Section 1 - CHEMICAL PRODUCT AND COMPANY IDENTIFICATION

PRODUCT NAME

MAGNESIUM RESINATE

NFPA

PRODUCT USE

Water- proofing, manufacturing, thickener, component of polychloroprene rubber adhesive
formulations, enamels. Intermediate

SYNONYMS

"rosin acids, magnesium salts", "magnesium abietate", "magnesium rosinate"

Section 2 - HAZARDS IDENTIFICATION

CANADIAN WHMIS SYMBOLS

EMERGENCY OVERVIEW

RISK

Flammable.

POTENTIAL HEALTH EFFECTS

ACUTE HEALTH EFFECTS

SWALLOWED

  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.  

EYE

  Although the material is not thought to be an irritant, direct contact with the eye may cause transient discomfort characterized by tearing or conjunctival redness (as with windburn). Slight abrasive damage may also result. The material may produce foreign body irritation in certain individuals.  

SKIN

  The material is not thought to produce adverse health effects or skin irritation following contact (as classified using animal models). Nevertheless, good hygiene practice requires that exposure be kept to a minimum and that suitable gloves be used in an occupational setting.  Open cuts, abraded or irritated skin should not be exposed to this material.  

INHALED

  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.  Persons with impaired respiratory function, airway diseases and conditions such as emphysema or chronic bronchitis, may incur further disability if excessive concentrations of particulate are inhaled.  

CHRONIC HEALTH EFFECTS

  There is limited evidence that, skin contact with this product is more likely to cause a sensitization reaction in some persons compared to the general population.  Long term exposure to high dust concentrations may cause changes in lung function i.e. pneumoconiosis; caused by particles less than 0.5 micron penetrating and remaining in the lung. Prime symptom is breathlessness; lung shadows show on X-ray.  Rosin (colophany) has caused allergic contact dermatitis in solderers using resin flux-  cored solders, can be a sensitiser for strings players, and has caused dermatitis after use in adhesive tapes [NIOSHTEC]. It is found in many products that commonly come in contact with the skin, including cosmetics, sunscreens, veterinary medications, adhesives,  sealants, polishes, paints and oils. Industrial use of rosins (both natural and modified) is common and they are found in such products as printing inks, cutting fluids, corrosion inhibitors and surface coatings. High-quality gloss paper may also be coated with rosin or its derivatives.  The main component of rosin is abietic acid, which by itself is non-sensitising.  Several allergens have been isolated from rosin; these include 15-hydroperoxyabietic acid (15-HPA) and 15-hydroperoxydehydroabietic acid (15-HPDA), a peroxide of dehydroabietic acid. In animal allergic-challenge testing, these two substances are cross-reactive despite differences in molecular weight and unsaturation. Both substances react via a radical mechanism generating structurally similar molecules which give rise to antigens producing the allergic reaction.  Gafvert et al: Arch Dermatol Res 284; 1992; pp 409-413  For a better understanding of the mechanisms of contact allergic reactions, the patterns of cross-reactivity between different resin acid oxidation products were studied.  The 13,14(a)-epoxide and the 13,14(b)-epoxide of abietic acid and 15-HPDA are contact allergens in experimental studies. The b-epoxide of abietic acid has been detected in gum rosins.  Cross reactivity has been observed between the a - and b- epoxides and also between the epoxides and 15-HPA (and also between 15-HPDA and 15-HPA). This can be explained if 15-  HPA forms an epoxide which then reacts with skin protein to generate the complete antigen. Cross-reactivity between the two hydroperoxides might be preceded by the formation of similar alkoxy radicals which further react with skin protein. Cross-  reactivity patterns of resin oxidation products indicate that 15-HPA may react with skin proteins either as a radical or as an epoxide, thus generating different antigens.  Gafvert et al: Chemical Research in Toxicology; 1994; pp 260-266  Esterification of rosin, with polyalcohols for example, reduces allergenic activity although some individuals still are allergic to the polyester. Reduced or diminished reaction to glycerol- and pentaerythritol- esterified rosins, is probably due to the formation of larger molecules (with reduced bioavailability).  Methyl ester of rosins, however, have molecular weights of similar magnitude to the parent rosin and when both are tested in sensitised patients, there is little difference in reactivity.  Shao et al: Contact Dermatitis 28; 1993; pp 229-234  Patch tests conducted using methyl resinate produced a lower level of response than similar tests on the same resin allergic individuals, conducted with glycerol, pentaerythritol and propylene glycol esters of rosin. It was not possible to determine whether those individuals who were methyl resin positive were cross-sensitised or were reacting to a non-specific irritant effect  Private Communication  The main compound formed in glycerol-modified rosins is glyceryl triabietate; lesser amounts of the monoabietate and diabietate are also formed. Whilst the triabietate elicits no or low allergenic activity, the monoabietate has been identified as a contact allergen.  Some individuals react to glycerol-modified rosins: both unmodified abietic acid and the monoabietate have been identified in these modified rosins.  Gafvert et al. Contact Dermatitis; 31 1994; pp 11-17  Rosin modified with fumaric acid or maleic anhydride is often used in paper size. A major product of the paper size in the modification of the rosin is fumaropimaric acid (FPA) which is formed by Diels-Alder addition of fumaric acid to levopimaric acid (l-abietic anhydride), another of the major components of rosin. The allergenic activity of isomers of FPA, tested in guinea pigs is low but maybe present. After prolonged heating, however, FPA is converted to maleopimaric acid (MPA). MPA has been shown to be a potent allergen in previous studies. MPA also forms when abietic acid and fumaric acid are heated together at 220 deg. C and is present in commercially available fumaric acid-  modified rosins. Free abietic acid has also been detected in these modified rosins.  Fumaric acid-modified rosins were shown to elicit positive test results in guinea pigs sensitised to MPA.  Gafvert et al: Nordic Pulp and Paper Research Journal 10: 1995; 139-144.