4-hydroxy-3-methoxycinnamic acid

Endpoint summary

Description of key information

Ferulic acid is a well-known as an allelochemical which is widely distributed in plants. Therefore numerous publications attempting to study and explain its allelopathic effects are available.

However, few of them are useful to allow an ecotoxicological hazard assessment as required by the REACh regulation. Indeed these publications do not meet the basic general principles for a CLP classification or an hazard assessment.

 

Nevertheless, among these publications, data were found for each trophic levels i.e primary producers (algae), primary consumers (invertebrates) and secondary consumers (fish).

 

 

For the fish:

Only one study was found following the bibliographic research. In this study, several compounds (more than 4000) were tested at an initial concentration of 5 mg/L. Test were conducted for a 24-hour period at a water temperature of 55 deg. F on larvae of the Sea lamprey (Petromyzon marinus) or on rainbow trout or on bluegill sunfish. With the Ferulic acid at 5 mg/L no effect were recorded after 24 h of exposure. This publication does not cover the essential principles of the OECD guideline test (i.e. only 24 hours exposure, test performed on larvae, concentration etc…). However as there is no other data found on the fish with the ferulic acid this study was used for this trophic level.

 

For the invertebrates:

Only one study close to the aim of the OECD standard guideline was found. In this study, the molluscicidal effect of the ferulic acid was investigated. Snails attractant pellets (SAP) were prepared with different active molluscicidal components including ferulic acid. The mortality data were observed after every 24h up to 96h. The 96h LC50 for the ferulic acid was 1.17%.

It is not possible to determine the concentration in mg/L of the amount of ferulic acid used. The concentration is expressed as % and this percentage cannot be linked to a concentration in mg/L, therefore this cannot be useful for assessment.

 

For the Algae and other aquatic plants:

Two studies on Lemna species were found.

In the first study (Ramirez et al 1987), Lemna gibba L. G3, (duckweed) was used as a bioassay organism to test the allelochemical effects of salicylic acid , ferulic acid , and umbelliferone. Growth rate, dry weight and total chlorophyll production were measured after seven days of growth. The bioassay procedure used E medium with and without sucrose in Erlenmeyer flasks plus the selected concentration of allelochemical (100 up to 1000 µM). Even though the main objective of this research was to study L. gibba G3 as a bioassay for allelochemicals and to consider any impact on chlorophyll production as a potential indicator of interference, this study gives useful data for hazard assessment of Ferulic acid as required by REACh regulation.

Therefore as a result, in medium without amendment (sucrose and tartaric acid), the NOEL for the growth rate, dry weight and total chlorophyll was 97 mg/L (i.e.500 µM).

 

In the second study, the effect of stock-culture period on the sensitivity of the Lemna bioassay to four different phenolic substances was evaluated. The sensitivity of the bioassay interacted with the stock-culture period of 11, 14, or 18 days. After a seven-day test, ferulic acid with a concentration of 9.7 mg/L (0.05 mM) significantly reduced the number of fronds and the dry weight compared with the untreated control when the stock-culture period had been exactly 14 days. The two higher concentrations (0. l and 0.25 mM) showed stronger inhibition.

 

Two studies involving a standard algae species were found i.e. Pseudokirchneriella subcapitata and Microcystis aeruginosa.

In the first study (Rui et al 2016), the goal was to investigate the effects of allelochemical ferulic acid on a series of physiological and biochemical processes of blue-green algae Microcystis aeruginosa, in order to find sensitive diagnostic variables for allelopathic effects. M. aeruginosa, were exposed to Ferulic acid in MA medium at a series of concentration of 60.1, 91.2, 135.8, 201.8, 302.6, 450.1, 673.2 and 1003 mg/L.

The cell density was investigated as well as several biological effects as the membrane integrity, Membrane potential, Esterase activity Chlorophyll a content and Interferences on photosynthetic activities. Under the tests conditions, Ferulic acid exposure inhibited the growth of blue-green algae Microcystis aeruginosa. The 48h-EC50 and the 96h-EC50 were 442 mg/L and 211 mg/L (i.e. 2.28 mM and 1.09 mM respectively) based on the biomass (cell density). Furthermore this algae cell density was significantly suppressed by Ferulic acid (in the range 0.31 -5.17 mM) only after 48 h exposure therefore the LOEC is determined to be 60.1 mg/L.

In the second study (Schrader et al 1998), the main objective was to screen a wide range of commercially available natural compounds for selective cyanobacterial algicides. In this study, the toxiciy of several compounds including Ferulic acid towards algal culture with cyanbacteria (Anabaena sp and Oscillatoria chalybea ) and green algae (Selenastrum capricornutum and Pediastrum simplex) was investigated.

Thus, for the Species: Pseudokirchneriella subcapitata, Pediastrum simplex and Anabaena sp., the LOEC (5 d) was found to be 194 mg/L (1000 µM) based on the population growth rate. For the Species Oscillatoria chalybea, the LOEC (5 d) was 0.194 mg/L (1 µM) based on the population growth rate. According to the high differential sensitivity between the cyanobacteria Oscillatoria chalybea and the other species (Pseudokirchneriella subcapitata, Pediastrum simplex and Anabaena sp), and also the other study available ( Rui et al 2016), its LOEC is not considered as representative of the algal or cyanobacteria.