Formaldehyde

Toxicity to terrestrial plants

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to terrestrial plants, other

Type of information:

experimental study

Adequacy of study:

other information

Study period:

2018

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

unsuitable test system

Principles of method if other than guideline:

exposure via nutrient solution to assess an effect on biochemical parameters

Species:

Pisum sativum

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: pea
- Plant family: Fabacea
- Variety: cv. Al’bumen

Test type:

other: biochemical effects in seedling

Study type:

laboratory study

Substrate type:

other: nutritent solution

Limit test:

no

Total exposure duration:

16 d

Remarks:

effect parameters were measured on day 17.

Test temperature:

22 °C

Details on test conditions:

TEST SYSTEM
- Test vessels: 250 ml containers
- Amount of soil: non, hydroculture
- Method of seeding: grown for 5 d in destilles water until appereance of the root, seedlings were placed in container with nutrient solution afterwards
- No. of plants (retained after thinning): 20


NUTRIENT MEDIUM (if used)
- Description: Knop’s nutrient solution (1mM of Ca(NO3)2, 0.25mM of KH2PO4, 0.125mM of MgSO4 and 0.25mM of KNO3), including the addition of microelements (Hoagland’s nutrient solution, from Hoagland and Arnon 1950).
- Renewal: every 4 days

GROWTH CONDITIONS
- Photoperiod: 17 h light
- Light intensity and quality: intensity of 40Wm−2
- Day/night temperatures: 22/17 °С
- Relative humidity (%): 75 ± 3%
- Method of application: the nutrient solution contained the test item at 0.063 × 10–2–0.16 g/L
- Other: to prevent volatilisation of the test item the containers were tightly closed with perforated lids, through which the roots of the seedlings were placed into solution. The diameter of the holes corresponded to the size of the roots


EFFECT PARAMETERS MEASURED:
On day 17, plant growth parameters and the biochemical parameters of leaflets of the fully formed third pea leaf were determined:
- chlorophyll (Ch) content
- carotenoid (Car) content
- the lipid peroxidation (LP)
- growth parameters (GP)


TEST CONCENTRATIONS
- Spacing factor for test concentrations: Neighbouring concentrations differed two-fold.
- Range finding study: in preliminary experiments the maximum used levels of the test item had a considerable toxic effect on the growth of the seedling but did not cause the death of plants (unpublished data).
- Test concentrations: 0.063 × 10^-2–0.16 g/L

Nominal and measured concentrations:

0.63, 1.25, 2.50, 10, 20, 40, 80 160 mg/L and control

With formaldehyde exposure, lipid peroxidation (LP) and chlorophyll (Ch) contents had paradoxical effects (triphasic and multiphase changes, accordingly), while carotenoid (Car) level did not change and (growth parameters) GP exhibited a hormetic response. The date showed that pea parameters display diverse types of non-monotonic responses upon exposure to the same formaldehyde concentrations. High pollutant concentrations (0.08–0.16 g L−1) increased LP and significantly decreased GP (to 2.3–2.5 times compared to the control), while the Ch content was increased. Lower concentrations (<0.08 g L−1) caused a moderate deviation in all parameters from the control (not more than 62%) for hormesis and paradoxical effects.

Conclusions:

High test item concentrations (80 – 160 mg/L) increased the lipid peroxidation rate and significantly decreased growth parameters (to 2.3–2.5-fold relative to the control), while the chlorophyll content was increased. Lower pollutant concentrations caused a moderate deviation in all parameters from the control (not more than 62%) for hormesis and paradoxical effects.

Reference 2

Endpoint:

toxicity to terrestrial plants: short-term

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: Documentation insufficient for assessment

Remarks:

Documentation insufficient for assessment. Method description very short, referring to an earlier publication of this author. However, this study was assessed as reliable in various peer-reviewed chemical reports such as: OECD SIDS Butanol and 2-Propanol. We therefore suggest, to use this study as supportive information.

Principles of method if other than guideline:

Germination inhibition test

GLP compliance:

not specified

Analytical monitoring:

no

Vehicle:

not specified

Species:

Lactuca sativa

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Lettuce
- Plant family: Asteraceae
- Variety: Great lakes

Test type:

other: Germination inhibition test

Study type:

laboratory study

Substrate type:

not specified

Total exposure duration:

3 d

Test temperature:

30 °C

Species:

Lactuca sativa

Duration:

3 d

Dose descriptor:

EC50

Effect conc.:

ca. 583 other: mg/l

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Germination

EC50 = 19.3 mM = 583 mg/l formaldehyde

Reference 3

Endpoint:

toxicity to terrestrial plants: long-term

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

Remarks:

original datat source not available. Data from secondary source

Principles of method if other than guideline:

Exposure to formaldehyde in fog water, 40 days, intermittend exposure

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material (as cited in study report): formaldeyde
- Analytical purity: no data

Species:

Triticum aestivum

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

seedlings

Species:

other: Populus tremuloides

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

seedlings

Species:

Brassica rapa

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

seedlings

Species:

other: Pinus elliotti

Plant group:

Gymnospermae (conifers)

Details on test organisms:

seedlings

Study type:

laboratory study

Total exposure duration:

40 d

Species:

Brassica rapa

Duration:

40 d

Dose descriptor:

LOEC

Effect conc.:

18 other: µg/m3

Species:

Triticum aestivum

Duration:

40 d

Dose descriptor:

NOEC

Effect conc.:

18 other: µg/m3

Species:

other: Populus tremuloides

Duration:

40 d

Dose descriptor:

NOEC

Effect conc.:

18 other: µg/m3

Species:

other: Pinus elliotti

Duration:

40 d

Dose descriptor:

other: promoting effect concentration

Effect conc.:

18 other: µg/m3

Executive summary:

Effects on plants were studied following exposure to formaldehyde in fog water. Seedlings of winter wheat (Triticum aestivum), aspen (Populus tremuloides), rapeseed (Brassica rapa) and slash pine (Pinus elliotti) were exposed to formaldehyde concentrations of 0, 9000 or 27 000 μg/L in fog for 4.5 hours per night, 3 nights per week, for 40 days. Based on an unspecified Henry’s law constant, calculated corresponding atmospheric gas-phase formaldehyde concentrations were 0, 18 and 54 μg/m3, respectively. In rapeseed grown in the formaldehyde fog, significant (p ≤ 0.1) reductions in leaf area, leaf dry weight, stem dry weight, flower number and number of mature siliques (seed pods that produce seed) were observed compared with control plants. The slash pine showed a significant increase in needle and stem growth. No effects were observed in the wheat or aspen at test concentrations.

Reference 4

Endpoint:

toxicity to terrestrial plants: short-term

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

Exposure to formaldehyde in air, 4 weeks

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material (as cited in study report): formaldeyde
- Physical state: gaseous
- Analytical purity: no data

Analytical monitoring:

yes

Details on sampling:

Twice daily, samples of air were pulled at a flow rate of 1.5 L/min for 30 min from each chamber through two bubblers in a series, each containing 20 ml of distilled formaldehyde permeation tube.

Species:

Phaseolus vulgaris

Plant group:

Dicotyledonae (dicots)

Study type:

laboratory study

Substrate type:

other: Clay growing medium

Total exposure duration:

4 wk

Test temperature:

Day: appr. 25°C
Night: appr. 14°C

Nominal and measured concentrations:

average measured concentrations: 78, 128, 239 and 438 μg/m3 in air

Species:

Phaseolus vulgaris

Duration:

4 wk

Dose descriptor:

LOEC

Effect conc.:

78 other: µg/m3

Basis for effect:

growth

Plant leaf area (+18%), leaf dry weight (+16%) and stem dry weight (+31%) were higher in plants exposed to high concentrations of gaseous formaldehyde (438 µg/m3) as compared to control plants. Furthermore, there was an increase in growth of shoots, but not of roots among all concentrations tested.

 

 

Reference 5

Endpoint:

toxicity to terrestrial plants: short-term

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

Exposition of lily pollen to formaldehyde fog for 5 hours, effect parameter: pollen tube length

GLP compliance:

no

Specific details on test material used for the study:

- Name of test material (as cited in study report): formaldeyde
- Physical state: gaseous
- Analytical purity: no data

Species:

other: other terrestrial plant: Lilium longiflorum

Plant group:

Monocotyledonae (monocots)

Study type:

laboratory study

Total exposure duration:

5 h

Species:

other: Lilium longiflorum

Duration:

5 h

Dose descriptor:

LOEC

Effect conc.:

440 other: µg/m3

Species:

other: Lilium longiflorum

Duration:

5 h

Dose descriptor:

EC100

Effect conc.:

1 680 other: µg/m3

Executive summary:

Pollen germination has been shown to be sensitive to various air pollutants. Masaru et al. sowed lily pollen grains (Lilium longiflorum) on culture medium. After beeing exposed to formaldeyhde in a fumigation chamber, for 24 h, pollen tube length was measured. A 5 h exposure to formaldehyde at 0.44 mg/m3 (0.37 ppm) resulted in a significant reduction in pollen-tube length, whereas a 1 h or 2 h exposure was innocuous. When formaladeyde concentration was increased to 2.88 mg/m3 (2.4 ppm), a 1 h exposure caused a decrease in tube length.

Reference 6

Endpoint:

toxicity to terrestrial plants: long-term

Data waiving:

exposure considerations

Justification for data waiving:

the study does not need to be conducted because direct and indirect exposure of the soil compartment is unlikely

Table 1: Mackay Level I calculation (BASF, 2008)

Compartment	Percent distribution in media (%)
Air	1.16
Water	98.8
Soil	0
Sediment	0
Susp. sediment	0
Biota	0
Aerosol	0

 

Description of key information

No exposure to soil organisms is expected.

Additional information

The test item is highly soluble in water (~550 g/L, c.f. 4.8.) and is readily biodegradable (Frauenhofer IME, 2011) therefore an exposure via soil is not expected. In accordance with Annex IX of Regulation (EC) No 1907/2006, testing is not required as the substance is not persistent in this compartment, due to physico-chemical properties and the proven ready biodegradability. This is underlined by valid Mackay Level I distribution modelling (BASF, 2008). According to this calculation soil is not a target compartment of the test item. When released into the environment 98.8 % will remain in the water phase and 1,16 % will evaporate to the air (see table 1). In order to this, a distribution to soil and sediment is not expected. In addition, the test item has a low log Kow (0.35, Hansch et al., 1995) and does not tend to bioaccumulate in organisms. In conclusion, exposure of soil organisms is very unlikely.

Nevertheless, reliable studies on the short- and long-term toxicity of the test item to plants are available. These studies are not adequate to cover the endpoint and are used only as supporting or other information.

Short term toxicity to plants:

A 5 h exposure to formaldehyde at 0.44 mg/m3 (0.37 ppm) resulted in a significant reduction in pollen-tube length, whereas a 1 or 2 h exposure was innocuous. When the formaldehyde concentration was increased to 2.88 mg/m3 (2.4 ppm), a 1 h exposure caused a decrease in tube length (Masaru et al., 1976).

The most sensitive effect for terrestrial organisms resulting from exposure to formaldehyde in air was an increase in the growth of shoots, but not of roots, of the common bean (Phaseolus vulgaris) after exposure to average measured concentrations of 78, 128, 239 and 438 μg/m3 in air (day: 25°C, 40% humidity; night: 14°C, 60% humidity) for 7 hours per day, 3 days per week, for 4 weeks, beginning at the appearance of the first macroscopic floral bud, 20 days after emergence (Mutters et al., 1993).

In addition, the effect of the test item on biochemical pararmeters in Pisum sativum were determined (Erofeeva, 2018). High test item concentrations (80 – 160 mg/L) increased the lipid peroxidation rate and significantly decreased growth parameters (to 2.3–2.5-fold relative to the control), while the chlorophyll content was increased. Lower pollutant concentrations caused a moderate deviation in all parameters from the control (not more than 62%) for hormesis and paradoxical effects.

Long term toxicity to plants:

Effects on plants were also studied following exposure to formaldehyde in fog water. Seedlings of winter wheat (Triticum aestivum), aspen (Populus tremuloides), rapeseed (Brassica rapa) and slash pine (Pinus elliotti) were exposed to formaldehyde concentrations of 0, 9000 or 27 000 μg/L in fog for 4.5 hours per night, 3 nights per week, for 40 days. Based on an unspecified Henry’s law constant, calculated corresponding atmospheric gas-phase formaldehyde concentrations were 0, 18 and 54 μg/m3, respectively. In rapeseed grown in the formaldehyde fog, significant (p ≤ 0.1) reductions in leaf area, leaf dry weight, stem dry weight, flower number and number of mature siliques (seed pods that produce seed) were observed compared with control plants. The slash pine showed a significant increase in needle and stem growth. No effects were observed in the wheat or aspen at test concentrations (Barker & Shimabuku, 1992).