						Canada
PQ Australia LLC						Delaware
NSL Australia Company						Canada
NSL Canada Company						Canada
National Silicates Partnership						Canada
PQ Europe Coöperatie U.A.						Netherlands
PQ Europe ApS						Denmark
PQ Silicas B.V.						Netherlands
PQ Zeolites B.V.						Netherlands
Zeolyst C.V. 3						Netherlands
PQ Italy S.r.l.						Italy
PQ France S.A.S.						France
PQ Silicas UK Limited						United Kingdom
PQ Chemicals (Thailand) Limited						Thailand
PQ Holdings Mexicana, S.A. de C.V. 4						Mexico
Silicatos y Derivados, S.A. de C.V.						Mexico
PQ China (Hong Kong) Limited						Hong Kong
PQ Mexico Holdings B.V.						Netherlands
PQ Mexico S. de R.L. de C.V.						Mexico
Zeolyst International 5						Kansas
Eco Services Operations Corp.						Delaware
PQ Asia Inc.						Delaware
KILT, LLC 6						Delaware
Delpen Corporation						Delaware
Commercial Research Associates, Inc.						Pennsylvania
PQ Systems Incorporated						Pennsylvania
PQ Export Company						Delaware
PQ International, Inc.						Pennsylvania
Philadelphia Quartz Company						Pennsylvania

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1			Represents a joint venture company of which the registrant indirectly owns 49% of the voting equity.
2			Represents a joint venture company of which the registrant indirectly owns 50% of the voting equity.
3			Represents a joint venture company of which the registrant indirectly owns 50% of the voting equity.
4			Represents a joint venture company of which the registrant indirectly owns 80% of the voting equity.
5			Represents a joint venture company of which the registrant indirectly owns 50% of the voting equity.
6			Represents a joint venture company of which the registrant indirectly owns 72.5% of the voting equity.