This method, developed by Lionel Milberger, is a low-cost, accessible way to detect if [hydrogen sulfide](https://publiclab.org/wiki/hydrogen-sulfide) is present in the air. The elemental copper will react with hydrogen sulfide to produce a purple-black-ish copper sulfide product, visible on the surface of the copper rod. This method has not been quantified or validated yet. Consider collaborating on this project to help assess it! 

## Design goals

As Lionel Milberger has written in [an article in TEST Magazine](https://publiclab.org/notes/warren/05-12-2017/articel-on-monitoring-hydrogen-sulfide-with-a-copper-pipe), the goals of this method are to: 

1. Be able to detect copper at health-relevant, non-fatal concentrations, from several parts per billion (ppb) up to 100 parts per million (ppm).

2. Be able to discern between copper oxides and copper sulfides forming on the surface of the copper rod. 

3. Be able to measure hydrogen sulfide even under rainy or humid conditions where a significant fraction of hydrogen sulfide will dissolve in the water.

4. Be deployable, such that it does not require a person to be present for the duration of the test (like would be necessary with a hand-held probe).

5. Be low-cost and accessible to anyone. 


## Questions

This method has not yet been quantified or validated. Mr. Milberger has observed black deposits (likely copper sulfide) forming under conditions where it is likely that hydrogen sulfide is present (near an oil field by his Texas home), and a reddish deposit (likely copper oxide) under other conditions. The lower concentration limit of this method, below which no visible copper sulfide would form, are not yet known. The rates of reaction between the copper rod and atmospheric hydrogen sulfide also are not known, nor are the influence of humidity or rain, or the relative rate of copper oxide formation. Thus, there are many questions yet to answer! More questions include: 

[questions:h2s-copper-pipe]

## Activities

Designing a field-based environmental study that uses this method would follow the general principles described in: [https://publiclab.org/wiki/general-environmental-monitoring-study-strategies](https://publiclab.org/wiki/general-environmental-monitoring-study-strategies). However, since the copper sheets will be exposed for several days in the field, the temporal resolution would, of course, only be as fine as several days, during which industrial activities and environmental conditions could change. The general principles still do apply. 

Activities people have designed using this method include: 

[activities:h2s-copper-pipe]

## Background

See background research related to this method here: 

[notes:h2s-copper-pipe-background]