A review of alternatives to di (2-ethylhexyl) phthalate-containing medical devices in the neonatal intensive care unit.

OBJECTIVE: To conduct an extensive literature and toxicological database review on substitute compounds and available alternative medical products to replace polyvinyl chloride (PVC) and/or di(2-ethylhexyl) phthalate (DEHP), and conduct a DEHP-medical inventory analysis at a large metropolitan neonatal intensive care unit (NICU). STUDY DESIGN: A systematic search for DEHP-free alternative products was performed using online databases. An informal audit of a large metropolitan NICU was undertaken in 2005 and 2006; 21 products were identified that could potentially contain DEHP. Availability of DEHP-free alternatives was determined through company websites and phone interviews. RESULT: Two alternative approaches are available for replacing DEHP in NICU medical products: (1) replacement by DEHP-free plasticizers; and (2) replacement of PVC entirely through the use of other polymers. Both approaches seem to provide less harmful substitutes to DEHP, but support PVC-free polymers as the preferred alternative. However, significant data gaps exist, particularly for the alternative polymers. In all, 10 out of 21 (48%) products in the NICU audit were DEHP-free; six consisted of alternative polymers and four of alternative plasticizers. Of the remaining 11 products, only three were available without DEHP at the time of the audit. CONCLUSION: Because of significant data gaps, systematic toxicological testing of DEHP-free alternatives is imperative. Continued development of alternative products is also needed.

Synthesis, characterization, thermolysis and performance evaluation of mercuric-5-nitrotetrazole (MNT).

Mercuric-5-nitrotetrazole (MNT) was synthesized on using a reported method. The product having bulk density of 1.5 g/cm3, was obtained during this work using mercuric nitrate doped with additives such as cephol/dextrin in the process. Synthesized MNT was characterized by metal content analysis, IR and ESCA. The DTA profile indicated the thermal stability of MNT up to 200 degrees C. It revealed its higher thermally sensitive [thermal sensitive figure (S) approximately 0.8] in comparison to that of service lead azide (SLA) [S approximately 0.4]. Percussion sensitivity data also showed higher sensitivity of MNT. However, it was found less friction sensitive than SLA. The chemical stability of MNT in a carbon dioxide environment was evaluated in comparison to SLA by determining mercury (gravimetrically) and lead azide (volumetrically) contents respectively. Results obtained indicated that no discernable changes occurred in MNT, even after storage for 90 days while in case of SLA, drastic change in lead azide content was observed. IR spectra of MNT sample stored in a closed aluminum dish for 5-10 years could be superimposed on that of the freshly prepared MNT sample. The performance of MNT filled detonator no. 27 assessed in terms of extent of damage on a witness plate was found equivalent to that of the standard ASA (azide, styphynate and aluminium) composition filled detonator.

Studies on lead-free initiators: synthesis, characterization and performance evaluation of transition metal complexes of carbohydrazide.

Cobalt, nickel and zinc tris(carbohydrazide) perchlorates (CoCP, NiCP and ZnCP) as well as copper bis(carbohydrazide) perchlorate (CuCP) of desired morphology and bulk density (0.85-0.95 g/cm3) have been synthesized during this work. The synthesis was carried out by addition of the aqueous solution of cobalt/nickel/copper/zinc perchlorates to the aqueous solution of carbohydrazide. The products were characterized by the metal content analysis and FTIR. The IR spectra and ESCA brought out the coordination of both the end amino groups of carbohydrazide with the central metal ion. Differential thermal analysis (DTA) curve indicated that CoCP, NiCP and ZnCP are thermally stable in the temperature range of 220-285 degrees C, unlike CuCP (120 degrees C). The activation energy determined by TG measurements was found to be 140-180 kJ/mol for CoCP, NiCP and ZnCP. Sensitivity data revealed their sensitivity to friction stimuli (1 kg). Impact sensitivity test results corresponded to h50% of 50-60 cm with the exception of CuCP (h50%, 11 cm). In order to assess the performance as detonants, the selected compounds were detonated on a lead witness plate of 3 mm thickness using fuse wire as well as evaluated in conjunction with tetryl in detonator No. 27 tube. The results obtained in terms of extent of damage to witness plate were on par with the standard detonator No. 27 containing azide, styphynate and aluminium metal (ASA) composition.

Synthesis, characterization and thermal studies of (Ni/Co) metal salts of hydrazine: potential initiatory compounds.

Nickel hydrazinium nitrate (NiHN) and cobalt hydrazinium nitrate (CoHN) were prepared by reacting their respective metal nitrates with hydrazine hydrate at 25 and 65 degrees C. The compounds were characterized by metal content and infrared (IR) spectroscopy. Differential thermal analysis (DTA) results suggest that the nickel complex is relatively more stable than the cobalt complex. The activation energy determined by DTA and ignition delay measurements corresponds to an energy of activation (E(a)) of 80+/-4 kJ/mol for NiHN and that of 150+/-8 kJ/mol for CoHN. Thermo gravimetry (TG) also revealed more rapid decomposition of NiHN than that of CoHN in the temperature region of 215-235 degrees C. High temperature Fourier transform-infrared (FT-IR) studies indicated rupture of the Ni-Co-N bond as the primary step in the thermolysis. As regards sensitivity to mechanical stimuli, NiHN was found to be less impact sensitive while CoHN exhibited less friction sensitivity. The study revealed that NiHN could be used alone as well as in combination with oxidizer/fuel as initiators depending upon the specific requirements. The effect of silver azide and glass on the sensitization of NiHN was also studied. CoHN appears to be an effective ballistic modifier in enhancing burning rates of composite propellants.