Evaluation of hydrogen peroxide and ozone residue levels on N95 masks following chemical decontamination.

BACKGROUND: Hydrogen peroxide and ozone have been used as chemical decontamination agents for N95 masks during supply shortages. If left behind on the masks, the residues of both chemicals represent a potential health hazard by skin contact and respiratory exposure. AIM: Characterization of hydrogen peroxide and ozone residues on mask surfaces after chemical decontamination. METHODS: Various N95 masks were decontaminated using two commercial systems employing either aerosol spray or vaporization of hydrogen peroxide in the presence of ozone. Following the decontamination, the masks were aired out to eliminate moisture and potential chemical residues. The residual hydrogen peroxide and ozone were monitored in the gas phase above the mask surface, and hydrogen peroxide residue directly on mask surfaces using a colorimetric assay. FINDINGS: After decontamination, hydrogen peroxide and ozone were detectable in the gas phase in the vicinity of masks even after 5 h of aeration. Hydrogen peroxide was also detected on all studied masks, and levels up to 56 mg per mask were observed after 0.5 h of aeration. All residues gradually decreased with aeration, likely due to decomposition and vaporization. CONCLUSION: Hydrogen peroxide and ozone were present on N95 masks after decontamination. With appropriate aeration, the gaseous residue levels in the vicinity of the masks decreased to permissible levels as defined by the US Occupational Safety and Health Administration. Reliable assays to monitor these residues are necessary to ensure the safety of the mask users.

Patient education. Contraception while breastfeeding.

Practising an effective form of contraception while breastfeeding can do much to ease your mind and allow you to enjoy life more. There are many 'old wives' tales' about breastfeeding and contraception.

Clinical trials in general practice. Should I participate?

This brief paper outlines the advantages for general practitioners participating in clinical trials. In particular, it is appropriate to conduct research in general practice clinical settings rather than in hospital based trials.

Logistics of participation in clinical trials.

A decision to participate in a clinical drug trial will require a commitment in time and resources from both the doctor and other practice staff. The authors explain some of the strategies that can be used to maximise the limited time available for such research and minimise unnecessary wastage of scarce resources.

Are clinical trials in general practice ethical?

The uncertain effect on the doctor-patient relationship is often a stumbling block for many practitioners deciding whether to participate in a clinical trial. In this article, the authors explore some of the ethical issues facing doctors and patients and some of the safeguards that are in place to protect both parties as the trial proceeds.

Synthesis and characterization of mixed ruthenium/platinum mu(4)-phosphinidene, phosphorus monoxide, and related clusters.

The mixed-metal cluster complexes [Ru(4)(CO)(12)Pt(CO)PPh(3)(mu(4)-PR)] [R = N(i)Pr(2) (1), F (3)] were formed by capping the Ru(3)P face of the nido clusters [Ru(4)(CO)(13)(mu(3)-PR)] with the labile Pt(0) reagent [(eta(2)-C(2)H(4))Pt(PPh(3))(2)]. The aminophosphinidene complex 1 undergoes acid hydrolysis to yield the PO complex [Ru(4)(CO)(12)Pt(CO)PPh(3)(mu(4)-PO)][H(2)N(i)Pr(2)] (4). The fluorophosphinidene cluster 3 reacts with ethanol to form the alkoxyphosphinidene complex [Ru(4)(CO)(12)Pt(CO)PPh(3)(mu(4)-POEt)] (5). Comparison of spectroscopic and structural data for clusters 1, 3, 4, and 5 reveals the remarkable effects of the mu(4)-phosphinidene and phosphorus monoxide ligands on cluster bonding.