Volumes Of Formalin Research Articles

A South African case study on anatomical embalming for human body donation programmes with toxicological considerations

Body embalming, a practice with deep historical roots across various cultures, forms the backbone of contemporary human body donation educational programmes. In this study, we explored current embalming practices within six South African human anatomical dissection programmes, focusing on the use and volumes of key chemicals—formalin, phenol, and alcohol—and their associated health risks and potential toxicity. We measured and compared aspects of embalming practices such as the duration of body preservation and the annual intake of bodies. Variations in embalming practices and chemical ratios across different South African universities were found. However, the consistent use of formalin, phenol and alcohol were observed across all six programmes. Formaldehyde concentrations used in South African dissection programmes were within the generally acceptable international range. Regarding arterial embalming, South African dissection programmes showed widespread adherence to international embalming practices, with one programme using a substantially lower concentration of formalin. The dual nature of formaldehyde as both an effective preservative and a recognised carcinogen was underscored in relation to human health regarding chemical toxicity. Phenol, like formaldehyde, was consistently used as it is important for the inhibition of bacterial and fungal growth. Alcohol was also consistently used, but there was much greater variation in its volume across South African institutions. Our data showed a slight positive relationship between storage duration and the volumes of formalin and phenol in human embalming fluid. South African regulators enforce stricter exposure limits than those set by the World Health Organisation and various European agencies. While South African institutions operate within internationally acceptable ranges of chemical use that both maximise preservation and minimise toxicity, we acknowledge that these data are preliminary. Further investigation is encouraged to ensure embalming practices effectively protect all those involved and support the educational goals of human anatomical dissection programmes in South Africa.

The effect of immersion formaldehyde fixation on placental weight

The normal reference ranges for placental weight are based on fresh placental status; however, in routine practice, placentas are frequently received in formaldehyde solution prior to the examination. The aim of this study was to assess the effect of formalin fixation on placental weight and the underlying factors affecting this process. We prospectively studied 71 placentas and measured their fresh weight and volume as well as their weight in five consecutive days following fixation in 10% formaldehyde solution. The volume of formalin added primarily and also findings of subsequent macroscopic and histological examination were recorded. The results showed a significant 8.47% (SD 6.33%, p — 0.000) increase in placental weight after formalin fixation for 24 h. This weight change was reversely correlated with fresh placental weight (r — -0.59, p — 0.000) and also had a poor positive correlation with formalin to placenta volume ratio (r = 0.31, p = 0.04). Mean placental weight remained approximately constant in the following days of follow-up. Association between the placental pathologies and changes in weight was also assessed. Our study showed a wide range of changes in placental weight following formalin fixation which is affected by different factors. Knowing them provides a more accurate estimation of the fresh placental weight.

Effects of different concentrations and volumes of formalin on pain response in rats.

Formalin test is commonly used in animal model to assess injury-produced pain response. If the total amount of formaldehyde is fixed, its concentration and volume can be easily adjusted. We evaluated the effect of two sets of three solutions of formalin (one set of same dose of formaldehyde at different concentration and volume, i.e. 2.5%--100 microL, 5%--50 microL, 10%--25 microL, and another set of same volume but at different concentrations, i.e. 2.5%--100 microL, 5%--100 microL, and 10%--100 microL) on the injury-produced pain response in rat. Male Sprague-Dawley rats weighing 250-300 g were used. Following injection of formalin (n = 8 in each group) or saline (n = 6, control), the flinching frequencies and time spent in licking or biting the injected hind-paw in the early phase 1 (0-5 min after injection) and the late phase 2 (20-60 min after injection) were recorded. Sham-injection rats (n = 5) underwent subcutaneous insertion of the needle, but no substance was injected. Flinching in phase 1 and 2 was more frequent in the 2.5%--100 microL and 5%--50 microL groups than in the control group (P < 0.05). Licking (or biting) time in phase 2 in all these three groups was longer than the control group (P < 0.05). In the groups of another set of three different solutions (2.5%--100 microL, 5%--100 microL, and 10%--100 microL), flinching in phase 1 and phase 2 was also more frequent than the control group (P < 0.05). Regarding lick behavior of another set, it occurred more frequently in 2.5%--100 microL group in phase 1 and in 2.5%--100 microL group as well as 5%--100 microL group in phase 2 than the control group (P < 0.05). The 10%--25 microL formalin produces fewer flinching responses than other concentrations. Flinching was a biphasic behavior which was more spontaneous and active than was licking. The volume of formalin was a more important factor than the concentration of formalin in the generation of the active biphasic flinching response in the rat model.