Safe and Unsafe Woods
When making chews, toys, houses, platforms and other things for your hamsters, you will need to choose a safe wood to use, which can be confusing. Some woods aren’t suitable for hamsters as they may be irritants or allergens, or in rare cases, toxic. You might also want to know if you can give your hamster branches from outside, and how you should prepare them. This article aims to help you choose and prepare suitable woods for your hamsters.Safe Woods
The following woods are considered non-toxic/not likely to cause any adverse effects. This is a very conservative list and there are certainly likely to be woods which are safe but are not on this list. This is because the topic of safe woods for rodents is very under-researched and there is little reliable information available. I have restricted this list to those woods with the strongest evidence for their safety, especially those that are already commonly used for rodents.
- Alder
- Apple
- Aspen
- Balsa
- Bamboo*
- Birch (silver or downy)
- Fir (kiln-dried)**
- Grape
- Hazel
- Linden aka basswood
- Pear
- Pine (kiln-dried)**
- Quince
- Spruce
- Willow***
*But may produce sharp splinters when chewed. Use with caution.
**Avoid pieces with visible resin.
***Willows contain varying amounts of salicin in their bark. Willow specifically prepared for use by pets (e.g the willow sticks or toys sold by pet shops) is safe but it’s better to avoid using willow collected yourself unless you have researched the specific species enough to be confident using it.
Unsafe Woods
The following woods may be unsafe and are best avoided, especially those in red. As a general rule, you should also avoid any woods which are highly aromatic or contain oil/sap because these oils are very often irritants and sometimes have toxic effects. This list is not exhaustive.- Elderberry
- Eucalyptus
- Box
- Cashew
- Cedar
- Citrus woods, including lemon, lime, mandarin and others
- Dogwood
- Fig
- Horse-chestnut
- Juniper
- Laburnum
- Maple
- Oak*
- Oleander
- Privet
- Stone fruit tree woods, including cherry, plum, apricot and others
- Teak
- Walnut
- Yew
*However cork tunnels, branches etc sold for pets are safe, although they are derived from an oak species.
There are many woods left out of both these lists because there is simply no strong evidence either way. Some woods are also left off because they are very exotic and hardly ever found in the UK or US. Don’t assume that because a wood isn’t on the unsafe list, it is necessarily safe.
Man-made/engineered woods: plywood, MDF, chipwood, hardboard, OSB etc.
These tend to be unsafe because the glues used to bond the woods may be harmful. Some types of man-made wood also contain formaldehyde which is a toxin.Some types of plywood, MDF or hardwood are safe to use for the smooth walls of a cage, which a hamster is very unlikely to chew, but not platforms, houses or anything else with exposed edges. If using sheet materials for cages, only use materials which specify they contain low levels of formaldehyde. Ideally also paint or seal the wood to protect it against moisture.
In the past it was common to construct DIY cages of melamine-faced chipboard or MDF. Recently this has become less popular as the hamster community became aware that melamine is potentially toxic if swallowed. Although the chance of a hamster being poisoned by smooth melamine walls in a cage is quite low, the risk cannot be ruled out. If you choose not to use melamine-faced wood, you might be able to find sheet wood with a plastic or foil veneer instead. Many IKEA products which are used for DIY cages (including the Platsa and Linnmon) are not made with melamine and therefore can be safely used.
There is such a thing as non-toxic plywood that is safe for hamsters to chew, however it seems very hard to find and I am not aware of any suppliers currently.
Buying Wood
Ordinary timber that you can buy from most DIY stores is generally either whitewood (usually spruce) or redwood, and either treated or untreated (also known as sawn kiln-dried). Look for untreated (sawn kiln-dried) whitewoods and avoid redwoods or treated woods. Treated tends to be slightly greenish in colour whereas untreated whitewood should be a pale yellow.Commercially available softwoods (pine and fir) are almost always kiln-dried but avoid any that aren’t.
If buying other types of wood, ensure they are a safe type and untreated.
Collecting wood from outside
When collecting wood from outside, be very sure of its type before giving it to your hamsters, and if you’re not certain, leave it behind. You should also be sure that it hasn’t been sprayed or treated with anything toxic, which means you often won’t be able to use wood from public areas such as parks. It’s better to source wood from your own trees if you have any, or trees belonging to family or friends who know about any potential treatments. Avoid rotten or infested wood, as well as driftwood.Once you have collected some safe wood, you need to clean it as it may be carrying germs from outside. Thoroughly scrubbing it in hot, soapy water should remove any visible dirt and most germs. If you want to be extra sure you could pour boiling water over the wood. You can also bake the wood, ensuring the surface gets very hot to kill any germs and bugs that may be hiding in the wood. This is particularly important if the wood is very craggy or uneven and therefore difficult to clean with water alone.
I would avoid using softwoods such as pine or fir collected directly from outside. Although these are on the safe list, in their natural state they can contain aromatic oils which may be harmful. These are reduced to safe levels by the kiln drying process which almost all commercially sold wood undergoes. There is debate over the safety of kiln-dried softwood shavings for bedding, which isn’t the topic of this article, however solid kiln-dried softwood is certainly safe to use for things like platforms, toys and houses.
Repurposed wood or wooden items
Sometimes wooden items intended for a different purpose, such as craft blanks, chopping boards, shelves, wood salvaged form old furniture etc can be repurposed for hamsters. The same principles apply as when you are buying wood: you should make sure it is a safe type of wood and untreated (or at least treated only with safe substances). Unfortunately this information can often be difficult to find.Avoid using pallet wood, as it tends to be heavily treated with substances which may be unsafe.
Sources
- Woods, Tree Branches & Twigs, eGerbil via archive.org
- Trees_shrubs_herbs_plants, Version 4 (PDF from the Facebook Group Degu MANIA) - You will need to join the group to view this file.
- Wood Allergies and Toxicity, The Wood Database
