(5-ethyl-1,3-dioxan-5-yl)methyl acrylate

Toxicological Summary

Workers - Hazard via inhalation route

Systemic effects

Long term exposure

Hazard assessment conclusion:

no hazard identified

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

low hazard (no threshold derived)

Acute/short term exposure

Hazard assessment conclusion:

low hazard (no threshold derived)

DNEL related information

Workers - Hazard via dermal route

Systemic effects

Long term exposure

Hazard assessment conclusion:

no hazard identified

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

medium hazard (no threshold derived)

Acute/short term exposure

Hazard assessment conclusion:

medium hazard (no threshold derived)

Workers - Hazard for the eyes

Local effects

Hazard assessment conclusion:

no hazard identified

Additional information - workers

Local effects:

(5-ethyl-1,3-dioxan-5-yl)methyl acrylate is classified as a skin irritant and a moderate skin sensitizer. Following Echa Guidance on information requirements and chemical safety assessment Part E, a moderate risk for local acute exposure was assumed due to the skin sensitizing properties cat. 1B, which are considered more severe than skin irritation. Since the value of the dose response data from the LLNA is limited, a qualitative risk assessment is performed for local dermal effects.

No data exists for effects on the respiratory tract. Because of the low vapour pressure of 0.6Pa, no irritation is expected even if the air is saturated. The maximum amount of vapour in air is 49mg/m³. The NOAEL for local irritation for the stomach mucosa was 100mg/kg b.w. Irritation is not linked to the total amount, but to the local concentration of the substance. In the repeated dose study, 100mg/kg b.w. were applied at a concentration of 25mg/ml or 25x10e6mg/m³, which is far above the saturated vapour concentration (Factor of 500000), even if the substance was diluted in the stomach by residual food, considering a factor of 5 for intraspecies differences, or if the lung should turn out to be more susceptible to irritation. No skin sensitization was observed at 2.5%, which equals a concentration of 25x10e3mg/m³. Though this value is lower than the estimation for irritation, it is still 500times above the maximum vapour concentration. On the other hand, if aerosols are created, effects on the lung cannot be ruled out. This is considered in the qualitative assessment performed for possible local effects by inhalation, i.e., respiratory protection is required whenever exposure to aerosols might occur.

Systemic effects:

No signs of systemic toxicity were observed in an acute dermal and oral study and a repeated dose OECD 422 screening. In the acute toxicity study one female died due to extensive bleeding in the glandular stomach after a single dose of 2000mg/kg. The remaining animals showed an impaired general state mostly up to 5 hours after dosing, probably also due to the irritant properties of the test substance. In a test study to select the doses for the OECD 422 study, 1 of 3 animals died on day 13 after daily exposure to 1000mg/kg and ulcerations in one animal receiving 500mg/kg b.w. were considered severe enough to cause death after prolonged exposure. Thus 250mg/kg b.w. was selected as the maximum dose in the OECD 422 screening test. This dose also led to minimal irritation in the forestomach in 7 out of 10 males, but to no systemic toxicity in males or females. Though lack of systemic toxicity might also be due to the low maximum concentration tested, local effects occur long before any systemic effects can be observed. Since the substance will not accumulate in the body because of its moderate logPow of 1.9 and good water solubility, which is also true for the proposed metabolic products acrylic acid and 5 -ethyl-1,3 -dioxane-5 -methanol (see discussion on toxicokinetics), no systemic effects are expected even if the exposure time is increased. Thus protection against local effects, i.e., irritation and sensitization, is considered sufficient to also protect against any possible systemic effects. This is in line with Echa Guidance on information requirements and chemical safety assessment Chapter R.8, which states in section 8.1.2.6, that no DNEL for systemic effects can be derived from studies, where local effects prevent appropriately high systemic exposure to occur.

General Population - Hazard via inhalation route

Systemic effects

Acute/short term exposure

DNEL related information

Local effects

Acute/short term exposure

DNEL related information

General Population - Hazard via dermal route

Systemic effects

Acute/short term exposure

DNEL related information

General Population - Hazard via oral route

Systemic effects

Acute/short term exposure

DNEL related information

Additional information - General Population

As there are no consumer uses, no consumer DNELs were derived.