Derivatives of 3（5）,4-Dinitropyrazole as Potential Energetic Plasticisers

The development of a pseudo-one pot synthesis of 3（5）,4-dinitropyrazole enabled us to use it as a starting material for energetic plasticisers. Its acidic proton allowed simple derivatisation on one of the ring nitrogens. The thermal characteristics of two derivatives were evaluated. For instance, the N-allyl compound was a liquid with very low glass transition temperature, whereas the N-propargyl compound was a sticky solid at ambient temperature. The two compounds were both thermally stable according to STANAG 4582.

Initial assessment of imports of chlorinated paraffins into Nigeria and the need of improvement of the Stockholm and Rotterdam Conventions

Short-chain and medium-chain chlorinated paraffins(SCCPs/MCCPs)are of concern due to their persistence,bioaccumulation,and toxicity.SCCPs were listed in 2017 as persistent organic pollutants(POPs)in the Stockholm Convention and Rotterdam Convention for Prior Informed Consent(PIC)procedure.MCCPs are evaluated in the POPs Reviewing Committee for listing.Studies in Africa demonstrate high SCCP/MCCP levels in house dust and human milk.Therefore,this study undertook an initial assessment of the production and import situation in Nigeria.The Nigerian government has not assessed SCCPs yet and has no registered exemptions for SCCPs and therefore should not produce or use SCCPs.Also,Nigeria has not notified Rotterdam Convention of PIC procedure and,therefore,no SCCP should be imported into Nigeria.Since no local production of SCCPs/MCCPs was observed in Nigeria,this study therefore compiled data on importation of SCCPs/MCCPs and products which may likely contain these chemicals from the UN Comtrade Database for the period 1996 to 2018.Despite the listing of SCCPs in the Rotterdam Convention,there is still no specific Harmonized System(HS)codes for SCCPs/MCCPs.This study therefore used HS codes of product categories known to contain SCCPs/MCCPs.HS substance categories under which SCCP/MCCPs are usually imported include plasticisers and other product categories that amounted to 229,779 and 518,342 tonnes respectively but without specific information on the type of plasticiser.About 39%of PVC and rubber imports of 2,683,015 tonnes and 3,516,052 tonnes respectively contain plasticisers.Based on the SCCP and MCCP impact factors from literature for China,the highest amount of SCCP(33,712 tonnes)was imported in the different PVC products while rubber products accounted to 1386 tonnes and PUR foam to 2331 tonnes.The amount of imported MCCPs in PVC products(25,599 tonnes)and rubber products(32,317 tonnes)was in the same order of magnitude while MCCP imported in PUR foam was estimated to 2020 tonnes.At the end of life(EoL),these product categories most likely contain appreciable amount of SCCPs possibly above Basel Convention low POP limit.This will hamper recycling and circular economy for these waste categories and generate POPs stockpiles/wastes that are difficult to manage/destroy in Africa.Hence there is an urgent need for specific HS Codes for SCCPs and industrial POPs currently produced/used for better control.Presently,products containing SCCPs are not labelled and are imported in huge quantities into Nigeria,without monitoring.In its current form this rather conveys a pseudo-safety for industrial POPs that do not exist.The Rotterdam Convention needs to establish specific HS codes for POPs for an appropriate PIC procedure and effective control of industrial POPs still produced.Furthermore,products containing SCCPs(and other POPs)require labelling and should also be covered under the Rotterdam Convention.The study highlights that Nigeria should urgently update the NIP for chemicals listed from 2015 to 2019 with a detailed SCCP inventory and develop monitoring capacity for market surveys.The Rotterdam Convention does not function fully and need to significantly improve to assure PIC procedure.