The Government of Canada conducted a science-based evaluation, called a screening assessment, of 5 substances referred to collectively as the Poly(bios) Group to address the potential for harm to Canadians and to the environment.
Under the Canadian Environmental Protection Act, 1999 (CEPA 1999), the risk posed by a substance is determined by considering both its hazardous properties (its potential to cause adverse human health or ecological effects) and the amount of exposure there is to people or the environment. A substance may have hazardous properties; however, the risk to human health or to the environment may be low depending upon the level of exposure.
Although there is moderate exposure of Canadians to some of the substances in the Poly(bios) Group, they are all considered to have a low risk of harm. Therefore, it is concluded these substances are not harmful to human health or to the environment.
About these substances
This screening assessment focuses on 5 substances: tannins, humic acid, oxidized starch, 2-hydroxy-3-(trimethylammonio)propyl ether, chloride (SEGAC), and guar gum, 2-hydroxy-3-(trimethylammonio)propyl ether, chloride (GEGAC).
These substances were previously evaluated under the Second Phase of Polymer Rapid Screening. However, tannins, humic acid and oxidized starch were identified as requiring further assessment for potential human health risks, and SEGAC and GEGAC required further assessment for potential ecological risks.
Tannins are naturally occurring in the environment. In Canada, they are used in the food, pharmaceutical, cosmetic, fabric and textile industries.
Humic acid also occurs naturally in the environment. It is found in soils, coals, peats, and water ecosystems. It is used in cosmetics and natural health products.
Oxidized starch, SEGAC and GEGAC do not occur naturally in the environment. In Canada, oxidized starch is used in the paper and textile industries and can be used as a food ingredient. SEGAC is used in the pulp and paper industry, and GEGAC is used in the personal care products industry.
Industry data collected by the Government indicates that the substances are all imported into Canada, and tannins and oxidized starch are also manufactured in Canada.
Exposure of Canadians and the environment
Canadians may be moderately exposed to tannins as they are naturally occurring in a number of botanical sources. Tannic acid can be used as a food additive; however, based on the limited food sources, exposure from this use is expected to be negligible.
The majority of exposure to humic acid comes from its natural occurrence in soil and water. Due to the nature of the substance, direct and indirect exposure to humic acid is expected to be negligible.
The industrial use of oxidized starch is not expected to result in direct consumer exposure to the substance. Indirect exposure is also not expected. Although direct exposure to oxidized starch from the diet is expected, the substance is considered to be of low hazard and exposure is unlikely to pose a risk to human health.
Exposure for both SEGAC and GEGAC was established as high; however, since the human health hazard for the substances was determined to be low, the exposure is unlikely to pose a risk to human health.
SEGAC and GEGAC may be released into the environment through wastewater effluents, however, significant removal through wastewater treatment occurs and exposure is therefore limited.
Key health and ecological effects (hazard)
Tannins and humic acid are considered to be of low hazard as they do not contain any groups or features that are known to be associated with adverse human health effects.
Oxidized starch is also considered to be of low hazard. Although it contains aldehyde groups that have been associated with genotoxic (adversely affects genetic material) and cytotoxic (adversely affects cells) effects, the groups present in oxidized starch are found to be at very low amounts. Therefore, any toxicity associated with oxidized starch is expected to be very low.
SEGAC and GEGAC are expected to show moderate to low toxicity to aquatic organisms, and low toxicity towards sediment-dwelling species in natural environments.
The ecological effects of tannins, humic acid and oxidized starch, and the human health effects of SEGAC and GEGAC, are addressed in the Second Phase of the Polymer Rapid Screening.
The potential for ecological risk was found to be low for all 5 substances.
The substances are considered to be of low hazard to human health, therefore the risk to human health is low.
Considering the information presented in this assessment and in the Second Phase of Polymer Rapid Screening Assessment, there is low risk of harm to organisms and the environment from these substances.
The Government concluded that tannins, humic acid, oxidized starch, SEGAC, and GEGAC are not harmful to human health at current levels of exposure.
The Government concluded that these 5 substances are not entering the environment at levels that are harmful to the environment.
Important to know
These 5 substances can be found in certain products available to consumers. Canadians should follow any safety warnings and directions on product labels and dispose of products responsibly.
Canadians who may be exposed to these substances in the workplace can consult with their employer and an occupational health and safety (OHS) representative about safe handling practices, applicable laws, and requirements under OHS legislation and the Workplace Hazardous Materials Information System (WHMIS).
