Use Of Biocides Research Articles

A new method for detecting free liquid moisture on façade surfaces

Liquid water present on the surface of façades is significantly responsible for microorganism growth. This issue became especially important with the increasing use of thermal insulation. The formation of condensation on these façades is often increased due to low surface temperatures [1]. Therefore, the development of a method for controlling the wetness and drying of façades is necessary, since no suitable method is yet available for this purpose. In this paper, the development of an active façade moisture detection system is presented. This system consists of a surface humidity sensor network based on reflection from infrared (IR) radiation, data acquisition and intelligent processing technology. The system is tested and calibrated in the lab for different textured surfaces. Different newly developed coating systems are tested in-situ using this method. These coatings are evaluated with respect to their surface condensation in order to identify the resistance against condensation. The method provides long-term non-destructive measurements of surface wetness. Targeted measures to prevent or reduce the growth of algae can be initiated with the obtained data. In addition, the measured data make a valuable contribution to the development of facade materials and coatings, which have improved drying properties and balance between hydrophilic and hydrophobic surface. As a result, the use of biocides to protect the facade from algae growth can be reduced.

Corrosion of High Carbon Steel by Bacteria under Aerobic and Anaerobic Conditions

The role of microbes in the corrosion of metals is due to the chemical activities (metabolism) associated with the microbial growth and reproduction. A lot of researches have shown that enormous loss of resources and even lives has been experienced in many countries of the world due to corrosion. There is therefore need to device a means of combating this menace so as to save different countries of the world including Nigeria the cost encured due to corrosion. This research has helped to determine the role of bacteria in the corrosion of high carbon steel under aerobic and anaerobic conditions was investigated using sulphate reducing bacteria and other aerobes. A sample of high carbon steel grade of chemical composition: 96% iron (Fe), 1.08% carbon (C), 0.349% silicon (Si), 0.841% manganese (Mn), 0.005% phosphorus (P) and 0.005% sulphur (S), was obtained in the form of steel plate. Eighteen (18) samples of the high carbon steel were prepared. Standard microbiological methods were used to isolate aerobic and anaerobic bacteria isolates. The microbes isolated from the soil included; aerobes (Bacillus species, Pseudomonas species) and anaerobes (Desulfovibrio species, Thiobacillus species). The role of bacteria in the corrosion of high carbon steel was estimated using the weight loss technique and the electrochemical potential measurement technique. Eighteen samples of a high carbon steel of known compositions were exposed to sulphate reducing bacteria under different environments (aerobic, anaerobic and control). The physical and chemical changes were examined and monitored on weekly basis for six weeks. It was observed that the coupons immersed in the media with sulphate reducing bacterium underwent fast activation and numerous corrosion sites were formed on the surfaces. The average corrosion rate for six weeks (42 days) period of time as determined by the weight loss method and electrochemical testing were found to be 0.0004595 mm/year, -0.712 mV in aerobic environment, 0.0005646 mm/year, -0728 mV in anaerobic environment and 0.0004458 mm/year, -0702 mV in the control or reference environment (distilled water environment). High carbon steel was found to corrode more only in the anaerobic environment. In view of this, high carbon steels were found to be relatively more corrosion resistant than mild and medium carbon steels and may be suitable for application in industries such as the petrochemical industry. Therefore, treating the environment with chlorine but with caution as solutions of chlorine gas in water is corrosive to steels while the use of bactericides or biocides to arrest the action of microbes is important.

FUNGICIDE PROPERTIES in Vitro OF CHITOSAN ETHYL CARBAMATE IN THE CONTROL OF VINEYARDS FUNGIES IN CHILE

The grape table is the main fresh fruit export of Chile. However, is affected in the first place by fungal pathogens, resulting between 10 % and 15 % losses in production. The commercial use of biocides has a weakness generating an increase in demand for new antifungal agents. Chitosan and carbamate possess fungicidal properties;therefore the aim of this paper is to analyze the fungicidal activity of chitosan ethylcarbamate. In vitro bioassays were carried out to evaluate the effectiveness of the fungicide to control Botrytis cinerea and Fusarium spp. fungies. The chemical composition of chitosan ethylcarbamate was determined previously. The fungi growth curves and fit with the program DMfit, which uses the Baranyi model to obtain the growth parameters were studied. Then, we estimated the MIC (minimum inhibitory concentration) by a microdilution method. These data were analyzed by simple linear regression. Growth parameters of Fusarium spp shows a growth rate of 1.3 h-1, and Botrytis cinerea of 0.9 h-1, respectively. Chitosan ethylcarbamate with a MIC of 1250 mg/L on Fusarium spp. and B. cinerea a MIC of 1250 mg/L were obtained. Finally, the chitosan ethyl carbamate fungicide, biodegradable, is a more ecological alternative to the conventional fungicides such as Iprodione, Zineb, Nabam, Maneb and the traditional Bordeaux mixture.

Flame sprayed environmentally friendly high density polyethylene (HDPE)–capsaicin composite coatings for marine antifouling applications

Marine biofouling has emerged as worldwide serious problems for artificial marine infrastructures. Among the measures taken so far to solve the abovementioned problems, construction of an antifouling layer has been proven to be effective in offering long-term antifouling performances. Antifouling based on the use of biocides is the most important method in modern maritime industries. While tributyltin (TBT)-based self-polishing coatings are being replaced by other biocide-releasing coatings, the environmental toxicity of these compounds is also under scrutiny. Therefore, there is a significant interest in developing non-toxic technologies. Green biocides can also be extracted from many types of organisms including terrestrial plants, sea creatures and bacteria. The capsaicin was extracted from chili pepper. In this study, flame sprayed high density polyethylene (HDPE)–capsaicin composite coatings were developed for marine antifouling applications. Capsaicin powder were fixed by polymer-based substrate and distributed evenly. Antifouling performances of the films were assessed by examining survival and colonization behaviors of E. coli and Bacillus sp. bacteria and Phaeodactylum tricornutum. Antifouling test indicated excellent antibacterial properties of HDPE–capsaicin composite coatings against both gram-negative Escherichia coli and gram-positive marine Bacillus sp. bacteria. Excellent antifouling performances against bacteria and algae of the thermal sprayed composite coatings give clear insight into their potential applications as environmentally friendly antifouling layers in the marine environment.

Biocides Used as Additives to Biodiesels and Their Risks to the Environment and Public Health: A Review.

One of the advantages of using biodiesel and its blends with diesel oil is the lower levels of emissions of particulate matter, sulfur dioxide, carbon monoxide, among others, making it less harmful to the environment and to humans. However, this biofuel is susceptible to microbial contamination and biodeterioration. In this sense, studies on the use of effective low toxicity biocides are being carried out, and this work aims to present the latest information (2008–2018) available in the scientific databases, on the use of biocides in biodiesel, mainly concerning their toxicity to the environment and public health. The results showed that in relation to the control of microbial contamination, the current scenario is limited, with seven publications, in which the most studied additives were isothiazolinones, oxazolidines, thiocyanates, morpholines, oxaborinanes, thiocarbamates and phenolic antioxidants. Studies regarding direct experiments with humans have not been found, showing the need for more studies in this area, since the potential growth of biodiesel production and consumption in the world is evident. Thus, there are need for more studies on antimicrobial products for use in biodiesel, with good broad-spectrum activity (bactericidal and fungicidal), and further toxicological tests to ensure no or little impact on the environment.

Mixture Toxicity of Methylisothiazolinone and Propylene Glycol at a Maximum Concentration for Personal Care Products

Methylisothiazolinone (MIT) has been used in combination with methylchloroisothiazolinone (CMIT) for cosmetic products such as shampoo, body lotion, and skin care products. The mixture of CMIT/MIT has been found to cause allergic contact dermatitis and is thus no longer permitted for use as a preservative in leave-on cosmetics. However, MIT itself was approved as a stand-alone preservative at a maximum concentration of 100 ppm as the toxicity was derived from CMIT rather than MIT. However, in many countries, allergic skin irritation caused by MIT remains a social concern. In this study, skin irritation was assessed for the presence of MIT, propylene glycol, and their mixture using a 3D human skin model EpiDerm™. Although non-diluted MIT causes serious skin toxicity, skin irritation was not observed at a concentration of 100 ppm, the maximum permissible level for cosmetics and personal care products according to European regulations. Propylene glycol, the most widely used vehicle for MIT, did not cause skin irritation in the 3D skin model. The results are expected to provide information for regulatory policies and guidelines on the use of biocides in consumer products.

Food processing as a risk factor for antimicrobial resistance spread along the food chain

Farms and food industries rely to a large extent on the use of biocides as disinfectants and other antimicrobial agents and preservatives with antimicrobial properties in order to provide food of high microbiological quality and safe for consumers. However, in the last decades it has become apparent that long-term sub-lethal exposure to these antimicrobial agents can exert a selective pressure leading to the emergence and spread of microbial strains with a reduced susceptibility to the used antimicrobials, which can persistently colonize food-processing environments and recurrently contaminate food. In addition, it may induce resistance to unrelated and clinically relevant antibiotics, in a phenomenon known as cross-resistance. This review aims to provide insights on how antimicrobial resistance emergence and spread can be affected by certain food processing activities and to discuss recent research focused on different pathways through which biocides and other antimicrobials could co-select for bacteria resistant to clinically relevant antibiotics.

Organotin contamination in commercial and wild oysters from China: Increasing occurrence of triphenyltin

Organotin contamination in marine environment has been a public concern for many years due to its adverse impacts on biota and human health. This study investigated levels, distribution and health risks of six organotin compounds: tributyltin (TBT), dibutyltin (DBT), monobutyltin (MBT), triphenyltin (TPhT), diphenyltin (DPhT) and monophenyltin (MPhT) in commercial and wild oysters in China. The total organotin in commercial oysters ranged from 251 to 1949 ng Sn g−1 dw (dry weight) >. Two endocrine disruptors TBT and TPhT were detected in these samples with the highest level of 68.1 ± 20.1 ng Sn g−1 dw and 747 ± 7.3 ng Sn g−1 dw, respectively. For wild oysters, the concentrations of total organotins varied from 33.3 to 2671 ng Sn g−1 dw. Butyltins were dominated by TBT with the mean level of 26.1 ± 30.0 ng Sn·g−1 dw and showed no significant spatial variation between the southern and northern coastal zones (p > 0.05). However, compared with the north, phenyltin levels especially TPhT were much higher in the south coastline (246–1484 ng Sn·g−1 dw) due to the wider use of TPhT-based biocides in local mariculture and agriculture. Health risk assessment indicated that a daily exposure of TPhT-contaminated oysters (including commercial and wild ones) may pose adverse threats to human particularly children as the risk quotients (RQ) were higher than 1. Organotin contamination (e.g., TPhT) still occurs in the South China's coastal zones after the TBT ban, which deserves future research and effective measures to protect the marine ecosystem and human health.

Risk assessment of antimicrobial resistance along the food chain through culture-independent methodologies.

Antimicrobial resistance (AMR) represents a major challenge for Public Health and the scientific community, and requires immediate and drastic solutions. Acquired resistance to certain antimicrobials is already widespread to such an extent that their efficacy in the treatment of certain life‐threatening infections is already compromised. To date, the emergence and spread of AMR has been attributed to the use, misuse or indiscriminate use of antibiotics as therapeutic drugs in human, animal and plant health, or as growth promoters in veterinary husbandry. In addition, there is growing concern over the possibility of AMR transmission via the food chain. Food processing environments could act as potential hotspots for AMR acquisition and spread. Indeed, biocide use and exposure to food‐related stresses and food processing technologies could presumably act as selection pressures for increased microbial resistance against clinically relevant antibiotics. Global AMR surveillance is critical for providing the necessary information to form global strategies and to monitor the effectiveness of public health interventions as well as to detect new trends and emerging threats. Surveillance of AMR is currently based on the isolation of indicator microorganisms and the phenotypic characterisation of the strains isolated. However, this approach provides very limited information on the mechanisms driving AMR or on the presence and spread of AMR genes. Whole genome sequencing (WGS) of bacterial pathogens is a powerful tool that can be used for epidemiological surveillance, outbreak detection and infection control. In addition, whole metagenome sequencing (WMS) allows for the culture‐independent analysis of complex microbial communities, providing useful information on the occurrence of AMR genes. Both approaches can be used to provide the information necessary for the implementation of quantitative risk assessment of AMR transmission routes along the food chain.

Antimicrobial Magnesium Hydroxide Nanoparticles As an Alternative to Cu Biocide for Crop Protection.

In agriculture, prolonged use of copper biocides increases the risk of development of Cu resistance and its accumulation in soil, demanding an alternative. In this paper, we report antimicrobial magnesium hydroxide nanoparticles (NPs) as an alternative to Cu biocides with low cytotoxicity. To improved bioavailability, Mg hydroxide NPs were synthesized followed by coating with water-soluble capping agents, trisodium citrate (zeta potential, ξ = -22 mV) or betaine (ξ = +35 mV). Electron microscopy study confirmed the formation of ∼10-nm-sized cubical NPs with citrate and ∼100-nm-sized lamellar NPs with betaine. As-synthesized Mg hydroxide NPs inhibited bacterial growth of X. alfalfae, P. syringae, and E. coli within 4 h. Significant bacterial growth inhibition and killing were observed at 24 h post-treatment. Phytotoxicity studies on tomato plants showed no significant tissue injury. Therefore, Mg hydroxide NPs have the potential to serve as a Cu alternative.

Bacterial species diversity as an indicator of dibromonitrilopropionamide (DBNPA) biocide efficacy.

Microorganism growth in industrial systems is controlled through the use of biocides and biodispersants. There is, however, no simple means of determining the efficacy of these control mechanisms, but it is currently tested using complex bacterial culturing techniques. Biolog Ecoplates® have been used to detect bacterial population changes in various communities. These microtitre plates comprise 31 different carbon substrates (in triplicate) with wells. When a sample is added to the wells, bacteria capable of metabolising the relevant carbon sources respire the substrates, causing the tetrazolium dye in the well to turn purple, indicating a positive result. Hypothetically, the higher the microbial diversity, the more substrates will be utilised and vice versa. The objective of this study was to test this hypothesis, using Biolog Ecoplates® as a potential simple indicator to determine the efficiency of a biocide to control microbial growth in cooling water systems by monitoring the changes in the microbial metabolic pattern. This study proved the hypothesis using Biolog Ecoplates®, indicating that the addition of biocides at various concentrations resulted in fewer substrates being utilised, indicative of a decrease in microbial species diversity.

The Plant Alkaloid Camptothecin as a Novel Antifouling Compound for Marine Paints: Laboratory Bioassays and Field Trials.

The extensive use of copper and booster biocides in antifouling (AF) paints has raised environmental concerns and the need to develop new AF agents. In the present study, 18 alkaloids derived from terrestrial plants were initially evaluated for AF activity using laboratory bioassays with the bryozoan Bugula neritina and the barnacle Balanus albicostatus. The results showed that 4 of the 18 alkaloids were effective in inhibiting larval settlement of B. neritina, with an EC50 range of 6.18 to 43.11μM, and 15 of the 18 alkaloids inhibited larval settlement of B. albicostatus, with EC50 values ranging from 1.18 to 67.58μM. Field trials that incorporated five alkaloids respectively into paints with 20% w/w indicated an in situ AF efficiency of evodiamine, strychnine, camptothecin (CPT), and cepharanthine, with the most potent compound being CPT, which also exhibited stronger AF efficiency than the commercial antifoulants cuprous oxide and zinc pyrithione in the field over a period of 12months. Further field trials with different CPT concentrations (0.1 to 20% w/w) in the paints suggested a concentration-dependent AF performance in the natural environment, and the effective concentrations to significantly inhibit settlement of biofoulers in the field were ≥ 0.5% w/w (the efficiency of 0.5% w/w lasted for 2months). Moreover, CPT toxicity against the crustacean Artemia salina, the planktonic microalgae Phaeodactylum tricornutum and Isochrysis galbana, was examined. The results showed that 24h LC50 of CPT against A. salina was 20.75μM, and 96h EC50 (growth inhibition) values of CPT to P. tricornutum and I. galbana were 55.81 and 6.29μM, respectively, indicating that CPT was comparatively less toxic than several commercial antifoulants previously reported. Our results suggest the novel potential application of CPT as an antifoulant.

One particle, two targets: A combined action of functionalised gold nanoparticles, against Pseudomonas fluorescens biofilms

Attempts to deal with the problem of detrimental biofilms using nanoparticle technologies have generally focussed on exploiting biocidal approaches. However, it is now recognised that biofilm matrix-components may be targets for the disruption or dispersion of biofilms. Here, we show that the functionalization of gold nanoparticles with the enzyme, proteinase-K (PK) led to both biocidal and matrix disruption effects within Pseudomonas fluorescens biofilms and released cells. This study highlights the potential mechanisms underpinning the properties of Proteinase-K functionalized gold nanoparticles. With the emergence of biocide-resistant biofilm-forming organisms, novel nanoparticle strategies may provide the ideal solution for disrupting and inactivating biofilm cells, thereby minimising the use of biocides or antibiotics.

Inhibition of Nitzschia ovalis biofilm settlement by a bacterial bioactive compound through alteration of EPS and epiphytic bacteria

Marine ecosystems contain benthic microalgae and bacterial species that are capable of secreting extracellular polymeric substances (EPS), suggesting that settlement of these microorganisms can occur on submerged surfaces, a key part of the first stage of biofouling. Currently, anti-fouling treatments that help control this phenomenon involve the use of biocides or antifouling paints that contain heavy metals, which over a long period of exposure can spread to the environment. The bacterium Alteromonas sp. Ni1-LEM has an inhibitory effect on the adhesion of Nitzschia ovalis, an abundant diatom found on submerged surfaces. We evaluated the effect of the bioactive compound secreted by this bacterium on the EPS of biofilms and associated epiphytic bacteria. Three methods of EPS extraction were evaluated to determine the most appropriate and efficient methodology based on the presence of soluble EPS and the total protein and carbohydrate concentrations. Microalgae were cultured with the bacterial compound to evaluate its effect on EPS secretion and variations in its protein and carbohydrate concentrations. An effect of the bacterial supernatant on EPS was observed by assessing biofilm formation and changes in the concentration of proteins and carbohydrates present in the biofilm. These results indicate that a possible mechanism for regulating biofouling could be through alteration of biofilm EPS and alteration of the epiphytic bacterial community associated with the microalga. How to cite: Infante, C.D., Castillo, F., Pérez, V., et al. Inhibition of Nitzschia ovalis biofilm settlement by a bacterial bioactive compound through alteration of EPS and epiphytic bacteria. Electron J Biotechnol 2018;33 https://doi.org/10.1016/j.ejbt.2018.03.002.

Heavy Metal Susceptibility of Escherichia coli Isolated from Urine Samples from Sweden, Germany, and Spain.

ABSTRACTAntimicrobial resistance is a major health care problem, with the intensive use of heavy metals and biocides recently identified as a potential factor contributing to the aggravation of this situation. The present study investigated heavy metal susceptibility and genetic resistance determinants in Escherichia coli isolated from clinical urine samples from Sweden, Germany, and Spain. A total of 186 isolates were tested for their sodium arsenite, silver nitrate, and copper(II) sulfate MICs. In addition, 88 of these isolates were subjected to whole-genome sequencing for characterization of their genetic resistance determinants and epidemiology. For sodium arsenite, the isolates could be categorized into a resistant and a nonresistant group based on MIC values. Isolates of the resistant group exhibited the chromosomal ars operon and belonged to non-B2 phylogenetic groups; in contrast, within the B2 phylogroup, no ars operon was found, and the isolates were susceptible to sodium arsenite. Two isolates also harbored the silver/copper resistance determinant pco/sil, and they belonged to sequence types ST10 (phylogroup A) and ST295 (phylogroup C). The ST295 isolate had a silver nitrate MIC of ≥512 mg/liter and additionally produced extended-spectrum beta-lactamases. To our knowledge, this is the first study to describe the distribution of the arsenic resistance ars operon within phylogroups of E. coli strains isolated from patients with urinary tract infections. The arsenic resistance ars operon was present only in all non-B2 clades, which have previously been associated with the environment and commensalism in both humans and animals, while B2 clades lacked the ars operon.

Biocide efficacy and consolidant effect on the mycoflora of historical stuccos in indoor environment

Abstract Investigations are needed to address and optimize the use of biocides and restoration materials with reference to the fungal diversity, which often characterizes cultural heritage surfaces. This work aimed to examine the diversity of fungi responsible of aesthetic decay on the stuccos of the vault of a religious building in Torino (NW-Italy), and to evaluate the sensitivity of the detected set of species to widely used biocidal products (benzalkonium chloride, isothiazolinones, sulphamide derivatives) and their application solvents. The effect of four commercial consolidants on their potential (re-)colonization following restoration interventions was also assessed. Four different deterioration phenomena were related to the occurrence of Chaetomium murale, Stachybotrys chartarum, Penicillium chrysogenum and Sarocladium kiliense, respectively. Surface receptivity to the different species – identified on morphological and molecular bases – was related to slightly different thermo-hygrometric conditions, the distribution of painted surfaces, salts, and local remnants of cellulose poultice used in past restoration interventions. Specific sensitivity to two solvents and ten different biocide treatments was evaluated in terms of inhibition of mycelial growth from transplanted inocula at 9 (T1) and 27 (T2) days after the incubation. The different solvents and biocide products differently affected growth and/or pigmentation of the four species. Only 40% of the ten performed biocide treatments determined the growth inhibition of all the examined species at both T1 and T2. In other cases, inhibition observed at T1 for C. murorum, S. chartharum and S. kiliense, was followed at T2 by the colonization of inhibition zones. The mycelial growth on an oligotrophic culture medium poured with four commercial consolidants was evaluated one year after the incubation. All the species displayed some growth from the inocula, with a scarce biomass being only observed in negative (water) controls and upon one consolidant treatment. The three other products strongly supported a higher growth of at least two of the examined fungal species with respect to negative controls. In conclusion, different sensitivity of each fungal species for most biocidal treatments and stimulation by consolidants indicate that species-specific assays of products are necessary to calibrate and optimize restoration works. In particular, effective inhibition of fungi by biocides, and potential stimulation by consolidants, should be evaluated after several weeks and months, respectively, since short-term monitoring may be misleading.

Multiple drug resistance and biocide resistance in Escherichia coli environmental isolates from hospital and household settings

BackgroundAntibiotic resistance of environmental Escherichia coli in hospitals could be increased due to extensive use of biocides resulting in serious infections. In this study, the prevalence of antibiotic resistance of environmental isolates of E. coli from hospitals and household settings were evaluated and compared. In addition, the association between biocide minimum inhibitory concentration (MIC) and multiple drug resistance (MDR) was investigated.MethodsEnvironmental samples were collected from different homes and hospitals in Amman, Jordan. The isolates were identified phenotypically and by PCR. Antibiotic susceptibility tests and MIC of selected biocides were performed on the isolates. Screening for blaCTX-M group 1 was also performed.ResultsOf 21 E. coli strains isolated, 47.6% were MDR and 67.9% were phenotypically identified as extended spectrum beta-lactamase (ESBL) producers. The occurrence of these ESBL isolates was comparable between household and hospital settings (P > 0.05). The MIC values of the biocides tested against all isolates were well below the in-use concentration of biocides. Moreover, the MICs of biocides were comparable between isolates from households and those from hospitals (P > 0.05). No association was found between MDR and biocide MIC (P > 0.05). Most of ESBL isolates harboured blaCTX-M 1.ConclusionsThe extensive use of biocides in hospitals is not associated with MDR nor does it affect the MIC of biocides against E.coli.

Growth media and assay plate material can impact on the effectiveness of cationic biocides and antibiotics against different bacterial species

There are an increasing number of reports of bacterial strains that are multi-drug resistant. The use of biocides as part of infection control is crucial in helping to combat the spread of these particular strains. Unlike for antibiotics, there are few standardized measuring techniques to understand if an isolate has become more resistant to biocides. This study demonstrates the importance of media composition and plate material on variation and reporting of susceptibility of several bacterial species to specific cationic biocides. It is a useful comparison study to highlight the need to standardize biocide susceptibility testing.

Unlocking the multiple public good services from balanced fertilizers

Fertilizers produce over half of the world’s food and permit less encroachment into pristine lands. Yet, the low uptake efficiency by crop plants causes nutrient losses that drive global change. Mitigating measures have been insufficient to address the problems, and policy interventions, NGO involvement, and RD healthier plants to reduce biocide use; plant robustness to enhance tolerance to abiotic stresses; and increased metabolite production to improve taste and shelf-life. We reflect on raising awareness about these multiple fertilizer-based public good services for realizing several Sustainable Development Goals which can be achieved through a comprehensive nutrient assessment to catalyze transformation in research, policy and industry.

What is the aquatic toxicity of saponin-rich plant extracts used as biopesticides?

Saponin-rich extracts from Quillaja saponaria and Chenopodium quinoa have been registered by US EPA as active ingredients in biopesticides, and extract from tea seed powder, Camellia oleifera has been proposed for biocidal use. If saponin-rich biopesticides are efficient against pests, they are most likely also bioactive in the aquatic environment against non-target organisms. The aim of this study was to conduct an effect assessment of saponin-rich plant extracts by using species sensitivity distributions based on acute toxicity tests. The maximal concentrations protecting 95% of the aquatic species (HC5) of saponins extracted from quillaja bark, tea seed coat and quinoa seed coat were 2.91 ± 1.00, 0.22 ± 0.11 and 22.9 ± 5.84 mg/L, respectively. The 100-fold difference in toxicity between the saponin-rich extracts from different plant species, indicate that saponin toxicity depends on the species it origins from, making "read-across" between saponins a dubious exercise. In addition, the predicted environmental concentrations of different saponins are close to or higher than their water quality standard, which means that the extracts might pose a risk to the aquatic environment if not used cautiously.