Rosin, maleated

Endpoint summary

Description of key information

Not irritating to skin but capable of causing severe eye irritation. Low vapour pressure precludes inhalation exposure.

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Adequate information exists to characterise the skin and eye irritation potential of Rosin Adducts and Rosin Adducts Salts. These are formed when rosin reacts with maleic anhydride (or maleic acid) or fumaric acid yielding a maleated rosin adduct or a fumarated rosin adduct, respectively; the rosin adduct salts are simply the rosin adducts that have been reacted with an appropriate base. The available data includes results of tests conducted using Rosin, fumarated, Rosin, maleated and Tall oil, maleated (an analogue of Rosin, maleated). Additionally, key skin corrosion data is available for Resin acids and rosin acids, maleated, potassium salts (CAS# 85409-27-4). This information is summarised below.

Skin irritation / corrosion

In a primary dermal irritation study, six young adult New Zealand white rabbits were exposed to 0.5 g of Rosin, fumarated applied for 4 hours under semi-occluded contact to intact skin (Life Science Research, 1991b). Methods used in this study were compliant with current guidelines (OECD 404). Animals were then observed for a period of 72 hours post-treatment. Irritation was scored. Mean erythema and edema scores for 24 to 72 hours were observed 0 in intact rabbit skin exposed to the test material under semi-occluded contact for 4 hours. Based on these findings, Rosin, fumarated was not considered to be a skin irritant to rabbits, and presents a low skin irritation hazard.

In a primary dermal irritation study, three New Zealand White rabbits were dermally exposed to 0.5 grams of Rosin, maleated for 4 hours using a semi-occlusive dressing (Life Science Research, 1991a). Animals then were observed for 72 hours. Mean erythema and oedema scores were calculated for the 24 to 72 hour time period. Mean erythema score (24 to 72 hours) was 0.1 and mean oedema score (24 to 72 hours) was 0. In this study, Rosin, maleated was not a dermal irritant.

In a skin irritation study with Tall oil, maleated (an analogue of Rosin, maleated) six young adult New Zealand white rabbits were exposed to 0.5 g of Century PB 84 applied for 3 minutes (semi-occluded), 1 hour (occluded), or 4 hours (occluded) to intact skin (White Eagle Toxicology Laboratories, 1993). A mean erythema score of 0.33 and a mean edema of 0 were calculated 48 hours after exposure. Based on these findings, Century PB 84 (Tall oil, maleated) was not considered to be a skin irritant to rabbits, and presents a low skin irritation hazard.

In a GLP-compliant, key Guideline (OECD 431) In Vitro skin corrosion study (Mare, 2014), the test material (Resin acids and Rosin acids, maleated, potassium salts (CAS# 85409-27-4) was applied to the stratum corneum of an epidermal model (SkinEthicsTM RhE; 2 epidermis units per test substance) for 2 different exposure periods: 3 minutes and 60 minutes. Exposure to the test material was terminated by rinsing with D-PBS with Ca+2/ Mg+2. KOH 8N was used as the positive control and sterile ddH2O was used as the negative control. The test material, negative control, and positive control met the acceptance criteria for this assay. Cell viability (expressed in terms of percentage compared to the viability of the negative control (set as 100%)) was observed to be 107.26 % after 3 minute exposure and 173.42 % after 60 minute exposure to the test material. On the basis of the results obtained in the skin corrosion assay, Resin acids and Rosin acids, maleated, potassium salts was considered to be non-corrosive.

In a skin corrosion study (Chelab, 2020), reconstructed human epidermis (EpiDerm) was exposed to the test material (Resin acids and Rosin acids, maleated, sodium salts (CAS# 68201 -60 -5)), for 3 minutes at room temperature, and 60 minutes at 37 °C, in duplicate for each time of exposure. The exposure of the insert to the test substance was carried out for 3 minutes at room temperature and for 60 minutes at and 5% CO₂. After treatment the inserts were rinsed with DPBS and incubated with MTT solution in order to evaluate cell viability which is a direct measure of the corrosion potential of the test substance. Under these conditions, the test substance resulted corrosive: A combination of optional Sub-categories 1B and 1C.

Eye irritation

The eye irritation potential of Rosin, fumarated was evaluated after instillation of 0.1 g into the eye of one New Zealand White rabbit (Life Science Research, 1991c). The animal was observed and then terminated 5 hours after application. After 5 hours, the substance was found to be a severe eye irritant, and further testing was therefore not warranted.

Respiratory Tract Irritation

No studies were identified, however a low vapour pressure indicates that exposure via this route is unlikely.

Justification for classification or non-classification

Not classified for skin irritation according to EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008 or UN Globally Harmonized System of Classification and Labelling of Chemicals (GHS). Classified for eye irritation according to EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008 and UN Globally Harmonized System of Classification and Labelling of Chemicals (GHS), Eye Irritation Category 1.