According to a report of the Syrian Network for Human Rights, there are evidences of chemical attacks in the city of Douma.
http://sn4hr.org/wp-content/pdf/english/Additional_Evidences_and_Investigations_Prove_that_the_Syrian_Regime_en.pdf
The Syrian National Coalition relay it to the international community, but this late remains dumb and mute on the issue.(The first photo is property of the Syrian National Coalition).
More effort is needed from the countries of the United Nations , on the ground . Yet, the United Nations published stats on chemicals in Syria, but it is without consequence in the daily reality .
Inhabitants of bombed towns have, yet, demonstrated, such as in Khan Sheikhoun , on April, 4, after being shelled by chemicals.
But there is no impact at an international level.
So, the Syrian National Coalition stresses on this report towards the United Nations and the Arab League to obtain a result.The stake is to send Assad to the ICC for crimes against humanity, and the use of prohibited weapons is a good argument.
After Sadnaya, and the discovery of gas ovens in the prison, after all the reports on enforced disappearance , the break of the Convention on Chemical Weapons is another argument , leading Assad to The Hague.
On Twitter, the hashtag #ChemicalAssad was viral a while. It is no more ; but chemicals are discovered daily in the ruins of bombed towns. 
The international community had an interest on the issue , but now that there are more and more evidences, only Syrian Rights Groups, such as the Syrian Network for Human Rights , and the interim government have an interest in it : they try to raise awareness at an international level, but it is difficult.
In fact, the International Community is focused on its own problems, wich are the returnees of ISIS, and the terrorist attacks in their territory.
So, they forgot Syria.
As the Arab League, it is focused on the Palestinian / Israeli problem, and the consequence is the same for Syria.
They have never been so many evidences of the accountability of Assad, and the interim Syrian government is alone with them.
Yet, all the proofs to send Assad to The Hague are here.
