Ethanol

Toxicity to aquatic algae and cyanobacteria

Description of key information

FRESHWATER - RELIABLE

Chlorella vulgaris; EC50 (72hr) = 275mg/l; EC10 (72hr) = 11.5mg/l

Selenastrum capricornutum EC50 (72hr) = 12900mg/l; EC10 (72hr) = 440mg/l

Chlamydomonas eugametos: EC50 (48hr) ~ 18000mg/l NOEC (48hr) = 7900mg/l

Gomphonema spp, 48hr EC0 > 395mg/L

Gomphonema gracile, 48hr EC0 > 395mg/L

Navicula cryptotenella, 48hr EC0 > 395mg/L

Ulnaria ulna, 48hr EC0 > 395mg/L

Achnanthidium minutissimum, 48hr EC0 > 395mg/L

 Eunotia cf incisa, 48hr EC0 > 395mg/L

Cympella sp, 48hr EC0 > 395mg/L

Encyonema gracilis, 48hr EC0 > 395mg/L

SEAWATER  -RELIABLE

Skeletonema costatum: EC50 (9 day): 10940 mg/l; NOEC (5 days): 3240mg/l

Ulva pertusa: EC50 (96hr): 14900mg/l, NOEC: 3900mg/l; EC50 3306mg/L

Skeletonema costatum (96hr) EC50: 7000mg/l.

Dunaliella tertiolecta (96hr) EC50:12000mg/l.

Heterosigma akashiwo (96hr) EC50: 1900mg/l.

Tetraselmis tetrathele (96hr) EC50: 15000mg/l.

Isochrysis galbana (96hr) EC50: 12000mg/l.

Chaetoceros calcitrans (96hr) EC50: 5500mg/l.

Pavlova lutheri (96hr) EC50:  9000mg/l.

Key value for chemical safety assessment

EC50 for freshwater algae:

275 mg/L

EC50 for marine water algae:

1 900 mg/L

EC10 or NOEC for freshwater algae:

11.5 mg/L

EC10 or NOEC for marine water algae:

1 580 mg/L

Additional information

In a study which followed the basic principles of a guideline study, two green algae Chlorella vulgaris and Selenastrum capricornutum were exposed to ethanol at sufficient concentrations to enable EC50 values to be established. Exposure was carried out over 5 days with daily measurements of growth characterised by chlorophyll measurement. The dose response curve obtained was very shallow. The four day data presented showed some evidence that the control had passed the exponential growth phase. Basing the results on the 3 day measurements when exponential growth was still clearly evident, ethanol showed slight toxicity to the Chlorella species but not to the Selenastrum species. EC10 (72hr) values were= 11.5mg/l and 440mg/l respectively.  EC50 (72hr) values were 275mg/l and 12900mg/l respectively.

In a well described study, the marine diatom Skeletonema costatum was exposed to ethanol for a period of 5 days and at concentrations sufficient to derive both an EC50 value and a NOEC. From the results, ethanol was not toxic to this species.

In a study designed to assess the 96hr acute toxicity to marine algae Ulva, ethanol was found to have an EC50 of 14.1g/l and an EC0 of 3.9g/l when assessed using an end point of spore release inhibition.

In a study of a number of herbicides, ethanol was used as the vehicle. No adverse effects were seen on the diatoms Gomphonema spp, Gomphonema gracile, Navicula cryptotenella, Ulnaria ulna, Achnanthidium minutissimum, Eunotia cf incisa, Cympella sp and Encynoema gracilis from 48hr exposure to 395mg/L of ethanol compared to the water control.