Rose the flowers; for example, about two thousand flowers are required to produce one gram of oil. The main constituents of attar of roses are the fragrant alcohols geraniol and L-citronellol and rose camphor, an odorless solid composed of alkanes, which separates from rose oil. β-Damascenone is also a significant contributor to the scent. Rose hips are occasionally made into jam, jelly, marmalade, and soup or are brewed for tea, primarily for their high vitamin C content. They are also pressed and filtered to make rose hip syrup. Rose hips are also used to produce rose hip seed oil, which is
Essential oil purity, and sometimes related to the toxicity of specific chemical components of the oil. Many essential oils are designed exclusively for their aroma-therapeutic quality; these essential oils generally should not be applied directly to the skin in their undiluted or "neat" form. Some can cause severe irritation, provoke an allergic reaction and, over time, prove hepatotoxic. Some essential oils, including many of the citrus peel oils, are photosensitizers, increasing the skin's vulnerability to sunlight. Industrial users of essential oils should consult the safety data sheets (SDS) to determine the hazards and handling requirements of particular oils. Even certain therapeutic grade