Solvay SA

Declaration of Voting Results & Voting Rights Announcements • Mar 20, 2018

PARTICIPATION NOTIFICATION BY SOLVAC SA

Brussels, Tuesday March 20, 2018, 8h00 --- According to the Belgian transparency legislation in force (Law of May 2, 2007), SOLVAC SA, located at Rue des Champs Elysées 43 – 1050 Brussels – Belgium, has notified Solvay SA that on:

• March 12, Solvay Stock Option Management Sprl (SSOM) crossed downwards the statutory declaration threshold of 3% of the existing voting rights emitted by Solvay SA, for a total of 2.997% (2.327% of direct voting rights + 0.67% of other financial instruments), whereby the combined holding by Solvac and SSOM reached 33.70% of the existing voting rights;
• March 14, SSOM crossed upwards the statutory declaration threshold of 3% of the existing voting rights emitted by Solvay SA, for a total of 3.007% (2.337% of direct voting rights + 0.67% of other financial instruments), whereby the combined holding by Solvac and SSOM reached 33.71% of the existing voting rights.

SOLVAC SA is presumed to exercise de facto control over Solvay SA, and therefore SSOM, on the basis of Article 5, §3, 2nd paragraph of the Belgian companies code.

The declaration by SOLVAC SA is published in the Investor Relations Section of Solvay's website.

1 st Notification received on March 15, 2018

• Reason for the notification: Disposal of voting securities or voting rights
• Notified by: SOLVAC SA (Rue de Champs Elysées 43 1050 Brussel Belgium)
• Persons subject to the notification requirement:

Name	Address (for legal entities)
SOLVAC SA	Rue de Champs Elysées 43 – 1050 Brussels – Belgium
SOLVAY SA	Rue de Ransbeek 310 – 1120 Neder-Over-Heembeek – Belgium
SOLVAY CHEMICALS INTERNATIONAL SA	Rue de Ransbeek 310 – 1120 Neder-Over-Heembeek – Belgium
SOLVAY STOCK OPTION MANAGEMENT SPRL	Rue de Ransbeek 310 – 1120 Neder-Over-Heembeek – Belgium

• Date on which the threshold is crossed: March 12, 2018
• Threshold crossed: 3% downward (lowest declaration threshold)
• Denominator: 105,876,416
• Notification details: The voting rights and equivalent financial instruments total 35,684,788 voting rights or 33.70%.

A) Voting rights	Previous notification	After the transaction
	# of voting rights	# of voting rights		% of voting rights
Holders of voting rights		Linked to securities	Not linked to the securities	Linked to securities	Not linked to the securities
SOLVAC SA	32,511,125	32,511,125		30.71%
SOLVAY SA	0	0		0.00%
SOLVAY CHEMICALS INTERNATIONAL SA	0	0		0.00%
SOLVAY STOCK OPTION MANAGEMENT SPRL	2,472,641	2,463,789		2.327%
Subtotal		34,974,914	0	33.03%	0.00%

Ce communiqué de presse est également disponible en français. - Dit persbericht is ook in het Nederlands beschikbaar.

B) Equivalent financial instruments	After the transaction
Holders of equivalent financial instruments	Type of financial instrument	Expiration date	Exercise period or date	# of voting rights that may be acquired if the instrument is exercised	% of voting rights	Settlement
SOLVAY STOCK OPTION MANAGEMENT SPRL	Call option	16/03/2020		150,000	0.14%	Physical
SOLVAY STOCK OPTION MANAGEMENT SPRL	Call option	24/03/2021		106,400	0.10%	Physical
SOLVAY STOCK OPTION MANAGEMENT SPRL	Call option	23/02/2022		95,760	0.09%	Physical
SOLVAY STOCK OPTION MANAGEMENT SPRL	Call option	24/02/2023		87,214	0.08%	Physical
SOLVAY STOCK OPTION MANAGEMENT SPRL	Call option	23/02/2024		190,500	0.18%	Physical
SOLVAY STOCK OPTION MANAGEMENT SPRL	Call option	21/02/2025		20,000	0.02%	Physical
SOLVAY STOCK OPTION MANAGEMENT SPRL	Call option	21/02/2025		20,000	0.02%	Physical
SOLVAY STOCK OPTION MANAGEMENT SPRL	Call option	24/02/2025		20,000	0.02%	Physical
SOLVAY STOCK OPTION MANAGEMENT SPRL	Call option	24/02/2025		20,000	0.02%	Physical
Subtotal				709,874	0.67%

Chain of control

Solvay Stock Option Management SPRL is owned by Solvay Chemicals International SA (99.99%) and by Solvay Participations Belgique SA, which are themselves owned by Solvay SA (99.99%) and Financière Solvay SA.

Solvac SA is presumed to exercise de facto control over Solvay SA on the basis of Article 5, §3, 2nd paragraph of the Belgian companies code.

2 nd Notification received on March 15, 2018

• Reason for the notification: Acquisition of voting securities or voting rights
• Notified by: SOLVAC SA (Rue de Champs Elysées 43 1050 Brussel Belgium)
• Persons subject to the notification requirement:

Name Address (for legal entities)
SOLVAC SA	Rue de Champs Elysées 43 – 1050 Brussels – Belgium
SOLVAY SA	Rue de Ransbeek 310 – 1120 Neder-Over-Heembeek – Belgium
SOLVAY CHEMICALS INTERNATIONAL SA	Rue de Ransbeek 310 – 1120 Neder-Over-Heembeek – Belgium
SOLVAY STOCK OPTION MANAGEMENT SPRL	Rue de Ransbeek 310 – 1120 Neder-Over-Heembeek – Belgium

• Date on which the threshold is crossed: March 14, 2018
• Threshold crossed: 3% upwards (lowest declaration threshold)
• Denominator: 105,876,416
• Notification details: The voting rights and equivalent financial instruments total 35,694,948 voting rights or 33.71%.

A) Voting rights	Previous notification	After the transaction
	# of voting rights	# of voting rights		% of voting rights
Holders of voting rights		Linked to securities	Not linked to the securities	Linked to securities	Not linked to the securities
SOLVAC SA	32,511,125	32,511,125		30.71%
SOLVAY SA	0	0		0.00%
SOLVAY CHEMICALS INTERNATIONAL SA	0	0		0.00%
SOLVAY STOCK OPTION MANAGEMENT SPRL	2,463,789	2,473,949		2.34%
Subtotal		34,985,074	0	33.04%	0.00%

B) Equivalent financial instruments	After the transaction
Holders of equivalent financial instruments	Type of financial instrument	Expiration date	Exercise period or date	# of voting rights that may be acquired if the instrument is exercised	% of voting rights	Settlement
SOLVAY STOCK OPTION MANAGEMENT SPRL	Call option	16/03/2020		150,000	0.14%	Physical
SOLVAY STOCK OPTION MANAGEMENT SPRL	Call option	24/03/2021		106,400	0.10%	Physical
SOLVAY STOCK OPTION MANAGEMENT SPRL	Call option	23/02/2022		95,760	0.09%	Physical
SOLVAY STOCK OPTION MANAGEMENT SPRL	Call option	24/02/2023		87,214	0.08%	Physical
SOLVAY STOCK OPTION MANAGEMENT SPRL	Call option	23/02/2024		190,500	0.18%	Physical
SOLVAY STOCK OPTION MANAGEMENT SPRL	Call option	21/02/2025		20,000	0.02%	Physical
SOLVAY STOCK OPTION MANAGEMENT SPRL	Call option	21/02/2025		20,000	0.02%	Physical
SOLVAY STOCK OPTION MANAGEMENT SPRL	Call option	24/02/2025		20,000	0.02%	Physical
SOLVAY STOCK OPTION MANAGEMENT SPRL	Call option	24/02/2025		20,000	0.02%	Physical
Subtotal				709,874	0.67%

Ce communiqué de presse est également disponible en français. - Dit persbericht is ook in het Nederlands beschikbaar.

Chain of control

Solvay Stock Option Management SPRL is owned by Solvay Chemicals International SA (99.99%) and by Solvay Participations Belgique SA, which are themselves owned by Solvay SA (99.99%) and Financière Solvay SA.

Solvac SA is presumed to exercise de facto control over Solvay SA on the basis of Article 5, §3, 2nd paragraph of the Belgian companies code.

FOLLOW US ON TWITTER @SOLVAYGROUP

Solvay is an advanced materials and specialty chemicals company, committed to developing chemistry that address key societal challenges. Solvay innovates and partners with customers worldwide in many diverse end markets. Its products are used in planes, cars, batteries, smart and medical devices, as well as in mineral and oil and gas extraction, enhancing efficiency and sustainability. Its lightweighting materials promote cleaner mobility, its formulations optimize the use of resources and its performance chemicals improve air and water quality. Solvay is headquartered in Brussels with around 24,500 employees in 61 countries. Net sales were €10.1 billion in 2017, with 90% from activities where Solvay ranks among the world's top 3 leaders, resulting in an EBITDA margin of 22%. Solvay SA (SOLB.BE) is listed on Euronext Brussels and Paris (Bloomberg: SOLB.BB - Reuters: SOLB.BR) and in the United States its shares (SOLVY) are traded through a level-1 ADR program.

Caroline Jacobs Kimberly Stewart Jodi Allen Geoffroy Raskin Bisser Alexandrov Media Relations Investor Relations Investor Relations Investor Relations Investor Relations +32 2 264 1530 +32 2 264 3694 +1 609 860 4608 +32 2 264 1540 +32 2 264 3687

Ce communiqué de presse est également disponible en français. - Dit persbericht is ook in het Nederlands beschikbaar.