In its standard state arsine is a colorless, denser-than-air gas that is slightly soluble in water (2% at 20 °C)[1] and in many organic solvents as well.

[citation needed] Arsine itself is odorless,[5] but it oxidizes in air and this creates a slight garlic or fish-like scent when the compound is present above 0.5 ppm.

[14] Although this test has become obsolete in analytical chemistry, the underlying reactions further illustrate the affinity of AsH3 for "soft" metal cations.

In the Gutzeit test, AsH3 is generated by reduction of aqueous arsenic compounds, typically arsenites, with Zn in the presence of H2SO4.

[16] Reactions of arsine with the halogens (fluorine and chlorine) or some of their compounds, such as nitrogen trichloride, are extremely dangerous and can result in explosions.

For semiconductor manufacturing, this method is feasible, as processes such as ion implantation operate under high vacuum.

The gas is colorless, almost odorless, and 2.5 times denser than air, as required for a blanketing effect sought in chemical warfare.

In spite of these characteristics, arsine was never officially used as a weapon, because of its high flammability and its lower efficacy when compared to the non-flammable alternative phosgene.

On the other hand, the appearance of a black mirror deposit in the cool part of the equipment indicates the presence of antimony (the highly unstable SbH3 decomposes even at low temperatures).

The Marsh test was widely used by the end of the 19th century and the start of the 20th; nowadays more sophisticated techniques such as atomic spectroscopy, inductively coupled plasma, and x-ray fluorescence analysis are employed in the forensic field.

Though neutron activation analysis was used to detect trace levels of arsenic in the mid 20th century, it has since fallen out of use in modern forensics.

[19][20] The first signs of exposure, which can take several hours to become apparent, are headaches, vertigo, and nausea, followed by the symptoms of haemolytic anaemia (high levels of unconjugated bilirubin), haemoglobinuria and nephropathy.

There is little information on the chronic toxicity of arsine, although it is reasonable to assume that, in common with other arsenic compounds, a long-term exposure could lead to arsenicosis.

[citation needed] Arsine can cause pneumonia in two different ways either the "extensive edema of the acute stage may become diffusely infiltrated with polymorphonuclear leucocytes, and the edema may change to ringed with leucocytes, their epithelium degenerated, their walls infiltrated, and each bronchiole the center of a small focus or nodule of pneumonic consolidation", and In the second Case "the areas involved are practically always the anterior tips of the middle and upper lobes, while the posterior portions of these lobes and the whole of the lower lobes present an air-containing and emphysematous condition, sometimes with slight congestion, sometimes with none."