LINOLEIC ACID
Flammability | 1 | |
Toxicity | 0 | |
Body Contact | 2 | |
Reactivity | 1 | |
Chronic | 2 | |
SCALE: Min/Nil=0 Low=1 Moderate=2 High=3 Extreme=4 |
Drying oils are characterized by high levels of fatty acids One common measure of the
siccative (drying) property of oils is iodine number. Oils with an iodine number greater
than 130 are considered drying, those with an iodine number of 115- 130 are semi- drying
oils and those with an iodine number of less than 115 are non- drying oils The " drying" ,
" hardening" , or, more properly, " curing" of oils is the result of an exothermic
reaction in the form of autoxidation Oxygen attacks the hydrocarbon chain, touching off a
series of addition reactions. As a result, the oil, forms long, chain- like a vast polymer
network molecules, resulting in a vast polymer network. Over time, this network may
undergo further change. Certain functional groups in the networks become ionised and the
network transitions from a system held together by nonpolar covalent bonds to one governed
by the ionic forces between these functional groups and the metal ions present in the
paint pigment. In oil autoxidation, oxygen attacks a hydrocarbon chain, often at the site
of an allylic hydrogen (a hydrogen on a carbon atom adjacent to a double bond). This
produces, a free radical a substance with an unpaired electron which makes it highly
reactive. A series of addition reactions ensues. Each step produces additional free
radicals, which then engage in further polymerization. The process finally terminates when
free radicals collide, combining their unpaired electrons to form a new bond. The
polymerisation stage occurs over a period of days to weeks, and renders the film dry to
the touch. . Used in surface coatings, emulsifiers and vitamins; manufacture of driers.
Occurs as glycerides in vegetable oils.
C18-H32-O2, "9, 12-octadecenoic acid, (Z)-", "9, 12-octadecenoic acid, (Z)-", "9, 12-
linoleic acid", "9, 12-linoleic acid", "cis, cis-9, 12-octadecanoic acid", "cis, cis-9,
12-octadecanoic acid", "cis-9, cis-12-octadecanoic acid", "cis-9, cis-12-octadecanoic
acid", "9, 12-octadecadienoic acid, (Z, Z)-", "9, 12-octadecadienoic acid, (Z, Z)-",
"leinoleic acid", "telfairic acid", "Polylin No. 515", "Emersol 310, 315", "drying oil",
"polyunsaturated fatty acid", "unsaturated fatty acid", "omega-6 fatty acid"
None
The material has NOT been classified as "harmful by ingestion". This is because of the lack of corroborating animal or human evidence. The material may still be damaging to the health of the individual, following ingestion, especially where pre-existing organ (e.g. liver, kidney) damage is evident. Present definitions of harmful or toxic substances are generally based on doses producing mortality (death) rather than those producing morbidity (disease, ill-health). Gastrointestinal tract discomfort may produce nausea and vomiting. In an occupational setting however, unintentional ingestion is not thought to be cause for concern.
Although the liquid is not thought to be an irritant, direct contact with the eye may produce transient discomfort characterized by tearing or conjunctival redness (as with windburn).
Skin contact is not thought to have harmful health effects, however the material may still produce health damage following entry through wounds, lesions or abrasions. There is some evidence to suggest that the material may cause moderate inflammation of the skin either following direct contact or after a delay of some time. Repeated exposure can cause contact dermatitis which is characterized by redness, swelling and blistering. Entry into the blood-stream, through, for example, cuts, abrasions or lesions, may produce systemic injury with harmful effects. Examine the skin prior to the use of the material and ensure that any external damage is suitably protected.
The material is not thought to produce adverse health effects or irritation of the respiratory tract (as classified using animal models). Nevertheless, good hygiene practice requires that exposure be kept to a minimum and that suitable control measures be used in an occupational setting. Inhalation hazard is increased at higher temperatures. Not normally a hazard due to non-volatile nature of product. Inhalation of oil droplets/ aerosols may cause discomfort and may produce chemical pneumonitis. Fine mists generated from plant/ vegetable (or more rarely from animal) oils may be hazardous. Extreme heating for prolonged periods, at high temperatures, may generate breakdown products which include acrolein and acrolein-like substances.
Limited evidence suggests that repeated or long-term occupational exposure may produce cumulative health effects involving organs or biochemical systems. Repeated ingestion of linoleic acid, by man produces changes in platelet function tests. Animals tests show weight loss, progressive secondary anaemia, leukopenia and damage to erythrocyte and platelet membranes.