The White Helmets transported drums carrying toxic materials to Saint Nicholas church, which they pretend to restore, and the National Hospital in Jisr al-Shughour (North-Western Syria).
No evidence given. Recurring pro-Kremlin disinformation on White Helmets and chemical attacks in Syria. euvsdisinfo.eu/disinformation-cases/?text=&disinfo_issue=&disinfo_keywords%5B%5D=77488&date= euvsdisinfo.eu/disinformation-cases/?text=syria&disinfo_issue=&disinfo_keywords%5B%5D=77353&date=
On 7 April 2018, a high number of civilians were killed in the besieged Syrian city of Douma, with evidence pointing towards another chemical attack by the regime, according to the EU.
According to the World Health Organisation, during the shelling of Douma on Saturday, an estimated 500 patients presented to health facilities exhibiting signs and symptoms consistent with exposure to toxic chemicals. http://www.who.int/mediacentre/news/statements/2018/chemical-attacks-syria/en/
See also Bellingcat's open source survey on the suspected chemical attack: https://www.bellingcat.com/news/mena/2018/04/11/open-source-survey-alleged-chemical-attacks-douma-7th-april-2018/
In September 2017, the UN Commission of Inquiry on the Syrian Arab Republic summarized 33 separate incidents where it had found use of chemical weapons. Since then there have been several additional suspected chemical attacks. Between March 2013 and March 2017, the Commission documented 25 incidents of chemical weapons use in the Syrian Arab Republic, of which 20 were proven to have been perpetrated by government forces and used primarily against civilians.