With all eyes on ISIS, concerns about Syria’s chemical weapons program have faded from public view. But recent confirmation of the use of chlorine gas in Syria and the discovery of undeclared weapons production and research facilities there demonstrates that the international community’s work to eliminate Syria’s chemical weapons is far from over.

When Syria joined the Chemical Weapons Convention (CWC) last year in a Russia-brokered deal to avoid U.S. military strikes, the immediate concern was how to get the most dangerous elements of Syria’s chemical weapons stash out of the country and where to destroy them. Because the ongoing civil war in Syria ruled out the normal procedure of building a destruction facility near the stockpiles, most of these chemicals were shipped out to other locations. The “worst of the worst” were destroyed on a specially equipped U.S. vessel, the Cape Ray, while many others were transferred to facilities in Europe. Despite some delays, the supervising international body, the Organization for the Prohibition of Chemical Weapons (OPCW), reported that 94% of these chemicals had been destroyed by Aug. 2014. According to press reports, the dismantling of previously declared facilities for researching or making chemical weapons is expected to begin this month.

Nevertheless, Syria retains plenty of poisonous industrial chemicals that can be used as weapons. Chlorine, for example, which was widely used in World War I and has been confirmed to have been used in Syria, is ubiquitous in daily life and industrial processes (it is among the ten highest-volume chemicals manufactured in the United States).

Although chlorine is not explicitly covered by the convention’s regime for dual-use chemicals (i.e., those that have both industrial and offensive uses), it can still be considered a chemical weapon. Under the so-called “general purpose criterion” of the treaty, “chemical weapons” are broadly defined as:

 Toxic chemicals and their precursors, except where intended for purposes not prohibited under this Convention, as long as the types and quantities are consistent with such purposes

Purposes permitted by the convention are limited to:

(a) Industrial, agricultural, research, medical, pharmaceutical or other peaceful purposes;

(b) Protective purposes, namely those purposes directly related to protection against toxic chemicals and to protection against chemical weapons;

(c) Military purposes not connected with the use of chemical weapons and not dependent on the use of the toxic properties of chemicals as a method of warfare;

(d) Law enforcement including domestic riot control purposes.

In other words, any use of a toxic chemical for a purpose not listed – e.g., as a method of warfare – would constitute a use of chemical weapons in violation of the treaty. The maintenance of stocks not consistent with industrial use would also contravene the treaty.

A recent OPCW fact-finding mission confirmed that chlorine was used in attacks on three villages in northern Syria. As in the investigation of last year’s chemical weapons attacks in Syria, OPCW did not tell us who used the weapons. And again, the U.S. and its allies have accused the Assad regime, while Russia blames “extremists.”

The U.S. and other Western nations have protested these attacks, but they need to do more, both to demonstrate to the world that they haven’t gone soft on Assad and to uphold the norm against chemical weapons use. Under the Chemical Weapons Convention, any country can request the OPCW to conduct a formal investigation into the use of chemical weapons in Syria. This would be different than the recent fact-finding mission in important ways. It would be backed by the political weight of the country requesting it and, based on the inspection team’s findings, the OPCW and the international community would have to squarely address the issue of Syria’s compliance with the convention and take remedial steps.

Remedies available under the convention include: suspending a country from the treaty regime, recommending collective measures, and bringing the issue to the U.N. General Assembly or Security Council. The latter’s decision on the Syrian program stated that the Council “Decides, in the event of non-compliance with this resolution, including unauthorized transfer of chemical weapons, or any use of chemical weapons by anyone in the Syrian Arab Republic, to impose measures under Chapter VII of the United Nations Charter.” Readers will recall that there was concern that this part of the resolution didn’t provide for automatic penalties on Syria.

It is widely assumed that Russia would block any attempt by the Council to penalize Syria. But this would be measurably harder if the OPCW found a violation of the treaty. Like the inspection itself, the imposition of sanctions under the Chemical Weapons Convention would put pressure on Assad to live up to his promises.

But it is not enough to deal only with the issue of chlorine use. The international community needs to develop a broader approach for handling Syria’s industrial chemicals.

The Chemical Weapons Convention requires countries to declare specified dual-use chemicals and related facilities, which are subject to a regime of transfer controls and inspections, the rigor and frequency of which depend on the toxicity of the chemical, its utility in warfare, and the extent of its commercial usage.

Syria is known to have a well-developed chemical industry, but it is unknown how many chemical factories the Assad government has declared, and almost nothing has been said by either the U.N. Security Council or the OPCW about how they intend to deal with Syria’s dual-use chemicals. No doubt this has much to do with the focus on the immediate threat posed by stocks of mustard and sarin. And obviously, the security situation in the country poses huge challenges to the regular industrial inspection regime envisioned by the treaty. But ignoring toxic industrial chemicals leaves a gaping hole in the effort to remove chemical weapons from this volatile region. Creative solutions, of the type developed for the Syrian weapons stockpile, must be found for dual-use chemicals as well.