1-bromopropane

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.024 mg/L

Assessment factor:

1 000

Extrapolation method:

assessment factor

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.002 mg/L

Assessment factor:

10 000

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

10 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

0.249 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

0.025 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

0.036 mg/kg soil dw

Extrapolation method:

equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

PNEC oral

PNEC value:

0.041 mg/kg food

Assessment factor:

90

Additional information

PNEC aqua (freshwater, marine water and intermittent releases) are based upon the lowest L(E)C50 from three trophic levels (fish: 24.3mg/l). This LC50 was subject to the appropriate assessment factors to derive the PNEC values.

PNEC stp was based upon the NOEC value taken from the biodegradation study and may therefore be overly conservative.

PNEC sediment (freshwater and marine water) and PNEC soil was calculated using the equilibrium partitioning method in EUSES version 2.1 and was based upon all available physico-chemical and effect data, together with a value for Koc derived from KOCWIN v2.00.

PNEC oral was based upon a repeat dose long-term inhalation value which was corrected for the oral route and subject to an appropriate conversion factor to derive a NOEL value. This NOEL value was the basis for the PNEC oral together with an appropriate assessment factor.

All assessment and conversion factors used in the above PNEC calculations were taken from the ECHA guidance document "Guidance on information requirements and chemical safety assessment; Chapter R.10: Characterisation of dose [concentration]-response for environment" along with appropriate equations and methodologies. Correction factors were taken from the ECHA guidance document "Guidance on information requirements and chemical safety assessment; Chapter R.8: Characterisation of dose [concentration]-response for human health" along with appropriate equations and methodologies.

Conclusion on classification

Classification

Based on all available ecotoxicological data for daphnids, fish and algae, n-propyl bromide should be classified and labelled as R52/53 according to Directive 67/548/EEC and as Aquatic Chronic Category 3 according to the EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008 since the lowest EC50 value for toxicity (fish) is 24.3 mg/L and the substance is not readily biodgradable.

Preliminary PBT/vPvB assessment

An assessment of the PBT status of n-propyl bromide has been made using all available data. The information available suggests that n-propyl bromide does not meet the PBT/vPvB screening criteria as outlined in Annex XIII of Regulation (EC) No 1907/2006.

According to Annex XIII of the REACH text, for a substance to be classified as either PBT or vPvB compound, it must be found to meet certain criteria. A PBT substance is a compound that exhibits all three of the following characteristics:

1)      the half-life in marine water is greater than 60 days, or is greater than 40 days in freshwater or in estuarine waters; or, for soils/sediments, the half-life in marine systems is greater than 180 days, or is greater than 120 days in freshwater and estuarine sediments or in terrestrial soils;

2)      the bioconcentration factor (BCF) is higher than 2000; and

3)      the long-term NOEC for aquatic organisms (freshwater or marine) is less than 0.01 mg/L, or the substance is otherwise classified as carcinogenic, mutagenic, or exhibits reproductive toxicity.

Similarly, a substance classified as a vPvB compound exhibits the following two characteristics:

1)      a half-life in any aquatic environment of greater than 60 days, or a half-life in sediment or soil of 180 days; and

2)      a bioconcentration factor of greater than 5000. 

Persistence

A ready biodegradability closed bottle test (OECD 301D) showed that 1-bromopropane is not readily biodegradable, although 19.2 % biodegradation was achieved after 28 days. A screening prediction using BIOWIN v4.1 predicted the ultimate biodegradation timeframe for 1-bromopropane to be weeks (Biowin3), thereby supporting ultimate biodegradability. Although the Biowin2 (non-linear model) prediction was ‘does not biodegrade fast’ BIOWIN1 and 5 predictions were ‘biodegrades fast’ and Biowin4 (Primary Biodegradation Timeframe) was ‘days-weeks’. In addition 1-bromopropane is predicted to biodegrade fast under anaerobic conditions (BIOWIN 7). It was reasonably concluded that 1-bromopropane can be considered inherently biodegradable.

In addition 1-bromopropane was shown to degrade in water by hydrolysis with a half-life of 562 hours (23.4 days).

Therefore 1-bromopropane is not considered to fulfil the P criterion.

Bioaccumulation

No bioaccumulation data is available for n-propyl bromide, however the substance is considered to have a low potential for bioaccumulation as the tested log Kow value is less than 3. The EPISUITE BCFBAF Program (v3.00) predicts the BCF in fish of 1-bromopropane to be 11.3 L/kg wwt. EUSES (v2.1) predicts the BCF for fish and aquatic biota to be 12.2 L/kg wwt. EUSES (v2.1) predicts the BCF for earthworms to be 2.35 L/kg wwt.

These predicted BCFs are significantly below 2000 indicating a negligible potential for bioaccumulation or subsequent biomagnification in the food chain.

1-bromopropanetherefore does not satisfy the B criterion

Toxicity

No long term aquatic toxicity data is available for 1-bromopropane, but acute data in fish, Daphnia and Algae confirmed L(E)50 values greater than 0.1 mg/l and hence there is no potential to fulfil the T criterion in respect of aquatic effects data. 1-bromopropane is classified as a reproductive toxicant (Category 2 and 3) and is also classified as having the potential to cause serious damage to health by prolonged exposure through inhalation. As such, 1-bromopropane is identified as being toxic and fulfils the T criterion according to the Annex XIII PBT criteria

Summary

In order to be classed as a PBT or vPvB substance, all the criteria must be met. Therefore, based on the present available data, the preliminary PBT assessment concludes that the (screening) criteria for PBT/vPvB are not fully met and that further testing in the scope of the final PBT assessment is not considered to be required. 

1-bromopropane is not classified as P or B and does not meet the PBT or vPvB criteria.