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Hi


I would like to hear what do you think about HMDS - hexamethyldisilazane - to preserve smaller specimens (around 1 mm)... Afaik, it preserves the structures of insects even better than the ethanol 70%. At least when we get out the smaller specimens from ethanol 70% they shrink a lot which is not desirable at all. For HMDS it seems they kept the same structure without any shrinkage. The big cons is the highly toxicity of HMDS..

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Of course credit goes to Brian Brown for making this known to dipterists back in 1993, but I have put together a website that goes step by step through the process. We use this all the time - the specimens come out great. But of course the caveats are that it is a very dangerous chemical and proper handling is absolutely required! Anyway - here is the website.

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Thanks, Steve.
I have just found the potential health effects with HMDS contact..

"Inhalation:
Excessive inhalation of vapors can irritate the respiratory tract and possibly lead to fluid accumulation in the lungs. Mild anesthesia has also been reported.
Ingestion:
Toxicity data limited. Not considered a serious hazard although ammonia and hydrous silica compounds may be formed by hydrolysis in the digestive system. Gastrointestinal upset may follow the ingestion of appreciable amounts. Vomiting can present the additional hazard of getting HMDS into the lungs.
Skin Contact:
Moderate irritant, especially to sensitive areas. Alkaline reaction can cause soreness with inflammation in acute cases. May be absorbed through skin.
Eye Contact:
Irritant, may cause severe burns on direct contact with liquid HMDS.
Chronic Exposure:
No information found.
Aggravation of Pre-existing Conditions:
Persons with pre-existing skin disorders or eye problems or impaired respiratory function may be more susceptible to the effects of the substance. "

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For many years I worked with HMDS. Information about the highly toxicity greatly exaggerated.