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Tuatara: Volume 5, Issue 3, March 1955

Use of Barrier-Cream in the Dissection Laboratory

Use of Barrier-Cream in the Dissection Laboratory

Formalin, now the most abundantly used preservative for bulk zoological material, was introduced following the simultaneous discovery of its value for this purpose by Hermann and by Blum independently in 1893. It is difficult to-day to appreciate that its use was much debated and in question even after 1900. The solution of the pungent formaldehyde in water was variously called formalin, formol, and formalose, each being a commercial name. Its efficiency, cleanliness, general stability, economy in use, availability and freedom from custom control have combined to favour formalin over alcohol as a bulk preservative; but its effect on the skin of a person handling formalin-preserved material has always offset its many other advantages.

There is a wide range in this reaction to formalin, from those persons who seem essentially immune from its effects in low concentrations, such as after preserved material has been subjected to prolonged washing, to those unfortunates who are highly sensitive and develop a rash even on areas of skin, such as the face, not actually in contact with formalin-solution. These are extremely rare; but commonly it is found that sensitivity to formalin increases with time. The reaction shows on the hands. The skin becomes dry, grained, it splits and the quick round the nails splits, the nails become hard, and ultimately a slight general red rash may appear.

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Such effects from formalin were previously countered by prolonged washing of specimens before use, repeated washing of the hands, and by palliative treatment with glyerine and rosewater, and lanoline. Too frequently, even in spite of such care, it was necessary to stop work on formalin-preserved material. The sensitivity would remain high, even ten years later. Recently the washing of specimens in solutions of urea or hypochlorite was practised, but while helpful, such washings are no complete safeguard.

The subject of reactive dermatitis has been important in industry and much researched into. During the early war years, a form of protective hand-cream was discovered. The hands are washed clean, carefully and thoroughly smeared with a thin coat of the protective cream. This rapidly dries to an invisible layer which, properly applied, acts for three or four hours as a complete protection against a wide range of harmful substances. They are termed ‘barrier’ creams, and fortunately one such cream gives full protection to the hands against the effects of formalin. This cream, a so-called ‘wet’ cream, was introduced into general use in our zoology laboratories this year with so far complete success for a large number of students. After much dissection-work on washed material, the skin of the hands remains soft, smooth, and without sign of splitting or of cracking. There is no indication of tingling or other sensations. One person with a long-standing acquired hypersensitivity has been able to handle formalin-preserved material without discomfort for the first time in ten years.

It appears that a suitable barrier-cream now removes one of the major disadvantages of formalin as a preservative.