I'm glad to see other airsofters pursuing serious laboratory testing on their products.

I have had to identify plastics on many occasions in my practice of product design and I find it can be quite helpful to burn small samples of plastics in question. The smell of smoke given off from various compounds is quite distinct as our noses are very good sensors. You can also compare sample odours against known compounds. Take care not to snort deep lungfulls of smoke as it is dangerous in high quantities. Just a short sniff is necessary to identify many common organic compounds. I find lighting a very small shaving is sufficient to produce the necessary wisp of smoke.

Off the top of my head I can list off several materials which are very recognizable and easy to describe:

-polyolefins (polyethylene, HDPE): smells close to candle wax which is actually very low density polyethylene
-Delrin (acetal): smells a little sour with a sharp odour which slightly burns (in safe small quantities). Burning delrin evolves formaldyhyde compounds which sting a little
-nylon: smells like burning hair. Nylon is evolved from milk proteins I think which is why it smells like burning body stuff (ew). Sometimes burning nylon can have a smell of an ironed shirt (nylon shirts?)
-styrene, polystyrene, ABS: all smell similar because of their commonality. Compare this against the smell of burning CD cover plastic (styrene). ABS samples can be shaved off some plumbing pipe
-polyesters: smells like burning electronics (polyester lacquers are commonly used to insulate magnetic coils and circuit boards)

I wouldn't be too surprised of bb manufacturers have been claiming that their PS bbs were exceedingly biodegradable. Styrene compounds are very easy to mould and very cheap. I would think that truly biodegradable materials may be difficult to mould since so little work has been done to create short lived plastic items up until now.

Perhaps the burn test could be used by low tech airsofters with their nasal spectrometers.


Kind regards,

Carlton Chong