Characterisation of vumba and ubumba clays used for cosmetic purposes

Abstract

HOW TO CITE:Morekhure-Mphahlele R, Focke WW, Grote W. Characterisation of vumba and ubumba clays used for cosmetic purposes. S Afr J Sci. 2017;113(3/4) FUNDING:Tshwane University of Technology Two traditional cosmetic clays bear similar names in different local South African languages: vumba (Tshivenda) and ubumba (isiZulu). The wet clays are applied topically for cosmetic purposes by the respective indigenous peoples. Six samples from two South African provinces were characterised using X-ray diffraction, X-ray fluorescence spectroscopy, Fourier transform infrared spectroscopy, thermal gravimetric analysis and scanning electron microscopy. It was found that the samples differed widely with respect to mineralogy and chemical composition. This finding raises the possibility that texture characteristics during application on the skin override composition effects. Of concern is the high levels of quartz found in all the samples as it might pose a health hazard; the lowest value for quartz was 11 wt% for vumba, while values for ubumba ranged from 26 wt% to 85 wt%. All samples contained varying amounts of silicates in the form of smectite, kaolin, chlorite and plagioclase. Minor amounts of anatase and rutile were present in some samples. Three samples also contained goethite. All samples were essentially free from the toxic elements As, Pb, Hg, Cd, Se and Sb. However, they did contain low levels of chromium and heavy metals such as Cu, Zn and Ni. The pH values of ubumba slurries were slightly basic, while those of a vumba slurry were slightly acidic. Significance:• Wide ranges of composition appear to be acceptable.• The clays do not contain highly toxic or radioactive elements.• The high levels of quartz present may pose a human health risk.

Physicochemical characterization and In vitro evaluation of the sun protection factor of cosmetic products made from natural clay material

“…[29][30][31] In addition, the loss of ignition (12.55 %) is in agreement with the results reported elsewhere for clay deposits sampled from KwaZulu-Natal and Limpopo provinces of South Africa. 32 The loss of ignition is attributed to organic matter and the value obtained in this study is coherent with kaolinite rich clay, for which 13-14 % loss of ignition is known as a mean value. 33,34 …”

Geochemical and Physicochemical Characteristics of Clay Materials from Congo with Photocatalytic Activity on 4-Nitrophenol in Aqueous Solutions

“…This was in agreement with the results reported by Madikizela et al The GOL sample exhibited the lowest mass loss (8.33 wt %) compared to the other two samples, namely, KAT (12.59 wt %) and KOL (12.04 wt %), implying that GOL contains fewer organic constituents. Furthermore, it has been reported that mass losses are often associated with the oxidation of organic constituents present in the materials . Boulingui et al have also reported that there are major reactions involving loss of H 2 O, CO 2 , and/or organics in clay materials.…”

“…In some part of the world, including the African continent, clays are used for cosmetic purposes. Morekhure-Mphahlele et al . indicated that some clays in the Eastern Cape in South Africa are used for their moisturizing effect.…”

“…Several researchers have studied clay samples from different locations and have provided their usages, including the construction and ceramic industry, − cosmetic, − and removal of pollutants such as pharmaceuticals , from wastewater. Globally, hazardous chemicals including nitrophenol are released into sewages, rivers, seas, and the environment.…”

Natural resources used as folk cosmeceuticals among rural communities in Vhembe district municipality, Limpopo province, South Africa

“…As stated by the participants, it is used for skin protection from sun and insect bites. The cosmeceutical value of ochre has been recorded in several studies [32,33]. In Western Sahara, Volpato et al [34] indicated that Sahrawi refugees apply red ochre around their eyes to reduce solar radiance.…”