Xylanase, endo-1,4-

Toxicological Summary

Workers - Hazard via inhalation route

Systemic effects

Long term exposure

Hazard assessment conclusion:

no hazard identified

Most sensitive endpoint:

sensitisation (respiratory tract)

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

DMEL (Derived Minimum Effect Level)

Value:

60 ng/m³

Most sensitive endpoint:

sensitisation (respiratory tract)

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

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:

no hazard identified

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

Workers - Hazard for the eyes

Local effects

Hazard assessment conclusion:

no hazard identified

Additional information - workers

Worker DMEL, acute short-term as well as long-term inhalation exposure:

Potential occupational exposure to levels of enzyme, which is toxicologically relevant, is unrealistic due to the stringent work practices and adherence to the voluntary Occupational Exposure Guidelines at or below the established ACGIH (www.acgih.org, the American Conference of Governmental Industrial Hygienists) exposure limit value of 60 ng/m³, based on pure enzyme protein for the benchmark enzyme Subtilisin. This was established due to the endpoint of concern, which is risk of sensitization by inhalation. Worker safety is assured through current proper work practices, engineering controls, and if needed of personal protective equipment. The industry has taken measures to minimize occupational exposure. Worker DMEL has been discussed and concluded by the involved industry (enzyme and detergent manufacturers) in a recent publications (see reference list) and a limit of 60 ng/m³, expressed in pure enzyme protein, was suggested (ref. Basketter et al, 2010) in line with the established ACGIH threshold limit value. Further, xylanase has been tested in an acute inhalation toxicity test in rats and was found to be non-toxic at the highest possible dose, 4.95 mg/L. 

References:

- D.A. Basketter, C. Broekhuizen, M. Fieldsend, S. Kirkwood, R. Mascarenhas, K. Maurer, C. Pedersen, C. Rodriguez & H.E. Schiff: Defining occupational and consumer exposure limits for enzyme protein respiratory allergens under REACH, Toxicology 268: 165-170, 2010.

- Basketter D., Berg N., Broekhuizen C., Fieldsend M., Kirkwood S., Kluin C., Mathieu S. and Rodriguez C.Enzymes in Cleaning Products: An Overview of Toxicological Properties and Risk Assessment/Management. 2012a. Reg. Toxicol. Pharmacol, 64/1: 117-123

- Basketter D.; N. Berg; F. Kruszewski; K. Sarlo; B. Concoby. The Toxicology and Immunology of Detergent Enzymes. 2012b. J. Immunotox., 9, 320-326.

 

Worker DNEL, acute short-term as well as long-term dermal exposure:

The physico-chemical properties of a compound are decisive for the potential percutaneous penetration, in particular factors like ionization, molecular size and lipophilicity. In general, non-ionized molecules easily penetrate the skin, with small molecules penetrating more easily than large molecules. Lipophilicity also facilitates penetration. Investigations of percutaneous absorption of peptides, proteins and other molecules of large size revealed that percutaneous absorption of proteins is extremely low and of no toxicological relevance (ref.Basketter et al 2008; Pease et al 2002, Basketter et al, 2012 a and b). This is further supported by the physico-chemical data of xylanase enzymes. They are proteins with molecular weight above 7,700 D (ref. http://www.brenda-enzymes.info; ec no=3.2.1.8), they have a low logPow value(<0, i.e. low lipophilicity), indicating that they have no bioaccumulation potential and can be anticipated to be readily biodegraded. Thus, systemic exposure following enzyme exposure at occupational exposure levels is without toxicological significance. Xylanase has further been shown to be a non-irritant in an in vivo skin irritation test in rabbits.

References

- Basketter,D.A., English,J.S., Wakelin,S.H., and White,I.R. (2008) Enzymes, detergents and skin: facts and fantasies. British journal of dermatology 158, 1177-1181

- Pease,C.K.S., White,I.R., and Basketter,D.A. (2002) Skin as a route of exposure to protein allergens. Clinical and experimental dermatology 27, 296-300

- Basketter D., Berg N., Broekhuizen C., Fieldsend M., Kirkwood S., Kluin C., Mathieu S. and Rodriguez C.Enzymes in Cleaning Products: An Overview of Toxicological Properties and Risk Assessment/Management. 2012a. Reg. Toxicol. Pharmacol, 64/1: 117-123

- Basketter D.; N. Berg; F. Kruszewski; K. Sarlo; B. Concoby. The Toxicology and Immunology of Detergent Enzymes. 2012b. J. Immunotox., 9, 320-326.

General Population - Hazard via inhalation route

Systemic effects

Long term exposure

Hazard assessment conclusion:

no hazard identified

Most sensitive endpoint:

sensitisation (respiratory tract)

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

DMEL (Derived Minimum Effect Level)

Value:

15 ng/m³

Most sensitive endpoint:

sensitisation (respiratory tract)

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

General Population - 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:

no hazard identified

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

General Population - Hazard via oral 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

General Population - Hazard for the eyes

Local effects

Hazard assessment conclusion:

no hazard identified

Additional information - General Population

Consumer DMEL, acute short-term as well as long-term inhalation exposure:

Industry has documented that respiratory irritation or toxicity due to enzyme preparations is a very rare phenomenon which will not occur at the low concentrations of enzymes found in consumer products as for example detergents. The risk to consumers is considered very low and regarded as toxicologically insignificant (ref. 3, 4, 5). This is supported by the positive safety outcome of a clinical study of the highest reported consumer exposure level, 15 ng/m³, with spot cleaning by spray (ref. 1, 2). Consumer DMEL has been discussed among the enzyme allergy specialists from enzyme and detergent manufacturers and it was concluded by the involved industry partners in a recent publication and the limit of 15 ng/m³

was suggested (ref. 3).

References:

1. Weeks, J.A., Harper, R.A., Simon, R.A., Burdick, J.D., 2011. Assessment of sensitization risk of a laundry pre-spotter containing protease. Cutan. Ocul. Toxicol., 30, 272-279.

2. US SDA.Risk assessment guidance for enzyme-containing products.  2005. Washington, Soap and Detergent Association.

3. D.A. Basketter, C. Broekhuizen, M. Fieldsend, S. Kirkwood, R. Mascarenhas, K. Maurer, C. Pedersen, C. Rodriguez & H.E. Schiff: Defining occupational and consumer exposure limits for enzyme protein respiratory allergens under REACH, Toxicology 268: 165-170, 2010.

4. Basketter D., Berg N., Broekhuizen C., Fieldsend M., Kirkwood S., Kluin C., Mathieu S. and Rodriguez C.Enzymes in Cleaning Products: An Overview of Toxicological Properties and Risk Assessment/Management. 2012. Reg. Toxicol. Pharmacol, 64/1: 117-123.

5. Basketter D.; N. Berg; F. Kruszewski; K. Sarlo; B. Concoby. The Toxicology and Immunology of Detergent Enzymes. 2012. J. Immunotox., 9, 320-326.

Consumer DNEL, acute short-term as well as long-term dermal exposure:

The physico-chemical properties of a compound are decisive for the potential percutaneous penetration, in particular factors like ionization, molecular size and lipophilicity. In general, non-ionized molecules easily penetrate the skin, with small molecules penetrating more easily than large molecules. Lipophilicity also facilitates penetration. Investigations of percutaneous absorption of peptides, proteins and other molecules of large size revealed that percutaneous absorption of proteins is extremely low and of no toxicological relevance (ref.Basketter et al 2008; Pease et al 2002, Basketter et al, 2012 a and b).This is further supported by the physico-chemical data of xylanase enzymes. They are proteins with molecular weight above 7,700 D (ref. http://www.brenda-enzymes.info; ec no=3.2.1.8), they have a low logPow value(<0, i.e. low lipophilicity), indicating that they have no bioaccumulation potential and can be anticipated to be readily biodegraded. Thus, systemic exposure following enzyme exposure at occupational exposure levels is without toxicological significance. Xylanase has further been shown to be a non-irritant in an in vivo skin irritation test in rabbits.

References

- Basketter,D.A., English,J.S., Wakelin,S.H., and White,I.R. (2008) Enzymes, detergents and skin: facts and fantasies. British journal of dermatology 158, 1177-1181

- Pease,C.K.S., White,I.R., and Basketter,D.A. (2002) Skin as a route of exposure to protein allergens. Clinical and experimental dermatology 27, 296-300

- Basketter D., Berg N., Broekhuizen C., Fieldsend M., Kirkwood S., Kluin C., Mathieu S. and Rodriguez C.Enzymes in Cleaning Products: An Overview of Toxicological Properties and Risk Assessment/Management. 2012a. Reg. Toxicol. Pharmacol, 64/1: 117-123

- Basketter D.; N. Berg; F. Kruszewski; K. Sarlo; B. Concoby. The Toxicology and Immunology of Detergent Enzymes. 2012b. J. Immunotox., 9, 320-326. 

 

Consumer DNEL, acute short-term as well as long-term systemic oral exposure:

Proteins are digested into amino acids by gastric juices, digestive enzymes and pancreatic proteolytic enzymes in the lumen of the gastrointestinal tract. As enzymes are simply a class of proteins, enzymes will undergo the same process as any food source based on proteins. Absorption of enzymes in toxicological significant amounts through the gastrointestinal tract is unlikely. Furthermore, enzymes have been used for decades in treatment of both adults and children with exocrine pancreatic insufficiency. Typical enzymatic drugs (e.g. Creon® from Solvay Pharmaceuticals or Pancrease Microtabs from Jansson/Cilaq) contain a combination of the enzymes amylase, lipase and protease – enzymes, which are also used in a wide range of industrial applications. These medical drugs are typically administered orally at therapeutic concentrations i.e. at concentrations where a digestive effect can be expected. Clinical trials and crossover studies confirm the safe use of these compounds in patients, both adults and children, confirming the low toxicity of the enzymes.

For references, please see section 7.1 on Toxicokinetics, metabolism and distribution.