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Parrots & Heavy Metal (the substance - not the music)

Metal is an awesome material that has been exploited by humanity for millennia to produce tools, build things, decorate our living spaces, get us to the depths of the oceans and even into space. But it is not risk-free. All metals have the potential to be toxic to living things; it’s just a matter of quantity and the method of delivery. Whilst most of the safety precautions in place to prevent metal poisoning in the human population is quite effective, we don’t tend to chew on and/or swallow metal things in our environment. Parrots do!

It is not always easy to tell what metal you have just by looking at it, but there are ways to help you figure it out.

  1. Knowledge
  2. A Magnet
  3. Samples
  4. Hydrochloric Acid and/or Copper Sulphate Solution – for the thorough investigators

In this article I will briefly cover what heavy metal poising is and then cover in length the different metals you might come across and ways to identify unknown metal substances.

Heavy Metal Poisoning

In the context of health the term "heavy metal" is used as a description for a metal or metal compound with the potential to cause human or environmental toxicosis (poisoning). For parrots the most talked about form of heavy metal poisoning is zinc toxicosis.

Whilst products containing zinc are relatively harmless to humans it is more down to the fact that we don’t spend our day chewing on them; zinc is not considered safe for use in products that will come into direct contact with our food and drink.

Zinc is an element that is essential to most living things in trace amounts. For adult humans acute zinc poisoning can result from a single dose ranging from 225 to 450 mg, regular smaller doses of 50 to 150 mg per day may cause chronic poisoning. For birds, who weigh far less than a human and have a much higher metabolic rate, the dosage for poisoning is much smaller.

Vets are now able to measure serum zinc levels in avian patients (though special care must be taken to avoid contamination of the sample from other sources). Currently normal levels are thought to range from 0.9-2.5ppm. In cases where birds that have shown signs of toxicity and have had their blood tested they have had serum zincs ranging from 2.5-19ppm.

In one study performed by an avian veterinarian in California, 43 cockatoos suspected to have zinc toxicosis were tested and 37 found to have high levels of zinc. 34 of these cockatoos were feather picking and all but one ceased after receiving treatment and the suspected sources of zinc were removed from their environment.

As with most medical issues there will always be mitigating factors to zinc-poisoning. Its not all about how much zinc is present in their environment; factors like their individual personality, their species or even just their beak strength will have an affect on the quantity of zinc they may ingest. Their genetics, general health and other nutritional input will likely affect their tolerance for zinc as well.

What does zinc poisoning look like?

The signs of zinc toxicosis are often non-specific and can be misdiagnosed as something else without a thorough history and serum testing. There may be vomiting, loss of appetite, dark green diarrhoea, increased water consumption and urination. Certainly general signs of being unwell & miserable are usually noticed by the owner. Many birds will feather pick with elevated zinc levels, and in severe cases, the bird may develop seizures or die.

Key Metal Processes Explained


An alloy is a material that has metallic properties and is composed of two or more chemical elements of which at least one is a metal. For example steel is mainly iron with a little bit of carbon; stainless steel is iron with the addition of carbon, chromium and sometimes nickel. Alloys will have different properties even with just a small adjustment to the ratios of each of their usual ingredients.


Welding is the joining of metal parts by heating it to such a high temperature that it essentially melts together.


Soldering is using an alloy of low melting point to join other metal parts together. The most common solders are alloys containing tin, lead, zinc, antimony, bismuth, indium, gold, silver, cadmium and copper. Lead-free solders are becoming more widely used these days but making reliable joins with them is more difficult.


Die casting is forcing molten metal under high pressure into reusable molds. It is an efficient, economical process that can produce thousands of identical pieces (simple or complex in design) with smooth or textured surfaces that can easily be plated or machined afterwards if necessary.


Electroplating is a process in which a thin layer of a metal is deposited on something via electrolysis. It is done to beautify, enhance or protect the underlying material, which is typically some kind of metal or metal alloy (most frequently steel). Normally the electroplated layer is too thin to affect the magnetic quality of the base metal.


It used to be that if the metal was artificially coloured you could assume it was aluminium. This is no longer the case. In the past decade coloured lacquers have dramatically improved in look and performance due to a process called electro-coating, electrophoretic lacquer coating or e-coating. The consequence is you could easily mistake anything from zinc die casting, copper, brass, galvanized steel, stainless steel or even plastic or wood for anodised aluminium. This is particularly relevant for parrot toys because small decorative parts like bells are much cheaper to make with a zinc die cast and a colourful e-coat than anodised aluminium.

Powder Coating

Powder coating is usually electrostatically applying a polyester or epoxy powder to an object, usually cold rolled steel, which is then heated to fuse into a durable and protective layer. The quality of powder coated cages can be fantastic or terrible – some powder coats will stand up to decades of battering from a beak, but others can start to peel and chip very easily.

A potential hazard in powder coated cages is that zinc hardeners are sometimes incorporated into the powder coating formula and high zinc content primers may also be applied to the steel before the powder coating. For a while cages were being tested and many were being found to have dangerous levels of zinc (or lead). The good news is that cage companies have been responding and in many cases these problems have been remedied. Nevertheless it would be wise to look into the matter if you have any concerns.

If your bird has been diagnosed with heavy metal poisoning it would be worth looking into getting your cage tested by scraping off a sample and sending it to a lab. Contact a testing lab for quotes and more information of how to collect the sample.

Corrosion & Rust

rustychain.jpgMost corrosion you will see in hardware is the metal reacting with oxygen to produce oxide(s) and/or salt(s) of the original metal.

Water aids the process by combining with other available elements (such as carbon dioxide) to form a weak acid. A little bit of the metal dissolves into this conductive solution and makes the process of oxidation much easier and faster.

Oxidation of metals can occur in fresh water, seawater, salt solutions and alkaline or basic media but ONLY if dissolved oxygen is also present. This means a damp environment is often much worse for metals than being totally submerged in water because in fresh air there is LOTS more free oxygen to oxidise with.

Although oxidation is sometimes called rusting technically it is not the same. Rust is specifically iron oxide which is seen in corroding pieces of iron or steel (an alloy mainly composed of iron). It is orange in colour and it is pervasive; when steel begins to rust it will continue to rust all the way through until it completely disintegrates. Most other metals only oxidise for a short time and only on the surface. In many cases this oxidation is actually desirable because it forms a protective layer.

The danger of the oxide depends entirely on what metal it is an oxide of, but because it is much easier for a bird to consume large quantities (deliberately or accidentally) it would be wise to remove any corroding metal from your bird’s environment.

ALL metal (and their oxides and salts) should be considered toxic in large amounts.

Key Metal Types Explained


Steel is an alloy that consists mostly of iron with a carbon content between 0.2% and 2.1% by weight, depending on the grade. Most of the metal your parrot will encounter will be steel in one form or another. Wrought iron and cast iron are just different classes of steel. ‘Alloy Steel’ is a class of steel that is particularly strong – it is usually heat treated and left un-plated giving it a dull black finish. Another steel, often found in nails, is ‘Bright Steel’ which some may accidentally assume to mean ‘Nickel Bright’. Bright Steel is not coated with anything, whereas Nickel Bright is nickel plated steel.

Steel, because it is mainly composed of iron, is magnetic.

By itself steel is non-toxic to parrots, however most steel you will encounter will have various surface treatments such as a silver or yellow zinc plating, galvanization, nickel or chrome plating etc. These treatments CAN be toxic.

Stainless Steel

Stainless steel is an alloy of high carbon steel (about 2% carbon) and chromium (mainly) and comes in many grades depending on its final use. It is highly resistant to corrosion and because the anti-corrosive properties are inherent to the metal (rather than a layer on top) it will not lose this resistance if scratched during installation or use. Any rust that does appear is mainly an aesthetic issue. Unlike regular steels, which can completely rust away, the stainless parts which show rust are usually only affected on the surface. It'll look bad, but should stay structurally sound.

For parrots the most important quality about stainless steel is that it is non-toxic.

The common wisdom these days is that stainless steel is not magnetic, and thus easily tested for. However life is never that simple. Stainless steel can be broken down into two main types:

300 Series - Austenitic

Stainless steel in the 300 series (of which the most common ones you will encounter are 304, 316 & 18/8) are austenitic which means they’re non-magnetic. The 300 series has a high chromium and nickel content making it the most corrosion resistant of the stainless group. The 300 series is predominantly found in stainless steel hardware, and will likely be the stainless steel used by small toy manufacturers (like us here at My Parrot Shop), who source their stainless steel from suppliers to the marine industry. There is a 200 series that is austenitic (and safe) also, but in the context of parrots you don’t come across it very often.

400 Series - Martensitic and Ferritic

Another type of stainless steel you will be encountering more and more in parrot toys (now that some of the big producers are finally starting to respond to the demand for safe metal components) is Martensitic and Ferritic stainless steel, otherwise grouped together as the 400 series. The 400 series is not as corrosion-resistant as the 300 series but they are easier to put through a machine to make shapes such as bells and usually, perhaps more relevantly, are much less expensive.The important thing to note about this is that the 400 series will be magnetic (though to a lesser extent than plain steel).

Typically the stainless steel you will see will have a blackish silver tone and a dull but reflective shine to it. However this is only true if the stainless steel has been polished! Unpolished stainless steel will actually have a matt black appearance similar to alloy steel. Polishing stainless steel is fiddly and expensive so sometimes when a lovely shiny surface is wanted the stainless steel will be electroplated with nickel or chrome instead. (Zinc would be a very unusual plating choice in this instance because it doesn’t usually make for a very attractive finish.)

Stainless steel, especially the 300 series, is very expensive compared to other hardware options and will sometimes have a stamp indicating what type of stainless steel it is.

Chrome, Hexavalent Chromium & Chromates

chromewheel.jpgAny metal labelled as chrome is a chromium plated object because nothing is ever made using solid chrome. Usually the underlying material is steel, but occasionally you might find it on an object (usually one that is die cast) made of aluminum, brass, copper, stainless steel, zinc or even plastic. Chrome, by itself, is not magnetic.

Decorative chrome or nickel-chrome plating is what non-engineering folk come into contact with regularly. It is performed after one or two layers of nickel plating, and, on occasion there might be a layer of copper before that.

Chrome plating is brighter, bluer (less pale, grayish, or yellowish), and more like a mirror than other finishes. It’s unlikely you’ll find chrome plating on many parrot toys, with the exception of chain, but you are very likely to have a range of chrome plated items throughout your home and car.

Chrome-plating, water insoluble chromium (III) compounds and chromium metal is essentially considered non-toxic to humans and birds but other forms of chromium can be carcinogenic.

Chromium in its hexavalent form (Chrome VI or Hex Chrome) is a proven carcinogenic and is regulated under numerous pieces of legislation in Europe, China, Australia and pretty much everywhere else. The European RoHS Directive, since 2006, has prohibited the use of ‘hex-chrome’ or ‘hex-chromates’ (not to mention lead, mercury & cadmium) in consumer products, including electronics, appliances, sports equipment and toys, and as a consequence hexavalent-free chrome is now in reasonably common use all over the world. However hexavalent chromium is still used (for a variety of reasons) and not just in chromium plating.

Many fasteners will have a chromate conversion coating on top of their regular plating to further protect against corrosion; this is particularly true for zinc-plated fasteners.

Zinc plating will often have a shiny silver-blue or golden-orange appearance referred to as clear/blue/silver passivated or yellow/gold passivated respectively, or sometimes just with the name blue zinc or yellow zinc (frankly it can get quite confusing). These passivating layers can be made from a wide range of chromates, with various tones and one of the possibilities is hex-chromate .

Whilst it is becoming more and more unlikely a zinc-plated part will have this carcinogenic coating this is no-where near a guarantee that the zinc parts in your parrot toys were passivated using a hex-free chromate.

Zinc or zinc coated steel

zinclump.jpgZinc, if ingested it has been shown to cause acute or chronic illness and even death in birds.

Zinc is the most reactive of metals in common use and is very susceptible to ordinary liquids such as water, soft drinks and vinegar. Because it’s cheap and highly reactive it is frequently used to protect steel from corrosion. Most metals used for plating steel simply act as a protective barrier, but zinc protects steel by sacrificing itself to the corrosion process. The thicker the layer of zinc the more protection it offers.

There is a difference between zinc-plated and galvanised steel but many people use the phrases interchangeably; which is important to be aware of when making enquiries.

All true galvanizing is hot dip galvanizing - where the parts are submerged in molten liquid zinc, creating a very thick layer on top of the steel that will be extremely dull and rough in appearance. Galvanized fasteners are frequently used in harsh coastal environments because of their superior corrosion resistance. As a parrot the most likely contact with galvanised products will be via their aviary wire or galvanised fasteners or even galvanised feeding bowls. Also the budget (and unfortunately a good portion of the not so budget) parrot toys that are based on wire will be based on galvanised wire. This is a pity, because as far as stainless steel prices go, stainless steel wire is very affordable (though admittedly difficult to work with).

Much of the zinc-coated hardware you will come across in parrot toys will have been electroplated rather than dipped. When the steel has been electroplated it is somewhat safer, because there is far less zinc (typically the layer is only 3 microns thick) and it has been bound to the steel. The zinc, however, can still contaminate water or soft foods with prolonged contact.

Because coating steel in zinc is one of most effective and cheapest way to prevent steel from rusting (and for the most part can be considered non-toxic to humans) it is wise to assume the hardware on the parrot toy is zinc-plated unless the manufacturer has specifically stated which alternative metal was used. DO NOT automatically trust labels such as ‘Bird Safe’ or ‘Non-toxic’.

Zinc plated steel is corrosion resistant but will rust if the coating is damaged or if exposed to a harsh environment.

A Special Section all about White Rust

p1080168.jpgMixed messages about white rust, sometimes called wet storage stain or white storage stain, abound with some people saying its good and others saying its bad, and it’s not just parrot owners that are confused. The confusion stems partly from definition and partly from the zinc corrosion process being quite complex. So put on your chemistry goggles and read on:

The full benefit of using zinc on steel does not come into play immediately upon galvanising or electroplating. The zinc actually needs to go through several chemical processes first. This process takes time, which is why people will often recommend you ‘weather’ galvanised steel for anywhere up to 12 months before use.





1)      First it needs to go through an oxidation phase where the zinc will react with oxygen from the air to produce zinc-oxide.

Zn + ½O2 → ZnO

2)      The next step is a hydration phase where zinc-oxide and water react to produce zinc hydroxide.

ZnO + H2O → Zn(OH)2

3)      Finally, the zinc-hydroxide will react with carbon dioxide from the air to form zinc carbonate (and water).

Zn(OH)2 + CO2 → ZnCO3 + H2O


Over time, and under the influence of cyclic weathering (ie wet, then dry, then wet, then dry etc), a nice continuous, compact, stable (insoluble in water) and durable film of zinc carbonate will coat the galvanised (or zinc-plated) steel giving it a dull-grey appearance.

white-rust-corrosion.jpgWhen the surface is further exposed to rain or condensation, this protective film will act as a barrier between the moisture and the zinc underneath. This type of chemical layer is called a passive film. It is the presence of this passive film that slows down the reactivity of the zinc, thereby dramatically reducing the corrosion rate of the zinc coating – typically to 2 microns or less in thickness per year in normal environments.

White rust occurs when the normal oxidation process of the zinc surface gets stuck in the hydration phase. The hydration phase rapidly consumes the zinc, at a rate 20 – 50 times higher than normal, producing lots & lots of zinc-hydroxide (with zinc-oxide mixed in) which generally presents as a powdery, flocculent (fluffy) or waxy white residue, sometimes with black patches (which is to do with the steel underneath).

ALL the different oxides of zinc are just as toxic as the zinc itself to a parrot; however a zinc-carbonate layer is quite durable thus the risk of a parrot ingesting it in dangerous quantities is reduced. But one always needs to take into consideration the species and individuals kept within the aviary. Some birds will do little else but land and occasionally climb about on the wire, whilst others will treat it as a chewing challenge and regularly chow down on it. Galvanised wire in parrot toys can pose a greater risk due to the fact it will likely face more chewing and licking and face a harsher environment because of coming into regular contact with water, acidic food and faeces.

What to do when your options are limited

So if you are using galvanised steel there are some things you can do to reduce its danger. The goal is to get past the white rust stage into the zinc-carbonate stage. The best way to encourage zinc-carbonate to form is to 'cure' it outdoors for a minimum of 2 months before introducing your birds to it. The longer it is weathered the thicker and better formed the zinc-carbonate layer will be.

Now the passivating zinc-carbonate layer will only be as good as the surface it forms on. If you wire has lots of tags, bumps and pits the more difficult it is for the zinc-carbonate layer to form smoothly and uniformly, and the more likely there will be weak areas that will lead to deposits of white rust or the steel beneath rusting – not only will this reduce the life of the wire, it will make it much easier for your parrots to chew pieces off zinc. So:

1)      Inspect before purchasing – look for a smooth and well-applied galvanise, run your hands over it to feel how smooth it is (watch out for metal splinters) and check for signs of white rust - a sign that the product has been badly stored at some point.

2)      When storing keep it dry and make sure water is able to drain off it if necessary and good air circulation is permitted between the surfaces.

3)      Use cutting implements , a wire brush and sand paper to remove tags and lumps of zinc and any corrosion you can see before beginning the weathering process.

4)      White vinegar is a very effective and environmentally benign treatment for white rust. Apply with a dishwashing brush (or wire brush if its severe) and rinse residues off with clean water. Also most wire is coated with an oil to help protect it during storage; likely to be toxic - giving it a good scrub with vinegar should help remove this as well.

5)      Keep it clean! Zinc is very reactive - the more acid it encounters the more corrosion there will be, and parrots like to deposit acidic fruit and faeces everywhere.

6)      Inspect for white rust and damage regularly.

7)      Oxidisation is a continuous process that slows down (but never stops) as the carbonate layer gets thicker & thicker over time. An occasional round of cleaning with vinegar will help keep this process as free of white rust as possible (don’t forget to rinse with water).

A light white rust will show as a faint film of white powdery residue. This is seen frequently in newly galvanised products - it can be brushed or washed off, or if you are in the process of weathering it, the cyclic weather will usually sort it out. However, do understand that if you can see it - there is too much of it and it will inhibit the formation of the preferable carbonate based oxides.

Nickel Plated Steel

nickellump.jpgNickel plated steel is more expensive than zinc plated steel but much cheaper than stainless steel. It is non-toxic for birds.

Nickel plating generally adds a yellowish tint to the metal and usually provides a more reflective and shiny finish compared to zinc plating. Nickel plating works well on hardware items; however because of the expense it is normally reserved for decorative applications. Approximately 10% of the human population has an allergy to nickel which over the past decade (as awareness has grown) has led to a further reduction in its availability to the parrot toy cottage industry who are often limited to purchasing components ‘off the shelf’ and can only do so if they’re on the shelf to begin with.

Both nickel and the underlying steel are magnetic. Nickel fares well in dry conditions but if contact with water or acidic substances (like fruit!) is not kept brief, it quickly deteriorates and the steel beneath will start to rust immediately.



aluminiumlump.jpgAluminium has a low density and weighs about a 3rd of other metals. Aluminum can be made stronger and more durable through a process called 'anodizing' which thickens the natural passive oxide layer on its surface. During or after this process aluminium is frequently coloured with organic dyes. Most of these dyes are compliant with the European Restriction of Hazardous Substances Directive (RoHS), or similar legislation found throughout the world.

Aluminium is not magnetic and can for the most part be considered non-toxic for birds.

There have been a couple of reports about pet parrots being affected by heated aluminium foil when the owner was cooking - however these have been attributed to fumes from its non-stick polymer additives rather than the aluminium itself. However there have been several studies showing detrimental effects of elevated levels of aluminium (whether naturally occurring or not) in the habitat of wild birds. Nevertheless it is worth restricting your parrot’s access to things such as aluminium foil as it quite easy to chew and consume (which is not the case for solid anodised aluminium objects which are actually pretty tough), and


copperlump.jpgOrange in colour, soft and non-magnetic, copper is some-what toxic to birds. The most likely way your parrot is going to come across copper is chewing on electrical wire or a decorative household object. If you have any copper that shows signs of oxidation (green powdery patches) it should be removed immediately as copper oxide is much more toxic. Many copper products will be given a thin tin coating to protect us humans from copper poisoning. If the tin oxidises it is non-toxic.





Tin is non-toxic and is mostly used these days in solders or in electroplating steel in things like ‘tin cans’ because it is food safe. However there can be some confusion over tin as it is also the colloquial phrase used for sheet metal. Your ‘tin’ roof, or ‘galvanised tin’ watering can, or ‘rusted tin’ decorative craft piece will be galvanised steel with a misleading name.


leadlump.jpgLead is normally a dull looking metal with a dark blue-grey colour and is very heavy compared to other metals. It is extremely toxic to us and birds! Common sources of lead in the home include paint (whilst lead is legally required to be included at ‘non-toxic’ levels in regular household products these days, these levels are based on humans, who don’t take chunks out of the wall and chew it!), curtain weights, older stained glass window frames and tiffany lamps, pewter antiques, lead batteries and weighted ashtrays and toys. Many of the items (such as champagne foil) that used to contain lead no longer do- now that we are aware of its toxicity, but products like children’s toys can contain lead weights so long as a child cannot easily get at the lead. Keep this in mind because many things that are inaccessible to a child are easily accessed by a parrot. Upon the introduction of regulations such as the European RoHS Directive lead-free solders are becoming more widely used for items that young children may come into contact with (since young children are likely to place things into their mouths), or for outdoor use where rain and other precipitation may wash the lead into the groundwater, but most lead-free solders are difficult for creating reliable joins so it is not always the first choice. If your parrot chews at a soldered join it is wise to investigate what the solder might be made from or restrict access to it.

Another material to be concerned about when it comes to lead is soft plastics like PVC and rubber. Lead is a good substance for producing their soft and malleable nature and has been found at high concentrations in some pet toys. Lead has also been found in some glazes (especially red) on ceramic food & water bowls for pets. Lead in these products has been shown to leach into food and water. Some tennis balls intended for pets (but not ones intended for humans) have also been shown to contain high concentrations of lead. To relieve some of your worries the very popular JW Insight bird toys Nut Case, Bird Bopper & Chompion are lead free.

Pencil lead, by the way, is made from graphite (carbon). Whilst it can generally be considered non-toxic, letting your bird eat the inside of a whole pencil may cause gastrointestinal irritation.


brassfitting.jpgBrass is an alloy of copper and zinc, where the zinc content will range from 15 – 50%. Lead (typically at around 2%) is sometimes added to increase machinability. With high levels of zinc, let alone the possible source of lead, it is not surprising that brass has been shown to be toxic. However cases of brass poisoning have not been reported often and mainly in the larger parrots (probably because they’re more capable of chewing pieces off). Brass has a bright yellow look to it. You will find brass as a solid metal (non-magnetic) or as a plating over steel (magnetic) for various hardware applications. Brass is used decoratively on household fittings and fixtures and in musical instruments. The most likely place a companion parrot will come across it is in bells that frequent many small bird toys, and padlocks on a cage or aviary door.




bronze.jpgBronze is an alloy of copper and tin, of which typically tin will make up about 12%. It normally has a rich golden tone ranging towards a darkish red-brown tone. Bronze is only really found in the occasional decorative household item or fitting and fixtures. It probably isn’t hugely toxic, but there is not much evidence either way probably due to parrots not being frequently exposed to it.





Cadmium containing products have started entering the market place more now since international laws about lead content were put in place, as Cadmium, like lead, is a cheap and very effective ingredient for many applications. It is extremely toxic to humans and birds if ingested. Small cheap fashion jewellery charms, bracelets and necklaces you might find in a $2 shop, gumball machine or K-Mart can sometimes have a high cadmium content, as well as rhinestones and similar sparkly beads on collars for cats and dogs It’s generally thought to be ok for skin contact, just not so good if you chew, suck or swallow it. Cadmium (often together with lead) has been found in a host of products regardless of brand, price or country of manufacture.

Identifying an Unknown Metal

1st Level: Narrowing the field of possibilities with knowledge

It is often easy to rule out a bunch of metals that your item could be made from just by having an understanding that all metals and their alloys have different properties that make them suitable for specific purposes. Hopefully the contents of this article will have provided much of this knowledge for you but there is always a wealth of good information to be found online if you’re good at web-browsing. Don’t forget that it never hurts to ask someone in the metal finishing or hardware trade – I do this sort of cold-calling information gathering regularly and everyone has always been more than willing to help explain things to me.

2nd Level : Test with a magnet

Only iron, cobolt, nickel and their alloys are magnetic. Having a quality magnet is an excellent way to narrow the field of possibilities. You can purchase a good magnet cheaply at a hardware store. Promotional fridge magnets are not strong enough to be good testers but other decorative fridge magnets might do the job.

3rd Level: Compare against known samples

assorted3.jpgVarious metals will differ in colour and brightness; however these differences are often subtle. It is much easier to tell if something has a bluish tint or a yellowish tint or is light in weight or heavy when comparing it side by side with something else. Likewise because some alloys are more magnetic than others, putting your magnet against a confirmed strongly magnetic item first can help you gauge just how magnetic the unknown metal is.

Most people will have a decent sampling of the various metal and metal-plated fasteners in their tool box already but a quick trip to the loose-parts section in your hardware store will fill any gaps in your collection without costing more than the hotdog you purchase on the way out. Gather a few items for each confirmed material and store them in separate labelled plastic zip-lock bags (which is easier than trying to put stickers or tags on the items themselves). When making your comparisons it is best to do so in natural light.





4th Level: Testing with chemicals

Sound dangerous? It can be. If you choose to perform tests with either of the following chemicals please wear protective clothing, including rubber gloves (latex if you have them is better for manual dexterity) and fully-enclosing safety goggles. Perform your experiment outdoors, over a safe material like glass or crockery, don’t breath in the fumes and absolutely keep children and pets away!

Hydrochloric Acid - Sometimes called muriatic acid, a dilute (but still very effective!) hydrochloric acid can usually be found at hardware stores or paint shops, but it is worth making a phone call to check before getting in the car.

Copper Sulphate Solution - Copper sulphate crystals, sometimes called "Blue stone" can usually be purchased from horse, hardware or garden supply stores. You will need to dissolve about 8 grams of copper sulphate in about 500 ml of water.


Clean (swishing about in soapy water should be fine) and dry your parts before testing to avoid skewing your results with contaminants. You should also use fresh equipment (or clean the equipment) for each test, not just to avoid skewing your results but because one should always be careful mixing chemicals when you don’t know what the results might be!

Either swab the hydrochloric acid or copper sulphate solution onto the part with a cotton bud, or put some droplets on the item with a plastic or glass eye dropper or simply put the part into a small glass of the liquid (using a fresh batch for each test).

Have a bucket or bowl filled with cold water available to wash the part when you’re finished (also good if you have an accident). Be sure to rinse and dry off any metal parts that pass the test – otherwise you might come back half an hour later to learn that stainless steel or nickel does corrode eventually!

Dispose of left over test fluids by diluting with plenty of water and pouring down the sink.

The Reactions

reactivity-scale.jpgNow, if you can think back to your school days you might remember learning about the Reactivity Series. The Reactivity Series is simply a list of metals in order of declining relative reactivity; i.e. the top metals are more reactive than the metals on the bottom.

Although hydrogen and carbon aren’t metals they are included in the reactivity series as key reference points.

The two things to understand when doing your experiments are:

  • A metal will displace (take the place of) a less reactive metal in the reactivity series.
  • The greater the interval between the two metals the more vigorous the reaction.

For our two experiments in particular this means:

Hydrochloric (HCl) Acid Reactions

Copper Sulphate (CuSO4) Reactions


For all elements above hydrogen in the Reactivity Series:

Hydrogen gas will be released and the metal will become part of the solution. The further from Hydrogen the test metal is the more fizzy and bubbly the reaction will be.


For all elements above copper in the Reactivity Series:

Copper will deposit onto the surface of the other metal and the intensity of blue in the remaining solution will decrease or disappear. The further from to copper the the test metal is the faster it will happen.

 So what might you see specifically?

Here's a sampling from tests I did with HCl:

Stainless Steel after several minutes Zinc Plated after 30 seconds Nickel Plating after 1 minutes Gold Passivated Zinc Plating after 30 seconds Aluminium after 3 minutes
ssafterseveralminsinhcl.jpg zincandhclafter30seconds.jpg nickelafterapprox1minhcl.jpg goldpassivatedzincandhcl.jpg aluminiumafter3mins.jpg



Hydrochloric acid will attack zinc immediately, there will be obvious fizzing and bubbling and the object will turn black where it has been exposed. If your zinc coating is pretty fresh there may still be a microscopic layer of chromate or special oil on it (something the manufacturers will do to initially protect it from corrosion whilst it is building its own passive film of zinc carbonate). This layer wears off pretty quickly in normal environs, but does have the potential to delay the reaction with hydrochloric acid.


Whilst more reactive than Zinc, the reaction will be delayed due to the unreactive aluminium oxide layer needing to dissolve first in either the hydrochloric acid and copper sulphate solution. After a minute or two it should start to fizz and bubble fairly dramatically in the hydrochloric acid and in the case of the copper sulphate solution it will eventually gain layer of copper whilst the solution gradually loses its colour.
If you are trying to test whether an item is anodised aluminium or die cast zinc with an e-coat, you need to sand some of the colour off to reveal the metal below and then leave it for about half an hour to let the aluminium oxidise and create a passive protective layer. This means the reaction should be delayed if its aluminium and occur much faster if its zinc.


If the zinc content is relatively high you will see some fizzing as the zinc reacts. Hydrochloric acid does not dissolve copper but it will dissolve copper oxides, so you may see some evidence of this also.


hydrochloric acid will attack chrome but it will happen more slowly - you won’t see any froth for a minute or so (chromium also has a good passive film of chromium oxide), and when it happens it will be a bit of a non-event, If its immersed it might only show bubbles forming and sticking to the metal. You’re more likely to notice the result after cleaning the object in water where you will be able to see the contrast between the newly revealed nickel layer and chrome on an untested part.

If you’re concerned that the chromium is the dangerous hex chrome, this would be an effective way to remove the top layer of chrome on the electroplate (though the legality of tipping the resulting Chrome Chloride solution down the sink is something you should probably look into.


Whilst nickel does react with both it’s so minimal you’ll be lucky to notice anything even after many minutes.

Stainless Steel

Stainless Steel is the same as Nickel. 300 series stainless steel shows no reaction, and the 400 series USUALLY won't show a reaction, or it'll be very limited.


There is A LOT of information to take in from this article so to finish up I’ll leave you with a quick table about the most likely metals encountered by your parrots in an unsupervised environment (i.e. cage or aviary). Along with a few online resources for further research. Good luck and safe parrot keeping!



Magnetic Status



Reaction with HCl

Reaction with CuSO4

stainless steel

300 series non-magnetic, 400 series partially magnetic


not commonly used but available

no visible reaction

no visible reaction

nickel plated steel



relatively common - generally quick links, chain and O-rings

reacts - but very hard to tell by eye

displacement will take a long time

anodised aluminium



used often for bell, keys and other coloured metal on toys

delayed reaction but extremely vigorous after a minute or two

delayed reaction, but after about a minute displacement should happen quickly

chrome plated steel



sometimes used for chain

small reaction that is hard to see, underlying nickel will be visible afterwards though


solid or plated brass



common for bells and mechanical parts

if high in zinc it will react gently. Copper oxide may dissolve into the solution

Some displacement of zinc possible but difficult to tell

zinc-plated steel



most common metal used - quick links, chain and O-rings

vigorously reacts

displacement will happen very quickly

zinc-galvanised steel


extra bad

common in wire & fasteners intended for outdoor use (hinges, bolts etc.)

vigorously reacts

displacement will happen very quickly

zinc die casts



often used for complicated parts like bells, especially large ones on boings

vigourously reacts

displacement will happen very quickly




can sometimes be found in bells

doesn't react at all

doesn't react at all



DIY Nikel Testing Kit - these are available from dermatologist or pharmacists since nickel is a common allergen for people. The kit consists of two small bottles of clear fluid. When mixed together in the presence of nickel, a pink colour results. It has quite a high sensitivity though and of course does not rule out other types of metals present.

DIY Lead Detecting Kit - There are several very affordable do-it-yourself lead test kits to be found online or from hardware & paint stores – some of which can be used on plastic and ceramics as well as paint or metal. However before you go out and buy one you should do a search online for reviews and to learn more about them. The test kits are not all created equal and none are infallible.

You Tube- Testing For Zinc - Below are a series of you tube videos by Phoenix Blackthorn, a parrot owner in the US. The explanations for the reactions are not always correct but it does give you an idea of what to expect if you do your own experiments. BTW – the last metal tested is chrome-plated steel.

Pt 1:

Pt 2:

Pt 3:

You Tube - Aluminium foil reacting with hydrochloric acid – This is a great demonstration. It also demonstrates how to collect the hydrogen coming off the reaction, which is another way to gauge the reactivity of your mystery metal.

There are loads more relevant chemical reactions shown on you tube if you want to have a hunt around.

Science - This is an ugly website but with good basic explanations about the Reactivity Series:

Helpful explanations of the Restriction of Hazardous Substances Directive

Toxins - This is a good, relatively recent article on bird toxins:

Lead & Cadmium in Consumer Products

These are a couple of places that go into more detail about lead and cadmium in consumer products:

Science Based Consumer Product Safety Website