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Administrative data

Workers - Hazard via inhalation route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
60 mg/m³
Most sensitive endpoint:
repeated dose toxicity
DNEL related information
Overall assessment factor (AF):
3
Modified dose descriptor starting point:
NOAEC
Acute/short term exposure
DNEL related information

Local effects

Acute/short term exposure
DNEL related information

Workers - Hazard via dermal route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
45.3 mg/kg bw/day
Most sensitive endpoint:
repeated dose toxicity
DNEL related information
Overall assessment factor (AF):
9
Modified dose descriptor starting point:
NOAEL
Acute/short term exposure
DNEL related information

Workers - Hazard for the eyes

Additional information - workers

Based on all the available data, sodium acrylate is not subject to classification and labelling requirements under current EU regulations (Directive 67/548/EEC and Regulation (EC) No. 1272/2008).

 

Since sodium acrylate is of low acute toxicity with a median lethal dose value (LD50) being greater than 5000 mg/kg bw by the oral route, the DNEL derived for long-term exposure was considered sufficient to ensure the safety of human workers.

 

No experimental data concerning repeated dose toxicity are available for sodium acrylate. Data from the structural analogue acrylic acid which has been extensively studied, were included for the assessment and DNEL derivation.

 

 

Sodium acrylate is not irritating to skin and eyes. Therefore the local irritation effects of the structural analogue acrylic acid are not expected to occur after repeated application to sodium acrylate. The systemic effects observed in subchronic and chronic drinking water studies were unspecific and not indicative of a specific target organ. In a carcinogenicity study conducted according to OECD TG 451 and GLP regulations the only effect was a marginal reduction in water consumption noted in both sexes of the high dose group (78 mg/kg bw/d). Thus, the NOAEL for this study was set at greater than or equal to the highest dose of 78 mg/kg bw/d (BASF AG 1989). In a 2-generation-study performed according to OECD TG 416 the NOAEL with respect to general toxicity was 240 mg/kg bw/d for the F0 generation parental animals and 53 mg/kg bw/d for the F1 animals and the offspring (F1 and F2 pups). General toxicity was apparent with reduced body weights, food and water consumption in F0 parents at 460 mg/kg bw/d and in F1 parents at 240 and 460 mg/kg bw/d; the only treatment-related pathological finding was a minimal hyperkeratosis of the limiting ridge of the forestomach with a minimal edema of the submucosa of the glandular stomach in both parental generations at 460 mg/kg bw/d indicative of the irritating properties of the test substance. Since sodium acrylate does not possess any irritating properties, these effects are not anticipated for the salt.

The only effects seen in the F1 animals at the mid dose of 240 mg/kg bw/d were marginally lower mean pup weights, reduced body weight gains and reduced water consumption during pre-mating until lactation. In the F2 pups some indications were observed for delays in morphological development as secondary effect to decreased body weights (12 %) and body weight gains.

Regarding these minimal adverse effects at 240 mg/kg bw/d and the rather huge spacing factor of 4.5 to the next lower dose of 53 mg/kg bw/d, the NOAEL of > 78 mg/kg bw/d taken from the chronic study cited above is considered as worst case assumption for a NOAEL and thus, as appropriate starting point. Taking into account the higher molecular weight of sodium acrylate (94.04 g/mol) as compared to acrylic acid (72.06 g/mol), the NOAEL of 78 mg/kg bw/d for acrylic acid was converted to a NOAEL of 102 mg/kg bw/d for sodium acrylate.

 

This value was modified to get the correct starting point for DNEL derivation for the dermal route (route to route extrapolation, oral to dermal). Based on the available in vitro and in vivo data of acrylic acid, dermal absorption through skin was estimated to be max. 25 % of the applied acrylic acid dose. Dermal absorption of the sodium salt is expected to be equal or lower than for the acid. Thus, the absorption difference between oral and dermal route was considered 0.25 resulting in a corrected starting point of 408 mg/kg bw/d. Since a solid data base concerning toxicokinetic behaviour and metabolism is available for acrylic acid, no additional AF for remaining differences was applied. In order to recognize possible interspecies and intraspecies differences in workers, the respective assessment factors of 3 were estimated to be appropriate to ensure safety of the worker (ECETOC TR 86, 2003), since the NOAEL used was derived from a chronic study with only marginal signs of toxicity. The DNEL was calculated to be 45.3 mg/kg bw/d (overall AF = 9).

 

In addition, the NOAEL was modified to get the correct starting point for DNEL derivation for the inhalation route (route to route extrapolation, oral to inhalation), resulting in a corrected starting point of 179.8 mg/m3/d (division by factor 0.38 m3/kg bw; correction for activity driven differences of respiratory volumes in workers compared to workers in rest (6.7 m3/10 m3)). Since a solid data base concerning toxicokinetic behaviour and metabolism is available for acrylic acid, the AF for remaining differences was set at 1. In order to recognize possible intraspecies differences in workers a AF of 3 was estimated to be appropriate to ensure safety (ECETOC TR 86, 2003) resulting in a DNEL value of 60 mg/m3(overall AF = 3).

Since sodium acrylate has a very low vapour pressure and is not expected to cause considerable dust formation, no relevant exposure by the inhalation route is to be expected. Thus, the DNEL for the inhalation route is considered a worst-case assumption.

 

 

Alternatively, the DNEL long-term for the inhalation route can be derived from the structural analogue acrylic acid as worst-case assumption. Since sodium acrylate has a very low vapour pressure and is not expected to cause considerable dust formation, no relevant exposure by the inhalation route is to be expected. In 2006 the German MAK commission determined a scientific OEL for acrylic acid of 10 ppm (corresponding to 39 mg/m3 for sodium acrylate based on its higher molecular weight) based on the irritation of the olfactory epithelium, which was confirmed as a German OEL by the regulatory authorities in 2007 and the European Scientific Committee for Occupational Exposure Limits in 2008. Irritation of the olfactory epithelium is not expected for sodium acrylate.

 

 

 

 

  • ECETOC (2003).Derivation of Assessment factors for Human Health Risk Assessment. Technical Report No. 86, February 2003.

General Population - Hazard via inhalation route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
14.8 mg/m³
Most sensitive endpoint:
repeated dose toxicity
DNEL related information
Overall assessment factor (AF):
6
Acute/short term exposure
DNEL related information

Local effects

Acute/short term exposure
DNEL related information

General Population - Hazard via dermal route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
22.7 mg/kg bw/day
Most sensitive endpoint:
repeated dose toxicity
DNEL related information
Overall assessment factor (AF):
18
Modified dose descriptor starting point:
NOAEL
Acute/short term exposure
DNEL related information

General Population - Hazard via oral route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
5.7 mg/kg bw/day
Most sensitive endpoint:
repeated dose toxicity
DNEL related information
Overall assessment factor (AF):
18
Modified dose descriptor starting point:
NOAEL
Acute/short term exposure
DNEL related information

General Population - Hazard for the eyes

Additional information - General Population

Based on all the available data, sodium acrylate is not subject to classification and labelling requirements under current EU regulations (Directive 67/548/EEC and Regulation (EC) No. 1272/2008).

 

Since sodium acrylate is of low acute toxicity with a median lethal dose value (LD50) being greater than 5000 mg/kg bw by the oral route, the DNEL derived for long-term exposure was considered sufficient to ensure the safety of human workers.

 

No experimental data concerning repeated dose toxicity are available for sodium acrylate. Data from the structural analogue acrylic acid which has been extensively studied, were included for the assessment and DNEL derivation.

 

Sodium acrylate is not irritating to skin and eyes. Therefore the local irritation effects of the structural analogue acrylic acid are not expected to occur after repeated application to sodium acrylate. The systemic effects observed in subchronic and chronic drinking water studies were unspecific and not indicative of a specific target organ. In a carcinogenicity study conducted according to OECD TG 451 and GLP regulations the only effect was a marginal reduction in water consumption noted in both sexes of the high dose group (78 mg/kg bw/d). Thus, the NOAEL for this study was set at greater than or equal to the highest dose of 78 mg/kg bw/d (BASF AG 1989). In a 2-generation-study performed according to OECD TG 416 the NOAEL with respect to general toxicity was 240 mg/kg bw/d for the F0 generation parental animals and 53 mg/kg bw/d for the F1 animals and the offspring (F1 and F2 pups). General toxicity was apparent with reduced body weights, food and water consumption in F0 parents at 460 mg/kg bw/d and in F1 parents at 240 and 460 mg/kg bw/d; the only treatment-related pathological finding was a minimal hyperkeratosis of the limiting ridge of the forestomach with a minimal edema of the submucosa of the glandular stomach in both parental generations at 460 mg/kg bw/d indicative of the irritating properties of the test substance. Since sodium acrylate does not possess any irritating properties, these effects are not anticipated for the salt.

The only effects seen in the F1 animals at the mid dose of 240 mg/kg bw/d were marginally lower mean pup weights, reduced body weight gains and reduced water consumption during pre-mating until lactation. In the F2 pups some indications were observed for delays in morphological development as secondary effect to decreased body weights (12 %) and body weight gains.

Regarding these minimal adverse effects at 240 mg/kg bw/d and the rather huge spacing factor of 4.5 to the next lower dose of 53 mg/kg bw/d, the NOAEL of > 78 mg/kg bw/d taken from the chronic study cited above is considered as worst case assumption for a NOAEL and thus, as appropriate starting point. Taking into account the higher molecular weight of sodium acrylate (94.04 g/mol) as compared to acrylic acid (72.06 g/mol), the NOAEL of 78 mg/kg bw/d for acrylic acid was converted to a NOAEL of 102 mg/kg bw/d for sodium acrylate.

 

This value was modified to get the correct starting point for DNEL derivation for the dermal route (route to route extrapolation, oral to dermal). Based on the available in vitro and in vivo data of acrylic acid, dermal absorption through skin was estimated to be max. 25 % of the applied acrylic acid dose. Dermal absorption of the sodium salt is expected to be equal or lower than for the acid. Thus, the absorption difference between oral and dermal route was considered 0.25 resulting in a corrected starting point of 408 mg/kg bw/d. Since a solid data base concerning toxicokinetic behaviour and metabolism is available for acrylic acid, no additional AF for remaining differences was applied. In order to recognize possible interspecies and intraspecies differences in the general population, the respective assessment factors of 3 and 6 were estimated to be appropriate to ensure safety of the general population (ECETOC TR 86, 2003), since the NOAEL used was derived from a chronic study with only marginal signs of toxicity. The DNEL was calculated to be 22.7 mg/kg bw/d (overall AF = 18).

 

In addition, the NOAEL was modified to get the correct starting point for DNEL derivation for the inhalation route (route to route extrapolation, oral to inhalation), resulting in a corrected starting point of 88.7 mg/m3/d (division by factor 1.15 m3/kg bw). Since a solid data base concerning toxicokinetic behaviour and metabolism is available for acrylic acid, the AF for remaining differences was set at 1. In order to recognize possible intraspecies differences in the general populationa AF of 6 was estimated to be appropriate to ensure safety (ECETOC TR 86, 2003) resulting in a DNEL value of 14.8 mg/m3(overall AF = 6).

Since sodium acrylate has a very low vapour pressure and is not expected to cause considerable dust formation, no relevant exposure by the inhalation route is to be expected. Thus, the DNEL for the inhalation route is considered a worst-case assumption.

 

Then, a DNEL for the oral route was derived by applying an AF for allometric scaling (interspecies differences) of 3 and for possible intraspecies differences in the general population (ECETOC TR 86, 2003) of 6 (overall AF = 18). Since a solid data base concerning toxicokinetic behaviour and metabolism is available for acrylic acid, the AF for remaining differences was set at 1. The resulting long-term oral DNEL was 5.7 mg/kg bw/d.

 

 

 

Alternatively, the DNEL long-term for the inhalation route can be derived from the structural analogue acrylic acid as worst-case assumption. Since sodium acrylate has a very low vapour pressure and is not expected to cause considerable dust formation, no relevant exposure by the inhalation route is to be expected. In 2006 the German MAK commission determined a scientific OEL for acrylic acid of 10 ppm (corresponding to 39 mg/m3 for sodium acrylate) based on the irritation of the olfactory epithelium, which was confirmed as a German OEL by the regulatory authorities in 2007 and the European Scientific Committee for Occupational Exposure Limits in 2008.

This value is regarded to be safe for workers; according to the ECHA Guidance document the intraspecies factor is by a factor 2 higher for general population than for worker. Also the possible exposure time may be by a factor 3 (8 hrs. vs. 24 hrs) and by a factor 1.4 (5 days/week vs. 7 days/week) longer. Therefore an additional AF of 8.4 is added to the OEL value of 10 ppm, resulting in a DNEL for general population of 1.2 ppm (corresponding to 4.7 mg/m3 for sodium acrylate based on its higher molecular weight). Irritation of the olfactory epithelium is not expected for sodium acrylate.

 

 

 

  • ECETOC (2003).Derivation of Assessment factors for Human Health Risk Assessment. Technical Report No. 86, February 2003.